Cliff notes - old bike, recently rebuilt carbs, idles well but gets rich and stumbles when attempting to ride.
Longer version:
1990 Yamaha FZR600 w/56K on it.
Bike was driven daily until 4-5 years ago by a good friend. He parked it when he bought newer bike. Bike had dynojet stage1 carbs, k&n panel filter and full hindle exhaust.
2.5 years ago I bought it after it had sat. Took the carbs to yamaha dealer. They cleaned and 'replaced the jets which were beyond cleaning'. Sadly they didnt check what was in the carbs, so i had a mix of dynojet and yamaha oem.
Took carbs home. Local shop #1 picked up bike and carbs. They installed them, synced them up and got the bike tuned fairly well using their butt dyno. Also did safety inspection, etc. Got bike on road June 2011. I put 10K kms on it last summer.
From june -> december mileage decreased from 38mpg to about 30. Also noticeable rougher idle, and the little smoothness the bike had became much worse. Parked bike in December. Fuel stabilizer, battery minder, etc.
Got bike out in March. Drove quite well, still low 30s mpg. Some days ran fairly smooth, other days sputtery at low speeds and crappy idle.
Took bike to local shop #2 to have the carbs went through properly. Fully rebuilt with a NEW dynojet stage 1 kit. Bike ran very well on the stand using their fuel can and no air filter. They put the bike together assuming it was done. Started bogging and running very rich when trying to drive it. Removed tank and air filter, seemed much better. Put just the air box on and it ran fine still. Assumption was fuel pump was acting up. Bought used fuel pump (in good working order, tested by member of FZR forum). Improved a tiny bit, but still runs like crap when under load. Seems to rev freely when parked, but as soon as they try to test drive it or put on their dyno it sputters, bit of black smoke, and essentially drowns itself in fuel apparently.
Shop has went back through the carbs, checked all settings. Emulsion tubes look to be ok. Good seal on air box etc. Still no luck.
looking for ANY recommendations. Shop is out of ideas. This guys generally knows his stuff when it comes to tuning and carbs, but is stumped. Likely missing something obvious but doesnt know what. Looking for suggestions or ideas to try.
Please help. Between waiting for shop time, and ordering the jets/pump ive been down nearly 9 weeks. This has to get fixed asap
Longer version:
1990 Yamaha FZR600 w/56K on it.
Bike was driven daily until 4-5 years ago by a good friend. He parked it when he bought newer bike. Bike had dynojet stage1 carbs, k&n panel filter and full hindle exhaust.
2.5 years ago I bought it after it had sat. Took the carbs to yamaha dealer. They cleaned and 'replaced the jets which were beyond cleaning'. Sadly they didnt check what was in the carbs, so i had a mix of dynojet and yamaha oem.
Took carbs home. Local shop #1 picked up bike and carbs. They installed them, synced them up and got the bike tuned fairly well using their butt dyno. Also did safety inspection, etc. Got bike on road June 2011. I put 10K kms on it last summer.
From june -> december mileage decreased from 38mpg to about 30. Also noticeable rougher idle, and the little smoothness the bike had became much worse. Parked bike in December. Fuel stabilizer, battery minder, etc.
Got bike out in March. Drove quite well, still low 30s mpg. Some days ran fairly smooth, other days sputtery at low speeds and crappy idle.
Took bike to local shop #2 to have the carbs went through properly. Fully rebuilt with a NEW dynojet stage 1 kit. Bike ran very well on the stand using their fuel can and no air filter. They put the bike together assuming it was done. Started bogging and running very rich when trying to drive it. Removed tank and air filter, seemed much better. Put just the air box on and it ran fine still. Assumption was fuel pump was acting up. Bought used fuel pump (in good working order, tested by member of FZR forum). Improved a tiny bit, but still runs like crap when under load. Seems to rev freely when parked, but as soon as they try to test drive it or put on their dyno it sputters, bit of black smoke, and essentially drowns itself in fuel apparently.
Shop has went back through the carbs, checked all settings. Emulsion tubes look to be ok. Good seal on air box etc. Still no luck.
looking for ANY recommendations. Shop is out of ideas. This guys generally knows his stuff when it comes to tuning and carbs, but is stumped. Likely missing something obvious but doesnt know what. Looking for suggestions or ideas to try.
Please help. Between waiting for shop time, and ordering the jets/pump ive been down nearly 9 weeks. This has to get fixed asap
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