Kelly Corey

After settling for status quo for the remainder of 2010 and now this far into 2011, I took off the carbs again a couple of weeks ago and found the main jets were all #115. Stock should be #105 in #1 and #2 and #102.5 in #3 & #4. The jet needles are also wrong, 4CP3 in 1, 3, & 4 and 4CP7 in #2. Should be 4CP4 and 4CP6 according to Haynes. Anyway, I found some smaller main jets (thanks to J&R Cycle in Stayner!), went with #110 in #1 & #2 and 107.5 in #3 & #4. Still need the jet needles on the top clip setting, but the bog is almost completely gone. The previous owner must have tried to compensate for the 4-1 Yoshi pipe with the larger jets, but I think they way overcompensated... Just did this work this morning and ran it around for a bit on the local roads. Seems a whole bunch better in the 3/4 to full throttle range. Re-synced the carbs, will hopefully get to test it out on a longer run tomorrow if the weather holds. Getting tired of yanking the carbs, it is rough on the intake and exhaust boots, harder each time to get the all-important seal. Thinking of going for the pod filters...

Hi, I have the same bike and have been working with carb issues for part of the summer. I have made some advances this weekend, I vacuum synced the carbs using the two-bottle method, which works really well if your carbs are way off like mine were - no fluid gets sucked up! Anyway, my Haynes manual says to sync 1&2, 3&4 and then 1+2 & 3+4. The adjusting screws are super sensitive btw. My exhaust is a Yoshi 4-1-1, and I have been having issues with plugs carbon-fouling. I have it narrowed down to plugs #1 and #4; the inside plugs seem fine. I haven't been meticulous enough to see where on the throttle the fouling occurs, but I suspect it is lower range rather than upper. I have my pilot screws set to 1 turn out each right now, I have experimented as far up as 2 1/2 turns without much real difference. I have gone with a hotter plug on the outside which seemed to make a bit of difference. The bike runs well except for a stutter in 6th gear between 5500-6000 rpm. After 6000 it pulls hard and fast as far as I want it to go. I am not sure if this is an ignition issue or a carb issue, I am leaning more towards an ignition issue since it is the same coil for plugs 1 & 4 and those are the ones that are fouling. And the problem seems more rpm/engine load related rather than throttle position. I had a small leak on intake boot #2, so I took them all off and sealed them up around where the band clamp goes, some minor cracks on each. I also found that carb #2 should have a #7 jet needle, the other carbs have a #3. Someone had the #7 in carb 1, whether this makes a huge difference or not I don't know. Anyway, replaced the boots and the carbs last night, it started up fine and rev'ed smoothly. Took it for a short test down the road, runs about the best i have had it running all summer right now. I will take it out for a longer ride and come back with my findings on the stutter and plug fouling. I want to re-sync the carbs with the freshly sealed boots anyway. I found a stock exhaust for sale, I am thinking I may need to swap out the 4-1, I suspect too the carb issues I am having are somehow tied into the yoshi setup. All carbs jets are stock, and maybe I need to change the main jet to accommodate the yoshi. A lot of trouble for a 26 year old bike, but it is my first and I want it to run the best it can. It has under 26K km's and is in good shape overall. Also thinking about changing my plug boots, removing the 10k ohm stock boots with some 0 ohm boots, haven't made that leap yet.

Hi, I just picked up a really nice 1984 FJ600 with the same symptoms you are describing. It was sold to me claiming the battery needed to be replaced as it wasn't strong enough to start the bike. It could be jump started froma car battery. My bike had the carbs cleaned prior to being sold to me, and when the bike finally started there was a squeaking noice coming from the area of carb #4. The guy said the boot was a bit loose, causing the squeaking sound. I did some checking and found the manifold gasket between the carb and the head was not giving a good enough seal, presumably it was reused when the carbs were cleaned and replaced. I replaced that gasket and that noise vanished. I could detect a faint similar noise from carb #1, so I replaced that gasket too. The best part from this whole operation is that now my bike will start with the same battery, without being boosted!! My advice is to check all hoses and seals, both on the airbox side and the head side.