Resurrecting a 1500, cant get life

[Easter]

OK, long intro. I am not familiar with 1500 but have quite a bit of experience with the four cylinder GL's. This bike was not running when acquired and had set for several years I do not know why it was parked but several plastic covers had been removed. Engine turns freely, has acceptable compression, has spark on all six plugs (original plugs but have checked several and seem ok) I pulled the carbs (lots of fun!!!) and cleaned them in ultrasonic cleaner and replaced some but not all of the o rings. I believe all the passages are clear and I spent a day or two re-attaching the 19+ vacuum lines. My goal with this bike was to strip it to the basics and perhaps eventually build it into a reverse trike. But first get it to run.

It spins but will not show any sign of life when I attempt to start it using both gasoline and ether. Things I have tried: on center stand, side stand up. Kill switch on. Clutch wired to handle bar (just to be sure). removed belt cover and confirmed correct position of pulleys/belts. Timing light indicates correct timing. (at all three timing marks).

I didn't expect it to run perfectly on start up but I did expect at least some signs of life. I do occasionally get a back fire with the ether but even that is seldom. I have not installed the air box and the vacuum lines are not going anywhere at the moment.

I am out of ideas.???

[Charlie1Horse]

First, make sure that you have a well charged good battery. These 1500s won't have enough power to spin over and fire the coils if the cranking power is below, I think, 10.5 volts. Next, I would check the fuel pump for operation. When you turn the key on you should hear the pump run for a couple of seconds. Pull the fuel hose off the vacuum operated petcock and see if the pump will produce fuel into a container/bucket. If there is fuel from the pump, check the petcock (it's right in front of the gas filler cap) to see if there is fuel through it to the carbs. You must have vacuum to the petcock's small port/hose to open the valve to let fuel through. Use a hand vacuum pump there. If there is fuel to the carbs, and you have spark, sounds like it should start up. My 92 GL Interstate would not start and would backfire something like you are talking about and my problem was a bad ignition coil. Check the four pin plug on the right side near the engine control module that gives power to the coils. If one of the three coils is bad, like mine it would act like that. Do the check as per the OEM shop manual. You may only have spark on four plugs instead of all six. Each coil fires two plugs. That's where I would start.
Russell

If I don't do Facebook or Twitter, do I still have to do Social Media Distancing???

[bluthundr31]

I'd like to add one small caveat to the advice from Charlie1Horse, , , , the '88 & '89 would run the fuel pump for a few seconds as soon as the key was turned to the "ON" position BUT the fuel pump on the '90-'00's would only run once the "start" button is pushed and the key in the "ON" position. Since the OP didn't state what year the bike is, I'd check that first to make sure to rule-out the fuel pump.

Fuel, Air, and spark should be confirmed first to get 'er to fire up.

[Swagonmaster]

I will take a real long shot, check the compression, if you have fire and using a timing light makes me think that you do (although checking fire at all 6 would be a good idea) and have shot fuel down the carbs it should fire. While you are at it make sure that mice haven't built a nest in the exhaust and stopped it up.

[Easter]

Thanks guys for taking the time to respond. Can't be the fuel pump because there isn't one! At this stage I am fueling from an overhead bottle direct to carb fuel lines after the petcock vacuum valve. But it should at least cough from the ether anyway. Haven't looked for mice nests but will do so. As stated compression is acceptable at all six cylinders and I have spark at the plug end of all plug wires. At the moment I am using a 12 volt truck battery setting on the passenger foot rest and although it isn't much of a battery, when it is combined with a 50 amp boost it spins the engine quite well.

Still stumped at lack of response from the engine. Oh, and it is an '89

[Swagonmaster]

As Artie Johnson used to say "verrry interesting but not very funny" (guess I'm sort of dating myself there). There is nothing like one that "can't do that!" to make you want to grab a beer or three and sit down and look at it and really think. If nothing else you get some beer and rest.

[Easter]

Pipes are clear as far as I can reach with a coat hanger. I put in an order for six new spark plugs in hopes that a hotter or more consistent spark will help. So it will be a few days before I can test that out.

[Swagonmaster]

You can do that today, pull the plug wires off of the plugs just enough to cause a gap for the spark to have to jump, instant flamethrower plugs.

[Rambozo]

Check voltage at the ECU while cranking. Often that is why a 1500 won't start. It needs to be over 10.5 to 11 volts for reliable starts.
If you checked for spark with all the plugs out, there is no real load on the starter to pull the voltage down.

[Charlie1Horse]

My next idea would be to do a check of the ignition coils. with a digital ohm meter check resistance through the coils from the spark plug caps, 1 & 2, 3 & 4, 5 & 6, as per the OEM service manual. Then check resistance through the primary winding of each coil. My 92 GL1500 Interstate got to the point where it was very hard to start in the morning. The #3 ignition coil being the worst was still giving off a seemingly good spark but, was getting old and weak. I would crank for about ten minutes and at first, no sign of life. But after a few minutes I would start getting popping and backfiring, and occasional 'try to run but only sounded like maybe it would start up'. This was with a new AGM fully charged battery. I would run it almost dead and then jump it off with my truck. After a few more minutes and a few more backfires it would start and run pretty well. After that first start of the day it would start up with just a touch of the starter. A couple of weeks later as I was on a Patriot Guard Mission, I lost two cylinders, # 5 & 6, only running on 4 cylinders to return to the house.i did the ignition coil test and found the primary test on the #3 coil failed. I replaced all three coils with OEM coils and new OEM plug wires and never had any more trouble. It only is a little hard to start first start of the day after sitting for several weeks. If you have (1) Air, (2) Fuel, and (3) Spark properly timed, or close, it should run. So I would check the coils. Hope this helps.
Russell

If I don't do Facebook or Twitter do I still have to do Social Media Distancing???

[Easter]

Ok making a little headway. It is alive and will run briefly on ether or fuel directly in the carb venturi but not from an overhead bottle straight into the fuel lines at the carb . Sounds good while running for those few seconds, and responds to the throttle.

While the carb has all twenty vacuum lines, none of them are connected to anything yet, is it possible that some of the air circuits are keeping it from accepting fuel (it will draw a tiny bit in while running but not enough to keep running). I am simply trying to get it to run with the absolute minimum of external technology and to strip it of all the extra Goldwing goodies.Think rat bike.

[Swagonmaster]

You might check that the fuel pump is putting out some fuel, it's under several psi of pressure and that might make a difference.

[ct1500]

While the carb has all twenty vacuum lines, none of them are connected to anything yet, is it possible that some of the air circuits are keeping it from accepting fuel (it will draw a tiny bit in while running but not enough to keep running). I am simply trying to get it to run with the absolute minimum of external technology and to strip it of all the extra Goldwing goodies.

Well Ya, they make a difference as some pull manifold and others venturi/carb circuit vacuum/air.