QuestionJim,
I recently purchased a very clean 85 FJ600 with 15k miles. The maintance records have a gap of a few years and I believe it sat for a few years. I've gone through and done a fair amount of basic maintenance to include, plugs, cut,cleaned,and re attached loose plug wire, carb rebuild,new battery, various adjustments,oil etc the bike seems very cold natured and idles poorly and wants to stall until very warm, 10 miles of hwy riding. After that it idles at about 500rpm and I need to raise it to about 1200. Where is the idle adjustment screw?
Another thing I noticed is that it has Kerker 4-1-2, with no packing at all, a K&N air box filter, and the dealer who rebuilt the carbs said a jet kit but didn't know the jet and needle sizes. Their is no sign of track use, no safety wire or drilled blots. This plus the idel suggests to me that it may have been a track bike for a few seasons. I have not checked but I am suspicious that the cam is not stock as well. I don't remember what the stock carb was but this has a 38mm body. After the bike is warm, if I run full throttle through 2nd and just into third hard on the breaks and back, about four times the bike runs great. It even spins the tire through 2nd gear which the FJ I raced stock in 84 didn't. Could the idle be related to the set-up that would explain its less than perfectly streetable ride? Thank you for any advice you can offer.
AnswerIt sounds like an idle mixture issue. Taking a look at the microfiche:
http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-fj600n-1985/o/m71...
These look like Mikuni CV carbs and the idle mixture screw is seated under a plug in a rizer which extends up near the motor side of the carb. If you are not familiar with this adjustment screw or if it is plugged let me know and I'll follow up with instructions on how to access it.
The location of the screw is indicated on image 07 here:
http://www.thegsresources.com/gs_carbrebuild.htm
