[klingonwarpath]

imported post

Hi all,

I have a strange unsolved problem with my 84 Aspencade GL1200. I am looking for ideas. I noticed earlier in this riding season that when my bike was warm (running for a while) and very low on fuel (usually less than 1/4 tank) and typically going on uphill incline, that all of the sudden it would start to loose power and seam to only be running on two cylinders. At first, I could get to level ground, and rev it a bit and it would seem to recover. It got a bit worse, and I would have to let it cool down. Also filling the tank would seem to help out right away also. It seemed like the fuel pump may have been acting up, so I replaced the fuel filter and fuel pump. It seemed to be running better and I thought the problem was cured. I then let the tank run really low (1 bar flashing) and while on the highway, the problem occured again. I was carrying afew gallons of gas in my trunk so I filled it up (which took it over 1/2 tank) and tried to fire it up again. It would not start this time. I sat there for over a half hour and finally managed to get it to run, but it still was running only on 2 cylinders. I had to nurse it back to a shop where it now sits. I ran it today and it seemed to run fine, I could not get it to act up. We thought possibly something electrical (like Pickup coils, etc..) but my mechanic mentioned that in cases where he has seen these problems, the typically will act up when the temp rises. It was not acting up today. We drained the tank to nearly empty and tried to duplicate today, but no luck. The gas exhaust did smell extremely rich and was burning our eyes when running today, so he is wondering if possibly plugs, or plug caps might be intermittantly failing. another thought was possibly something in the gas tankthat might beblocking or prohibiting the siphon effect from the gas pump...cracked or leaking sump line that can act up when very low on fuel?Not sure how this fits the thermal factor in though. I am stumped and I am curious if anyone has heard of such a strange problem.



Sorry to be long winded, but wanted to be detailed.

Thanks

Dave

 

[exavid]

imported post

I'd suggest getting some spark plug testers which are available at Harbor Freight pretty cheaply. You plug them in line with the spark plug wires and they flash when the plug fires. They are very handy to help show when the high voltage to a plug fails. That's going to be your first priority, discovering whether it's a fuel or ignition problem. I suspect failing pulser coils, but they aren't following the usual pattern. If you don't want to buy a couple plug testers you can carry a couple spare spark plugs. When the bike won't run disconnect the plugs on one bank and hook the spare plugs to the cable, laying the spark plugs on the head so the shells will be grounded. Then crank your bike to see if the plugs are still sparking. If they both spark odds are all four are since each coil fires two cylinders. Once you can either eliminate ignition as the problem or prove it's not you can move onto investigating the carbs as a cause.

 

[plainmech]

imported post

hmm sounds very familiar though on 70 model pick up, customer could drive everywhere except twin bridges in waco,tx. dadump pattern bridge, truck would die half way across, tow back to shop, run like a top. after 5-6 times pulled fuel tank found rust, driving around town worked great but dadump dadump of that bridge would allow rust to move and block outlet, tow it back rust cleared ran great. thought maybe it was posessed and couldn't cross water:cheeky1::cheeky1::cheeky1::cheeky1:. sorry to change subject but it made me think of this and i felt compelled to share. hell maybe help someone somewhere:action::waving:

 

[klingonwarpath]

imported post

Thanks for the tips and info. I am currently riding the bike and it hasn't acted up, but am keeping plugs with me to test for spark when or if it acts up again. I really believe it is some strange fuel delivery or fuel supply issue but not for sure.



Thanks again

Regards

Dave

 

[newbiker]

imported post

Pull spark plug wires and measure resistance between 2 front ones and then 2 rear ones. It should be about the same.
I found 2 coils with cracks on my Wing, so I got another coil from my shed and it had crack too! So I chose 2 coils with smaller cracks, covered cracks with RTV and installed them. Not sure if RTV can help but at least it will prevent moisture going in.