Fresh carb rebuild and Engine Knocking


Information and questions on GL1100 Goldwings (1980-1983)
  • Sponsored Links
dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Sun Oct 02, 2016 8:27 pm



Topic Summary: Fresh carb rebuild on a naked 1983 GL1100, and engine has a knocking noise which seems to come from the back of the engine, near the stator.

I own a 83 Interstate which runs great, and just purchased another one which is a stripped-down version, but also an 83. This naked Wing only has 30,000 miles, and based on the great condition all the components, I think it is actual mileage. She has been sitting along time, so I drained the old gas from the tank, and was happy to see that there is not a speck of rust in the tank. I drained the foul gas out of the carb bowls, and then rigged up a small container of fresh non-ethanol gas for the fuel pump to drink from. Also injected fresh gas down the gas line and into the carb bowls. Cranked her up, but had to keep squirting gas into the air box or on the air filter to keep her running. Got her warm enough to drain the old engine oil. Oil was pretty bad looking, and about 3/4 quart too much. So, I was thinking that maybe the carb float needle valves had been sticking and gas was flooding over the bowls and into the engine crankcase. Not sure if it was that, or if the POS just used too much oil.....but at least it wasnt water from the cooling system.

The engine did run on this first start-up, but did have a bothersome knocking noise.

So, I opted against the SeaFoam and went ahead and pulled off the carbs for a good inspection of what was going on inside them. Glad I did! 3 of the needle valves were seized shut.....all except #3 which is the first to get gas from the fuel pump. All the slow idle jets were clogged up, and the others were not very pretty either. This would not have been a candidate for SeaFoam.

Did a thorough, time consuming carb clean and rebuild.....but I did not split the two sides. Got the carbs put back on today. Also adjusted the valves (which only need minor tweeking). I drained the old coolant out and replaced the O-rings on the coolant metal pipes that are located under the carbs.....with the carbs out, its a perfect time to take care of that, especially since they leaked a bit just by putting minor pressure on the pipes).

So, I cranked up the old bike today, and she fired right up. However, I still have a knocking noise which seems to come from the rear of the engine, near the stator. To add more evidence, I had noticed when adusting the valves that the stator cover cap was missing, and when I put a 10mm socket to turn the stator shaft to spin the engine to the T1 timing mark, the stator nut was a bit loose. One turn and it was tight again. So, I was thinking that I had something wrong inside the stator.....something loose maybe. The stator is still working, as it did charge the battery during the brief 5 minutes that I had her running.

I was reading many posts on this site, and many people say that a carb sync might take away these knocking sounds. I have the gauges and will give that a shot tomorrow. If the carb sync as no affect on this knocking noise, what else would you suggest? I really dont want to deal with pulling the engine out and digging into the stator to find out the problem. Would love to keep this bare-bones 83 1100, but might have to sell if it turns out to be stator-related.

Thanks for any advice.



4wred
Posts: 151
Joined: Sat May 17, 2014 8:42 pm
Location: lancaster pa
Motorcycle: 82 goldwing aspencade
82 aspy turned naked (sold)
89 suzuki gsx 1100F

Re: Fresh carb rebuild and Engine Knocking

Postby 4wred » Mon Oct 03, 2016 7:52 am

Sounds like you just need a good sync.The fact that the stator bolt tightened up is a good sign.Assuming you did everything rite with the carbs you should be good to go.

sportsfreaked
Posts: 219
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: Fresh carb rebuild and Engine Knocking

Postby sportsfreaked » Mon Oct 03, 2016 12:11 pm

That knocking noise has to do with the primary chain most likely. Hopefully the sync of the carbs will take care of it.
Is the knocking noise only on start up at low idle? It doesn't knock as the rpms go up does it? The old 1100 I had that I gave to my son has that knock. It's not as bad since littlebeaver helped me sync the carbs on it. It does need a carb rebuild but the kid doesn't have the money for it. The bike rides fine just a little annoying knock at low idle when taking off.
Thanks to all who answer and help. It is greatly appreciated!
Ed

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 03, 2016 1:58 pm

4wred and Sportsfreaked: Thanks for your input. Today I solved the knocking problem. I discovered the stator bolt to be loose again, so this time I put the bike in 1st gear and and had her on the kick stand so there was some weight on the rear tire. I tightened the stator bolt and did a few solid jerks on it to cause the rear tire to spin a bit on the concrete. (Is there a better way to get enough torque on that onry stator bolt?)

