Carburetor flooding


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CRAFFS
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Carburetor flooding

Post by CRAFFS » Mon Aug 05, 2019 12:07 pm



Fuel is "streaming" from the carburetor float chamber overflow tube (the bike has been standing for 3 years). Obviously the float(s) or needle(s) are stuck. Before removing the carburetors :(((, any "tips/short cuts" on how to solve this problem??? I had the same problem on some of my older bikes and it was quickly solved by tapping the float bowls with a screwdriver (plastic) handle. I got advice to blow compressed air up into the overflow tube but I am a bit "scared" to do this. Any ideas?? Thanks, Johann



Rodzim
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Re: Carburetor flooding

Post by Rodzim » Mon Aug 05, 2019 11:53 pm

I bought 2 rebuild kits from amazon for $30, my bike has never ran better

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ct1500
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Re: Carburetor flooding

Post by ct1500 » Tue Aug 06, 2019 4:27 am

It is never a wise idea to blow compressed air into an assembled carburetor and would likely not remove the crud causing the problem anyway.
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DenverWinger
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Re: Carburetor flooding

Post by DenverWinger » Tue Aug 06, 2019 5:58 am

Might disconnect and plug the vacuum line from the fuel petcock, then start the engine and run the carbs out of gas. Use the "choke" when the engine starts to sputter. This drops the floats to the bottom and opens the needle valves wide.

Then reconnect the vacuum line and start engine again. Sudden inrush of fuel may wash some crud from the float needle valves.

A good dose of Seafoam (or whatever other fuel system cleaner available in SA) added to the fuel probably wouldn't hurt either.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

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CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Wed Aug 07, 2019 4:58 am

Rodzim, ct1500 & DenverWinger, Thank you very much for your comments.

I compiled a rather detailed reply on what I have done so far but for some or other reason I could not submit it??
However, I will first try DenverWinger's advice, ct1500, I agree with your comment, Rodzim, once I have worked through the whole fuel system, I most properly will have to remove & strip the carbs (in other words, order the re-build kits).
Thanks again, will keep you posted. Johann

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Re: Carburetor flooding - new problem found

Post by CRAFFS » Thu Aug 08, 2019 7:34 am

I followed DenverWinger's (sensible) advice (see post 6 August) to disconnect/plug the vacuum line connected to the petcock (also known as the "auto fuel valve"), started the engine to run the carbs dry. Now, the purpose of the petcock is to regulate fuel flow to the carbs. Great was my surprise when fuel again streamed out of the carb overflow line! The petcock (with the vacuum line disconnected) is supposed to "block" fuel flow to the carbs. My first reaction was that the petcock is leaking (e.g. broken diaphragm(s)). I stripped the petcock and inspected the sealing and actuator diaphragms and found them to be in good condition (flexible, no perforations etc.) Made sure I re-assembled everything correct and connected only the fuel line from the tank to the petcock (vacuum line disconnected & plugged). Fitted a piece of fuel hose to the exit side of the petcock (to collect fuel in a container if needed). Started the engine and.... a stream of fuel from the exit hose!!!??? - as if there is no petcock in line!!.
Now (apology for the long story), a week ago I fitted a new fuel pump (CARTER P72190 and strainer CARTER STS-8). Quite a few members on the forum recommended these components and apparently it works perfect. I am now at a loss. Any ideas will be welcomed. Thanks, Johann

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Thu Aug 08, 2019 8:25 am

I refer to my post a few minutes ago; - I just now tested the CARTER P72190 fuel pump "delivery". The delivery is 2100cc per minute compared to the w/shop manual 641cc specification. Although the CARTER pump delivers +/- 3.2 times higher than spec, it is still "classified" as a low pressure pump and is used by many members without any problems. Help!

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Re: Carburetor flooding

Post by DenverWinger » Thu Aug 08, 2019 6:05 pm

A pump can output a high volume of fuel and still not be able to develop significant pressure (a low pressure pump) but this one sounds like it's overpressuring the petcock valve and carb needle valves.

