General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: Buz on June 01, 2018, 08:09:38 AM

Title: 1993 FJ1200A Idle issues
Post by: Buz on June 01, 2018, 08:09:38 AM

Buz here. Newby. Found a 93 FJ1200A (ABS) with 12K miles. Really nice and clean. Clean Givi Hard Cases, Progressive fork springs, Corbin seat and K&N air filter otherwise stock.

Above 2k runs like a freight train. Will not idle. Way lean. Plugs tan brown indicating lean. Pulled carbs. Have stock 155 air and 37.5 fuel jets in idle circuit. Idle fuel jets were clogged. Air jets good. Float bowl surprisingly clean. One mixture screw totally trashed. Will have to extract it somehow. Maybe have to replace. Other 3 mixture screws, springs, washers and O-rings good. Will clean the mixture circuits parts and put all back together.

Question: Given a K&N air filter, should that alone push me up to a larger Idle fuel jet? Say a 40 or 42? Also, living in Atlanta, should I go to a cooler spark plug?

Thx for the help. Have already learned a lot from this site. E.G. I dropped the rear frame section to ease in air filter housing removal. Also, before dis-assembly, with engine running, did the spray test for air leaks. Found none.

Again, many thanks.

PS: Any Atlanta FJ members active?