So I then proceeded to get out the Carb Sync gauges to give her a good sync. Upon starting, the nasty knocking noise was totally gone.......huge relief knowing it was only a loose stator bolt. Here is a pic of the carb sync gauges set up ready for the procedure:

Ready to Sync the Carbs
Ready to Sync the Carbs


I found that you must hang the set of vacuum gauges by a bungie cord or string to prevent vibrations from the engine causing the needles to vibrate all over the place. Once strung up, I could tweek the small valves to get the needles very stable.

Here it is before tweeking the carb screws and idling around 1000 RPMs: Actually pretty close, but some adjustments were needed:

Reading at 1000 RPMs before adjusting screws.
Reading at 1000 RPMs before adjusting screws.


Got her tweeked, and the engine sounds fantastic. HOWEVER.............as you can see in this picture, she was pumping out too much whitish "fog", which actually looked normal on first start up, but the fog then got a bit thicker after running about 5 minutes. You can see that the white fog was thicker coming out the muffler for Cylinders 1 and 3:

White fog coming out No. 1 & 3 Cylinder Muffler
White fog coming out No. 1 & 3 Cylinder Muffler


White fog
White fog


At first I thought that water was getting past the head gasket and into the cylinders, and the fog was caused by water being burned. I then looked down at the engine oil level window in front of the rear brake foot lever, and saw that the engine oil had gone from being right in the middle of the two marks, and was now way up at the top level mark. So something was mixing with the engine oil and causing it to rise on the oil level mark. Another clue is that the carbs were leaking gas from Cylinders 1 and 3 (the same ones that were puffing out the thick fog). So, I was thinking that something was screwed up with my carb rebuild, and allowing alot of raw gas to flow down into the right side (1 and 3) cylinders, which would cause the constant whitish fog to come out the muffler (as if you still had the choke lever on the entire time).

Before dealing with this new problem, I finished up the carb sync, and got her pretty close:


Carbs synced pretty close
Carbs synced pretty close


For some reason, Carb No. 2 was had alot more needle movement (on the vacuum gauge) up and down when I revved the engine....the other Carbs moved, but not as crazy as Carb No. 2. Anyone have any reason for this?

I shut the engine off (as it had sucked up almost the entire half gallon of non-ethanol gas I had rigged up). That is another clue......she was using more gas than typical during the carb sync process. A half gallon in 5-10 minutes is a bit extreme......so, gas must have been leaking past the carbs and into the engine crankcase.

I drained the engine oil to verify that it was gas and not water in the oil. Here is what came out:

Oil drained after the carb sync process.....Gas in Oil?
Oil drained after the carb sync process.....Gas in Oil?


To the experts out there......does the streaking in this oil give indication that gas is mixing with it? I poured the oil into clear containers, and cannot detect any water at the bottom. It was over half a quart too much, so if it wasnt water, its gotta be gas......right?

Now, my next question is How does so much gas leak past the cylinders when she is running and get into the crankcase????? I will have to pull off the carbs again, but can anyone suggest what the problem could be.....where to look?

Thanks.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 03, 2016 2:08 pm

Also, here is a good trick to get another cup of old oil out of the engine crankcase.....run the rear tire up on a 2x8 so the oil drains real good toward the front drain plug:

Draining the last cup of oil
Draining the last cup of oil


Here are the two leaking carbs....it seems the leaks are someplace above the carb bowl gaskets
The two leaking carbs, No. 1 & 3
The two leaking carbs, No. 1 & 3

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 03, 2016 6:01 pm

Proper Carb Float Adjustments:

I also have another question which could be related to the leaking No. 1 and No. 3 Carbs. When I rebuilt these carbs, it appeared to me that they had never been off the bike before.....there was no evidence of damaged phillips screw heads, or anything that could show evidence of someone pulling them off in the past. The puzzling thing is that all the carb float heights were all the same, and way above what the shop manual states. I think the shop manual states that the float clearance should be 15 mm, but these carb floats were all close to 25mm. It looked as if the float "tounges" which you bend to change the float height were all the same, and never bent to make the 15mm specification. So, I did bend them some to get the float height spec closer to the 15mm spec. However, doing this causes the carb bowls to fill up higher with fuel before the needle valve closes the gas flow.