Hm...

Might have to add a pressure regulator? Do you have a gauge that can measure the static pressure developed at the pump output? Auto parts store may have a loaner gauge....
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

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CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Fri Aug 09, 2019 5:12 am

Good day DenverWinger, thanks a lot for your reply. Yes, it is clear that the pump is over-pressuring the petcock valve.
Today is a public holiday in South Africa so I will only be able to borrow a gauge (to measure pump static pressure) on Monday.

Regarding the fitting of a pressure regulator: - 1) There is not much space to fit a regulator in the fuel line between tank & petcock but I will manage something (I found an "inline regulator" on Google that is actually a bit shorter and smaller in diameter than the size of the GL1500 fuel filter).

Questions: - a) By "reducing" the fuel flow/pressure from the fuel pump to the petcock, will that not cause "stress"/damage to the pump? b) I have read that a "return line" can be fitted to the fuel system. Unfortunately the description is very vague but it seems that there are pressure regulators that "bleed" excessive fuel back to the tank. Do you have any info about this? Thanks, Johann

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Re: Carburetor flooding

Post by DenverWinger » Fri Aug 09, 2019 5:52 am

The OEM pumps have to be tolerant of no flow... at idle the pump is running but fuel consumed at idle is negligible if at all. Pump has to provide good flow at heavy acceleration and maintain a static pressure with little or no flow at idle. If other GL riders are using this pump it should be tolerant of no flow. Maybe an e-mail to the manufacturer?

I don't think the OEM pumps can be stalled, think they are impeller drive, the motor continues to run and turn the impeller but in a no-flow condition the fuel in the impeller drive will just cavitate.

A pressure regulator with a return line are such that they maintain the desired static pressure at the output, bleeding off any flow that would be above the static pressure back to the tank.

As to a fuel return line, you'd have to adapt another hose fitting to the tank somewhere for the return fuel to connect. And you'd probably hear a lot of "splashing" if the fuel return port was high up on the tank but the fuel was low... :lol: Fuel return sounds like a good idea, but probably not needed or worth the effort.

Maybe you could fit the regulator in the fuel filler area along with the petcock valve? There is a little bit of room in there...

Just now had this idea :idea: Alternatively, if the regulator is submersible it could go inside the tank along with the pump. Solves the fuel return problem, too, if it is that type. Short return hose to the bottom of the tank to stop "Spashing". Don't see why you couldn't do that, it has fuel inside it, why not outside it too?
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Sat Aug 10, 2019 9:08 am

I could not find an e-mail address for CARTER, only telephone numbers (will be quite expensive to call them from South Africa). So, I send an e-mail to RockAuto from whom I bought the pump. Their reply was that "we do not staff mechanics to answer your question" (??).

Anyway, Monday I will contact a local "auto tuner". This guy is quite known for tuning/modifying carburetor engines.

I checked and yes, will be able to fit a pressure regulator between the fuel tank outlet & fuel filter. I also like your idea of fitting the regulator in the tank. Will discuss this with the "auto tuner" on Monday (according to local parts suppliers the regulators they stock has "plastic" outer casings & adjustment buttons that is not fuel resistant...)

Thanks for all your input, will update you on progress.

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DenverWinger
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Re: Carburetor flooding

Post by DenverWinger » Sat Aug 10, 2019 9:45 am

Found you an Email address for Carter Tech Support - Perhaps this web page is not reachable from SA.... The Email address link resolves to "Techline@trico-group.com"


♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Mon Aug 12, 2019 5:02 am

DenverWinger, thank you for the CARTER email address. I sent them an e-mail, it went through, so let's see what they reply.

I just now came back from the "auto tuner". According to him, fitting a pressure regulator should solve the problem. He does not use CARTER products (not available in SA) and recommend I contact CARTER (which I did) just to get their "blessing". He mentioned that "some" fuel pumps are "sensitive" to flow "restriction" or pressure regulators in which case a regulator with return flow should be fitted.

