72 cb350. Long journey of chasing carb and electrical/timing settings to get rid of a little balky "pop" that comes at 1/8 throttle, between 5-6K rpm. Having tried different pilots, mains, needles, needle settings, air screw turns, and even slides, with no success, I turned to electrical. Recognizing a wonky advancer and compensating for it, the problem remains. Points, Coils and condenser, caps are newer. (all changed in last few years, with very little miles on them)
From what I've read, I've thought it was a lean pop; either because of jetting or advanced timing. (no leaks, and doesn't give symptoms of leaks.) But having turned things crazy rich in the past, hasn't solved the problem.
So as a stretch, I come to my shady exhaust system. PO seems to have cut an inch or so off the headers. These are connected with expanders to cheapo 12" mufflers. I've noticed when running Seafoam, that some of the smoke show came out of the joint between the headers and mufflers. I've since tried sealing those gaps with red RTV.
People write about the necessary length of the exhaust, and how short pipes wreck performance. I've read about the exhaust pulses, and how if the pulse doesn't clear out the cylinder, it will "8 stroke". Does that sound like what's happening on my bike? It's almost like a little pop and a misfire. Like an intermittent stutter.
Is there anything I can try in the quick short term, to see if this is my problem, and to do a quick fix? I postponed my motorcycle test last year because the bike didn't feel reliable, but it's coming up next week and isn't postponable any further. Was planning on taking off the exhaust right to the gaskets, and making sure it's all sealed up. (I've done it before, gaskets are new.) Any suggestions besides "get a new exhaust" would be awesome. Live in a small town and just checked craigslist for the nearest 100 miles. Nothing in the area.
Thanks a ton,
John
From what I've read, I've thought it was a lean pop; either because of jetting or advanced timing. (no leaks, and doesn't give symptoms of leaks.) But having turned things crazy rich in the past, hasn't solved the problem.
So as a stretch, I come to my shady exhaust system. PO seems to have cut an inch or so off the headers. These are connected with expanders to cheapo 12" mufflers. I've noticed when running Seafoam, that some of the smoke show came out of the joint between the headers and mufflers. I've since tried sealing those gaps with red RTV.
People write about the necessary length of the exhaust, and how short pipes wreck performance. I've read about the exhaust pulses, and how if the pulse doesn't clear out the cylinder, it will "8 stroke". Does that sound like what's happening on my bike? It's almost like a little pop and a misfire. Like an intermittent stutter.
Is there anything I can try in the quick short term, to see if this is my problem, and to do a quick fix? I postponed my motorcycle test last year because the bike didn't feel reliable, but it's coming up next week and isn't postponable any further. Was planning on taking off the exhaust right to the gaskets, and making sure it's all sealed up. (I've done it before, gaskets are new.) Any suggestions besides "get a new exhaust" would be awesome. Live in a small town and just checked craigslist for the nearest 100 miles. Nothing in the area.
Thanks a ton,
John