Is the 15mm spec not correct, and 20-25mm better to prevent the carbs from over-flooding?

sportsfreaked
Posts: 219
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: Fresh carb rebuild and Engine Knocking

Postby sportsfreaked » Mon Oct 03, 2016 8:38 pm

Dwight I'm sorry but I'm no carb expert. I have seen posts where fuel was leaking past the jets into the crankcase I THINK???. I'm hoping someone else will chime in.
Thanks to all who answer and help. It is greatly appreciated!
Ed

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 03, 2016 8:49 pm

sportsfreak.....thanks for commenting. I now think that the gas is leaking through the fuel pump and going straight into the crankcase oil. Since this leakage had to occur when the engine was running (since I was using an external 1/2 gallon jug tied to the foot peg, there was no way the tank fuel could run downhill thru the carbs), there is no way all that gas can sneak past the pistons of a running engine. Yes, the right bank was running super rich, and thus the white fog out the pipe, but there is no way 1/2 - 3/4 qt. of gas could get into the engine oil with the engine running. So, it has to be coming in via the fuel pump gasket.

That is what I plan to check next. Now wondering if I can find replacement diaphrams/gaskets for the fuel pump.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Tue Oct 04, 2016 5:02 pm

Can someone tell me if they think the gas is getting into the engine crankcase by going thru the fuel pump? If so, do they sell rebuild kits for the fuel pump (1983 GL1100)?

Also, my question about the carb floats.......should I ignore the factory 15mm setting and put them back to 20-25mm?

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Thu Oct 06, 2016 10:03 pm

Sure wish someone would give me some imput regarding fuel leaking into the crankcase.....Im still a bit stumped.

I took the fuel pump off today:

Fuel Pump about to come off
Fuel Pump about to come off


Here you can see the shaft that drives the fuel pump and tach.....the end has a "lobe" that causes the fuel pump push rod to move back and forth, which causes the diaphram to vibrate which sucks the gas from the tank up to the carbs. By the way, my fuel pump also had about 3 tablespoons of oil inside it, in the chamber where the tach gear meets the valve cover shaft.

Drive to Fuel Pump & Tach
Drive to Fuel Pump & Tach


I opened up the fuel pump to look at the diaphram......and it seems to be in great shape. Looking at the diaphram and entire fuel pump, I cannot see how over a half quart of fuel could be leaking internally and going back into the crankcase. Also, as a testiment to the power of the diaphram in this pump, when I was using a smaller 1 qt container to hold gas, and had a temporary fuel line going into it, I accidentally closed the air weep hole in the container while the engine was running. The fuel pump was sucking gas from this container and after a few minutes I noticed that the container was "imploding", it was crushing in on itself as a result of the fuel pump sucking out all the gas and not letting air in. So, I think the diaphram in the pump is fine.

So, how in the world did over a quart of gas get from the next gas container ( a 1/2 gallon container, with a proper vent) and into the engine crankcase? If the engine was running, isnt it impossible for that much gas to pass through the running pistons?

Any Sherlock Holmes reading this who can come up with an idea?

Thanks.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Thu Oct 06, 2016 10:06 pm

Pic of fuel pump opened up, showing diaphram:

Fuel pump opened
Fuel pump opened

User avatar
WingAdmin
Site Admin
Posts: 17050
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: Fresh carb rebuild and Engine Knocking

Postby WingAdmin » Fri Oct 07, 2016 3:22 pm

Gas in the crankcase is virtually always caused by leaky carburetor float valves allowing gas to drip into the cylinders when the bike is sitting, where it easily migrates past the piston rings and into the crankcase.