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Re: Carburetor flooding

Post by DenverWinger » Mon Aug 12, 2019 6:01 am

Still be a good idea to see if you can find a low-pressure gauge (not for fuel injection) so you know for sure what you are working with. Likely it will be needed again to dial-in a pressure regulator.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Tue Aug 13, 2019 5:30 am

We did the fuel pump (CARTER P72190) pressure test yesterday with a low-pressure gauge and got a reading of 2.4psi

I searched for hours on Internet and at last found an article on what the required fuel pressure for the GL1500 should be (1.0 - 1.5psi). As you may know, our workshop manual only gives "a minimum flow of 640cc per minute". The flow test I did showed 2,100cc per minute.

I have received the following reply from CARTER: -

The CARTER P72190 fuel pump is low pressure, but is not internally regulated.
P72190 1.3-2.1 psi 15gph@1psi 2amp@4psi 4 psi Max

On my question "which pressure regulator would you recommend to use with the P72190 fuel pump" their reply was: -

The CARTER 404-501HP is our lowest pressure regulator at 1- 6 psi adjustable.

This was exiting news and I started searching for suppliers (I can not order directly from CARTER). There are quite a few suppliers but to my disappointment, those I contacted (Summitracing, Jegs, ebay, Sixityauto, etc.) specify the CARTER 404-501HP to regulate between 5.5 - 9psi !!! So, I am back in the woods!! :(((

Will have a coffee now and then start searching for other makes of pressure regulators that suit our requirements.

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ct1500
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Re: Carburetor flooding

Post by ct1500 » Tue Aug 13, 2019 2:56 pm

Whoa now. Normal fuel pressure for the 1500 is 1.5psi, others have used that non OEM pump and have not had flooding afterwards. Even if it were 4psi or so, healthy carbs can handle that. Remember your ride sat for three years, check your float and float valves first before going way off track with this pressure regulator thing. Test your fuel pressure first.

The internal spring is what closes the petcock valve, 3 or 4 psi fuel pressure from an aftermarket pump will overcome that spring keeping open the petcock and is to be expected. Most 1500's will continue to run and can idle all day long when vacuum line is disconnected because the 1.5psi fuel pressure is enough to keep it from closing completely, at 4psi no vacuum needed at all most likely. Classic symptoms of a failed petcock vacuum diaphragm is cutting out at high speed, example of fuel pump pressure overcoming spring tension yet not fully open thus reducing flow. Shut the engine down removing pump psi and valve closes completely. The only guaranteed time petcock is fully closed is engine off with no fuel pressure and no vacuum signal and is as designed.
Local and need repair help with your 1500, Valkyrie or ST please click contact
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Re: Carburetor flooding

Post by CRAFFS » Wed Aug 14, 2019 10:37 am

ct1500!, thank you very much for your advice and explanations, it all make sense!

To be honest, I was looking for "short-cut" advice to stop the flooding without removing the carbs (I have rather big front paws and after watching videos/reading articles regarding the carb removal, I did not feel confident doing this myself).

So, after reading your comments, I first followed a "tip" DenverWinger posted (disconnect fuel flow to the carbs, start the engine and run the carbs out of fuel - hopefully the floats will "drop" (if it was stuck). Then connect the fuel pump, start the engine and with the "sudden rush" of fuel to the fuel chambers, the needle & seats will hopefully open (if it was stuck). I repeated the process and whalla!, no more flooding!! The engine idles smoothly and after a few minutes (to warm up) I revved the engine a bit and then a bit more. It picked up "cleanly" with no hesitation or stutter. Took a short break and started the engine again. It fired up at the touch of the button, runs so sweet! Will now double check that all connections & fittings are nice & tight and then start putting all components & body plastics back. Very excited and happy although I must be realistic in that the carbs might have blocked jets etc. and will have to be removed at some stage.

Again, thank you for your time and explanations. One very important thing I have learned from you is that "The only guaranteed time petcock is fully closed is engine off with no fuel pressure and no vacuum signal and is as designed". Thanks again.

