Lineslinger
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- Joined
- Feb 26, 2017
- Messages
- 1,781
The length of the post is necessary for full description.
I need some ideas on what to try next for my 74' 850.
The bike runs great. I mean great, just pulls and pulls. I have been scolded by the police twice to back off. I think they give me a break because I am an official "old timer".
But, after a few hours, the plugs, once again, begin to foul. I have been dealing with this condition since I installed the carbs after the original overhaul. I have taken them down multiple times since to confirm all the components are in place, the floats are set and jets are clear and working...I'm confident the internals are correct.
I have installed the new hardened slides, needles and guides, floats and needles, fuel screens/filters, clean idle circuits. I run a K&N air filter, the intake and carb fasteners are tight, no air leaks. The intake manifolds have insulating spacers/gaskets in place, no gas leaks, etc. etc. etc.
There is a new Tri-Spark EI installed and timed out with a degree wheel...28 degrees BTDC. It is performing flawlessly.
I put in hotter plugs I got from Danno, changing from NGK BPR-7ES to Champion N-4G's which helped in terms of a cleaner burning plug but these too eventually foul. This might be an indication of what? Advance the timing a few more degrees?
The wet sumping is almost non-existent but I drain the case anyway, just takes a couple of minutes so WGAS.
When the engine is warm it usually fires first kick and if it won't fire from the 3rd kick on I know exactly where to look, spark plugs.
Fouled. As in Black.
I have really worked at tweaking the 932's for optimal performance and if I take them any further to the lean side performance suffers and idle falters along with all the popping and backfire racket....and yet the plugs still foul.
I try not to let it sit and idle for too long...but traffic conditions are not always conducive to this and I don't do too much long ride/highway riding...today's drivers are idiots. Could these fouled plugs simply be reflecting my recent riding style?
I'm really considering a new set of Amals but after spending a bunch of money on rebuild components I am really reluctant to do so...plus I did a good job on the rebuild/overhaul and I want the original carburetors on the bike. There is zero assurance that after dropping more money on new carbs this is the route to solving the issue (although I bet it will) so that gnaws on me as well.
Any ideas on where to dig next are certainly welcome.
I need some ideas on what to try next for my 74' 850.
The bike runs great. I mean great, just pulls and pulls. I have been scolded by the police twice to back off. I think they give me a break because I am an official "old timer".
But, after a few hours, the plugs, once again, begin to foul. I have been dealing with this condition since I installed the carbs after the original overhaul. I have taken them down multiple times since to confirm all the components are in place, the floats are set and jets are clear and working...I'm confident the internals are correct.
I have installed the new hardened slides, needles and guides, floats and needles, fuel screens/filters, clean idle circuits. I run a K&N air filter, the intake and carb fasteners are tight, no air leaks. The intake manifolds have insulating spacers/gaskets in place, no gas leaks, etc. etc. etc.
There is a new Tri-Spark EI installed and timed out with a degree wheel...28 degrees BTDC. It is performing flawlessly.
I put in hotter plugs I got from Danno, changing from NGK BPR-7ES to Champion N-4G's which helped in terms of a cleaner burning plug but these too eventually foul. This might be an indication of what? Advance the timing a few more degrees?
The wet sumping is almost non-existent but I drain the case anyway, just takes a couple of minutes so WGAS.
When the engine is warm it usually fires first kick and if it won't fire from the 3rd kick on I know exactly where to look, spark plugs.
Fouled. As in Black.
I have really worked at tweaking the 932's for optimal performance and if I take them any further to the lean side performance suffers and idle falters along with all the popping and backfire racket....and yet the plugs still foul.
I try not to let it sit and idle for too long...but traffic conditions are not always conducive to this and I don't do too much long ride/highway riding...today's drivers are idiots. Could these fouled plugs simply be reflecting my recent riding style?
I'm really considering a new set of Amals but after spending a bunch of money on rebuild components I am really reluctant to do so...plus I did a good job on the rebuild/overhaul and I want the original carburetors on the bike. There is zero assurance that after dropping more money on new carbs this is the route to solving the issue (although I bet it will) so that gnaws on me as well.
Any ideas on where to dig next are certainly welcome.