Obviously fixing the affected float valves will fix the issue, but in the meantime, make sure you turn off your fuel petcock when you park your bike, to prevent gas from gravity feeding from the fuel tank into the carbs.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Fri Oct 07, 2016 4:35 pm

WingAdmin......Thanks for replying. I agree with all you said, however in my case I had only a temporary half gallon jug of gas rigged up and sitting on the foot peg. I just put the rebuilt carbs back on, and thus there was no gas available to drip past the float, down the cylinders, and into the crankcase. I only had the bike running for about 10 minutes (as shown in the pics above), and during that time over a half quart of gas seeped into the crankcase somehow.

I had just changed the oil, and it was exactly between the high level and the low level on the sight glass. After running, the oil level was way up on the high level mark. I drained the oil, and it was not water in the oil. I kept the old oil in clear containers, and there is no water on the bottoms.

So, even if the No. 1 and No. 3 carbs are dripping some gas under the bowls, and allowing the engine to run rich on that side, how could a quart of gas make its way into the crankcase while the engine is running? I thought the only way would be through the fuel pump, with gas going past the Tach gear drive, and into the crankcase beside the valve cover. However, I got about 3 tablespoons of oil from around the tach gear drive, and no sign of gas being down there.

I am totally blown away with this mystery......how could that gas get into the engine crankcase?

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Sat Oct 08, 2016 5:06 pm

Update on the gas leaking into the crankcase:

I pulled off the fuel pump, and thoroughly inspected.....and all components seem good. Even put some lung air pressure into the intake port and I could hear the small spring/diaphram opening under slight air pressure. Did the same with the out-take port, and it only required a bit of suction to open up. Then used a long piece of gas line and attached to the intake port, and filled with gas. The gas did find its way to the outtake port, but there was no leaking down into the lower base area where the Tach cable hooks up. So, it seems that the gas was not getting into the crankcase via the fuel pump.

I pulled those wascully carbs off again to find out why No. 1 and No. 3 were leaking.

While the carbs were off, I created two holes in the front radiator plate to allow a phillips screwdriver to go through so I can easily tighten the air intake boots. It was a bit frustrating last time, as the phillips screwdriver could only engage the screw at an angle, not allowing a good turn and good torque on the boot. Pics:

Screw on boot
Screw on boot



Drilled hole for screwdriver
Drilled hole for screwdriver



Left side hole
Left side hole


Has anyone else drilled these holes to make life a bit easier?

User avatar
spiralout
Posts: 1050
Joined: Sun Feb 17, 2013 6:41 pm
Location: Alabama
Motorcycle: 1975 GL1000 (gone)
1980 GL1100I (with '77 1000 engine)
1996 GL1500 SE

Re: Fresh carb rebuild and Engine Knocking

Postby spiralout » Sun Oct 09, 2016 9:58 am

dwight007fchr wrote:
Has anyone else drilled these holes to make life a bit easier?

I just position them so that the screw head on the front runner's clamp is facing up and the rear runner's clamp screw is facing to the rear. I can get a good straight shot at them that way.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Sun Oct 09, 2016 5:34 pm

Spiral...........You are totally right! I must have been having a severe brain pfart and never thought of rotating the front clamps so I could come down from the top with a phillips screwdriver. One of those "daaaaaaaaaaaaaaaaaaaaaa" moments. I guess they are installed horizontally from the factory, but that does not mean the screws/clamps have to stay horizontal. Well, I guess I now do it either way.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Sun Oct 09, 2016 5:48 pm

Spiral....Got a question for you from my prior posts. Guess not many people have much interest in the "gas in the crankcase issue". I inspected the fuel pump, and I do not think the gas was entering the crankcase from the fuel pump. The only other way would be from flooding carbs. However, the engine was running the entire time, and the gas was coming from a half gallon jug mounted on the foot peg. No way it leaked into the engine before start up, since there was no gas hooked up before start up.

Is it possible for flooding carbs to to allow the engine to run super rich, and at the same time dump gas down around the intake valves where it then leaks into the valve covers and then down into the crankcase?

I have the carbs off now, and am looking for any possible missing ORings or what was causing the carbs to leak (I installed brand new float valves and the brass seats in, and hope they were not leaking). This time I will run a fuel line toward the cieling and fill with gas and look for leaks before installing the carbs.

