Backfiring; please help diagnose


Information and questions on GL1500 Goldwings (1988-2000)
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ActionMatthew
Posts: 17
Joined: Wed Jun 05, 2019 11:58 pm
Location: Wasilla, Alaska
Motorcycle: 1997 GL1500SE

Backfiring; please help diagnose

Post by ActionMatthew »



Hello everyone! I got my GL1500 (1997) all back together today and all is well except, there's a backfire under a load or when I let off the throttle, and it feels like it is hesitating a bit (not as strong as usual). The history is that I bought this bike about a year and a half ago and proceeded to get pretty deep into it. The rear master cylinder for the rear brake had to be rebuilt, so I did that. I also put new timing belts in, new plugs, new air filter, new lights, brake pads front and rear, and some other minor parts (fuel filter). I had to take the collector box off to do the master cylinder, so that meant taking the right hand side exhaust manifold off, so new crush gaskets when I reinstalled that.

I started it after I put the new timing belts on, and it ran just fine. But, today, after I put everything back together, it started right up, but there was an obvious backfire, and I can hear it in the carb too, just not as often. I took it for a ride too, about 5 miles, and the backfire remained. I can rev it and hold it smooth but as soon as I let off the throttle I get pop pop pop. And when I'm loading it up, the motor/carb seems to hesitate/stutter slightly. The fuel in this is probably going on close to 2 years old, but I did add some stabil. I'm thinking I need to start over and check timing belts, but I followed the guidelines step by step and the timing marks were on point.

Before I get into starting over with the timing belts, is there anything more "low hanging fruit" that you'd look into? I have a gut feeling that I did the timing without changing a thing, but I need to get going on this and thats my theory right now.

Thanks you all!

Matthew



User avatar
DenverWinger
Posts: 1537
Joined: Thu Jun 23, 2011 2:20 pm
Location: Denver, CO
Motorcycle: (s)
1980 GL1100 STD Vetter (2005-)
1993 GL1500 Aspencade (2017-)
1983 Trav-Lite Camper (2010-)
Past rides
1972 CL350 (1980-1988) sold
1978 Suzuki GS550 (1985-2005) sold
1977 GL1000 (2002-2006) sold

Re: Backfiring; please help diagnose

Post by DenverWinger »

You say you put in new sparkplugs? I'd bet you crossed a couple plug wires....
♫ 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

ActionMatthew
Posts: 17
Joined: Wed Jun 05, 2019 11:58 pm
Location: Wasilla, Alaska
Motorcycle: 1997 GL1500SE

Re: Backfiring; please help diagnose

Post by ActionMatthew »

I did put new plugs in, and I'll go look at the wires, but if I remember correctly the wires are fairly well designated. I'll check that though, anything is better than going back through to the timing (which I swear, looked perfect when I buttoned that up, and the pulleys did not move...).

Thank you.

Any other ideas?

ActionMatthew
Posts: 17
Joined: Wed Jun 05, 2019 11:58 pm
Location: Wasilla, Alaska
Motorcycle: 1997 GL1500SE

Re: Backfiring; please help diagnose

Post by ActionMatthew »

Mark, you were right! I had crossed two wires on the lh side. Made those 'great' again, and it was an :D :D instant difference. Good to be back on the road! I REALLY appreciate your help!

User avatar
DenverWinger
Posts: 1537
Joined: Thu Jun 23, 2011 2:20 pm
Location: Denver, CO
Motorcycle: (s)
1980 GL1100 STD Vetter (2005-)
1993 GL1500 Aspencade (2017-)
1983 Trav-Lite Camper (2010-)
Past rides
1972 CL350 (1980-1988) sold
1978 Suzuki GS550 (1985-2005) sold
1977 GL1000 (2002-2006) sold

Re: Backfiring; please help diagnose

Post by DenverWinger »

Glad to hear it was that simple :)


♫ 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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