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Re: Carburetor flooding

Post by DenverWinger » Wed Aug 14, 2019 6:30 pm

Glad to hear that the little trick did the job! Good Show! :D
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

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Re: Carburetor flooding

Post by CRAFFS » Thu Aug 15, 2019 3:43 am

DenverWinger, yes, I am so thankful for all your help and the time spent to "assist" me, I really appreciate! Learned a lot during the process.

Winter here in Cape Town but today nice sunny day. Busy carrying all body panels (plastics) outdoors for a proper wash before putting it back.

Will take the old girl for a short/slow run and then start with maintenance jobs (engine/diff oil changes, brakes, cooling fluid etc, etc.) and checking all "systems". So don't be surprised when I am back with more questions!

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Re: Carburetor flooding

Post by SG_Jay » Thu Aug 15, 2019 12:11 pm

Now that you fuel flowing correctly, it would be good to start running some seafoam through those carbs to get rid of any leftover gunk that may be lurking. Maybe run a half can with your next 2 fill ups.

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Sat Aug 17, 2019 5:51 am

Hi SG_Jay,

Thanks for your advice. I have read quite a few very positive articles about Seafoam. We don't have a product called "Seafoam" down here in South Africa although we have quite a choice of carburetor cleaners (all with different "active ingredients"). Any change you would know what ingredients are in Seafoam? With that info I can hopefully find something similar here. Thanks a lot

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Re: Carburetor flooding

Post by SG_Jay » Sat Aug 17, 2019 8:26 am

I'm sure there are products available that do the same thing. There are some that make their own home brew version of seafoam. Maybe that will help. Here's a link to one
https://www.instructables.com/id/Homema ... -Knockoff/

CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Sun Aug 18, 2019 5:48 am

Thanks a lot SG_Jay,

I will check for a similar product on Monday.

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Re: Carburetor flooding

Post by GBKid » Sun Sep 01, 2019 5:51 am

Adding a good carburetor cleaner a couple times a year to keep them clean, not only when a problem arises, is a good idea. I don’t know if the Quicksilver brand carburetor cleaner is sold in South Africa, but I found it to be the most effective (it is the yellow bottle on the right). Also, adding Marvel Mystery Oil (red bottle in middle) to your fuel a few times a year can’t hurt either. It can be used as a “fuel additive, oil additive, corrosion inhibitor, penetrating oil, and transmission leak stopper and seal relubricator” according to the manufacturer. I only use it in my fuel a couple times a year to clean out gum and varnish in the upper engine. The Star Tron fuel cleaner on the left in the blue bottle is also effective. Hopefully some of these products are sold where you live. But in any event, it sounds like your problem will be solved with just a good fuel cleaner. Happy Trails!



CRAFFS
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Re: Carburetor flooding

Post by CRAFFS » Mon Sep 02, 2019 3:19 am

Hi GBKid, thanks a lot for the info!. None of the products you listed are available in South Africa. The "better" known products here are Wynns & Spanjaard plus a few other (much) cheaper products.

I tried the Wynns "add to fuel in the tank" product and took the bike on a +/- 50Km run. It does run better but still some "hesitation" when accelerating from low RPM (between 2000 & 3000). I repeated the process and did another run but no further improvement. On Friday I tried the Spanjaard Carb Cleaner. The engine must be at running temperature. This product is in a spray can and are used as follows; - Disconnect the fuel pump, start the engine and run the carburetors "dry". Disconnect the fuel hose between the petcock and carb float chambers (on the petcock side). Spray the carb cleaner into the hose until the float chambers are "full". This takes a while as one needs to spray a little bit at a time to "displace the air" in the float chambers until full. Wait for 20 minutes, reconnect the fuel pump and petcock hose and start the engine. The engine ran a bit rough in the beginning (keep the engine at +/-1500RPM). After a while (+/- 2-3 minutes) the engine idled smoothly and revved without "hesitation" (I am quite optimistic!). Unfortunately it was raining all weekend and I did not take the bike for a run. Nice weather today and I am quite excited to go for a run later today. Will post later today!



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