User avatar
mytown
Posts: 156
Joined: Wed Oct 31, 2012 11:54 am
Location: Carbondale, Illinois
Motorcycle: 1982 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby mytown » Sun Oct 09, 2016 10:51 pm

You're analysis is putting so much reliance on a single event that I would do it again. I'm speaking of your observation that something did indeed increase the volume of liquid in your oil while the bike was running and that that something is positively gas. Keep in mind that at the time you were not testing for that particular event happening and may have bypassed one or another critical control. Also the phenomenon seems to be defying explanation to a point that suggests it may not be occurring at all. Another reason I question (not doubt) your conclusion is the relatively small amount (1 pint) that you are certain increased the amount of liquid in the crankcase while it was running. And this is based on checking the amount by observing the oil level window, a method I find can be very unreliable. It sure looks like something is in the oil and that that something is not mixing with it, but my understanding is that gas quickly evaporates out of the crankcase. Regarding the float levels. If I understand correctly, 25mm would lower point at which the float tang contacts the float needle. Would that not put more force on the bottom of the needle valve and could that additional force explain why three of four were stuck? The chance that this occurred at the factory is unlikely. The overadjustment of the float levels could have been some PO's remedy for leaky float needles thinking that adding pressure to the bottom of the needles would stop the overflow from happening.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 10, 2016 7:19 am

mytown.....Thanks for the input. Good advice.

1. Yes the analysis was technically on that single event. Also, the original oil which was changed was also a bit too much and thin and with no water mixed in.

2. It did appear that "something" was increasing the amount of oil in the crankcase, and since it was not water/antifreeze, then I assumed it must be gas. However, "maybe" there is a way for oil to leak back into the crankcase from that loose stator bolt? I dont know, but I guess I should not rule that out.

3. I will have to do as you say and slap those carbs back on (after bench testing for leaks), and see if the engine level oil rises again.

4. As you said, I cant rule out that this event is not really happening.....that gas is not mixing with the engine oil. I wish I had a way to test the oil that I drained out to get a percentage of gas that is in it. Maybe just toss a match at it and compare how it burns as opposed to plain engine oil.......well, I guess I will save that test for last resort.

5. Float levels: Yep, if someone had adjusted them all to around 25mm, that would make the valves shut with less fuel in the carb bowls.....and probably would make the carbs run lean as a result. Good point you made......there would be a bit more upward force on the rubber-tipped valves/needles, and that could cause them to stick over time (especially when the bike sits for years). Yep, could have been the POS just trying to remedy leaking float needles. Since I put brand new seats and needles in, I will be sure they are set to the factory specs of 15.5mm.

Will let you know what happens after I get the carbs on and have her running again.
Thanks.

rorke
Posts: 3
Joined: Thu Jun 10, 2010 8:29 am
Location: Brooks, Alberta
Motorcycle: 2007 GL1800
1980 GL1100

2007 GL1800
1980 GL1100

Re: Fresh carb rebuild and Engine Knocking

Postby rorke » Mon Oct 10, 2016 7:21 pm

I have found that worn valve guides will let fuel into the oil. not sure as to the amount. Before I made this discovery I sync'ed the carbs and it ran OK. But there was smoke from the exhaust. Check that the spark plugs are actually firing as this might cause the knock sound. I have replaced the heads with good guides but have not installed the overhauled carbs to see how it all works. Just another thought

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Mon Oct 10, 2016 8:24 pm

rorke........Now your talkin......good info about worn valve guides letting gas get into the engine oil. So, if I had two floats stuck wide open and the fuel pump pushing gas down into the intake pipes, then as the intake valves opened/closed, then the gas could find its way down the valves and into the area under the valve covers, where it would then mix with the engine oil.

I bet if I removed the valve cover on the right side, it may have the appearance of gas flushing it clean, and maybe no engine oil lying on the low side of the cover since the gas would have flushed it clean (maybe). I might remove it and see if there is any evidence of gas getting into it.

rorke
Posts: 3
Joined: Thu Jun 10, 2010 8:29 am
Location: Brooks, Alberta
Motorcycle: 2007 GL1800
1980 GL1100

2007 GL1800
1980 GL1100

Re: Fresh carb rebuild and Engine Knocking

Postby rorke » Mon Oct 10, 2016 10:36 pm

the fuel pump does not have the pressure(about 2 lbs) as do the pistons in their operation. the fuel pump keeps the float chamber full in the carbs only. the fuel is vaporized in the carbs and the excess that is not burned is forced by the bad guides, the other is exhausted as unburned and appears as a whitish smoke.(flooding). this was happening on my 83 1100I. The float level is critical and should be set to the manufacturing specs.(15mm). this will prevent flooding and excess gas in the carb body chamber. backfires are interesting without the filter and cover on. carb syncing is critical as to the knocking and ignition process.(timing should be accurate). head removal is quite involved and gaskets are now quite expensive as they are not OEM anymore. not impossible if you are handy and have the time. carb overhaul using Randakk carb kits gives excellent carb operation. again $$$.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Tue Oct 11, 2016 7:16 am

rorke.......Even at only 2lbs, that little fuel pump can put alot of gas up into those carbs, and if the floats stick open on one side, thats alot of extra gas that has to go someplace. Why dont these carbs have an overflow pipe for when the bowls get too high with gas? This would help reduce the amount of gas that flows down to the pistons/engine.

Backfires.....you are so right about those "interesting" backfires when the filter is off, especially when you spray some gas down the hell hole before cranking her. Seeing a 1 foot tall flame burning is not a pleasant experience, especially when you dont have an old towell handy to put it out.

dwight007fchr
Posts: 435
Joined: Mon Nov 15, 2010 9:43 pm
Location: Culpeper, Va
Motorcycle: 1983 1100 Goldwing Interstate

Re: Fresh carb rebuild and Engine Knocking

Postby dwight007fchr » Tue Oct 11, 2016 5:45 pm

I need some suggestions regarding this leaking carb:

carb floats
carb floats


I checked all the carb float valves and they were working fine. I had the bowls off with the carb up-side-down (as in picture above) and blew into the gas line (put a bit of air pressure into the line) as I moved each float upward to its "open" position. When I did, I could hear the air begin to hiss out of each of the float valves. As I let the float go back down, the air stopped. So, they are all working fine based on air flow.

I then put the bowls back on, and flipped the carb right-side-up, and attached a long piece of gas line and used a bottle to add gas to the line. The carb bowls filled up, and then carb No. 3 (the one where the fuel line connects to) began to leak gas. The gas was flowing below the butterfly and dripping out the end. It was also leaking out of the brass fitting (in pic at tip of my finger), and also appeared to be leaking higher up around the carb.

Gas Leaking out of Carb No. 3
Gas Leaking out of Carb No. 3


It was only leaking around the No. 3 carb until I put a screwdriver under it to tilt it some. Then, gas also leaked out of Carb. No 1:

Gas leaking out of Carb No. 1 when tilted some
Gas leaking out of Carb No. 1 when tilted some


Here you can see alot of gas sitting in the main air box chamber, right beside Carb 3:

A lot of gas sitting in the main air chamber beside Carb 3
A lot of gas sitting in the main air chamber beside Carb 3


I hope to get some advice as to what could be causing this big leak. I believe the float valves are working fine. Is there something else that could allow the leak assuming that all the carb float valves are closing properly?

User avatar
spiralout
Posts: 1050
Joined: Sun Feb 17, 2013 6:41 pm
Location: Alabama
Motorcycle: 1975 GL1000 (gone)
1980 GL1100I (with '77 1000 engine)
1996 GL1500 SE

Re: Fresh carb rebuild and Engine Knocking

Postby spiralout » Wed Oct 12, 2016 12:22 pm

I read in your first post that you didn't split the plenum. That could be one source of the leak. I don't know jack about 1100 carbs, even though I have two sets in the garage, I've never worked on them. I have a 1000 motor in my 1100, instead. I do think there're three carb to plenum o-rings on the 1100s. Did you replace those when you overhauled them?

As far as that much fuel in the oil from when it was running seems impossible. I bet if you get your carbs right and change and fill the oil to the proper level, this mystery won't happen again.




Return to “GL1100 Information & Questions”




Who is online

Users browsing this forum: Johnyy Smoke and 1 guest