Plug color wont change fast enough to pin point a intermittent fuel problem.

I kreamed my tank on the first FL350 but still ended up getting a new tank anyways, it was never quite right.

if its a new carb either a part would have to be missing or the body cracked to cause these problems. Its easy to let your thoughts run wild with all the unknown possibilities but really there are not too many thing that can go wrong.

If there is a "next time" I would use a totally separate clean, gravity fed fuel source, ie temp gas tank hanging from frame, pinch or plug the pluse tube, i would clean the carb and pull then look thru each jet and the float vavle. Take a peek at the reeds to make sure they are good. Once that is done and you can be sure you have a good fuel system.

When you fire it up check for air/vacuum leaks by running propane around any possible leak areas, intake, case halves, carb, head, main seal, every where. For my rig I use a small bottle of propane like for a torch and rig up a very small diameter hose, i use a hose then 1/4" copper tubing 12" long and smash the end for a nozzle effect, i can bend and stick it in all the cracks and corners. Sometimes an air leak will only happen when warm.

I don't think it is an air leak. When the motor (( Internal Combustion Engine ? )) was assembeled (both times) I used yamabond on the base gasket, reed gaskets, and exhaust gasket. I replaced the reeds this build with boysen reeds, did a leak test on the bench, all checked out ok. I popped the head off yesterday, all looks good still, no scoring at all, piston top looks good, bore is still fresh with cross-hatching. But like Hoser said, if it is an intermittant problem (like it is) then you cant really go by the looks of the plug/piston/etc... I am pretty sure it is the carb running out of fuel, I ran the bike during spring break bone stock and did not have this probem. It all started after I put on this carb. When it was shipped, it had the wrong main jet, and it was MISSING the pilot jet! Ticked me off pretty good.
Anyway, I am going to toss the stock carb and exhaust on today, jet it up a bit, MAYBE putt it around to see if it clears up the problem, and go from there.

Pulled the top end back off again. Rusty (shoubadaba) bet me a base gasket that the rings were siezed into the piston again. Looks like he owes me a base gasket, rings, piston, and cylinder all looked fine. Going to drop the stock exhaust and carb back on tomorrow. Also, plug looked fouled which would have caused the cutting out. Still want to go back to stock for now though, I don't want the wife's ody faster than mine!

wrench, wrench, wrench away. The joys of owning a 23 year old bike!

Sucker oh well its only money SHHHHHHHHHHHH don't tell my wife.

I have a couple of thought. By chance has it had a blown haed gasket latly. If so you my have twisted the crank a little. I know in the past when I found that after a haed gasket replacment and it would not rev. It was a twisted crank. If every thing els is right and it just started at the sand dunes with paddles. Did it land hard on the gas. rember theres no clutches in the tranny. The wifes bike right. Just a thouoght. Have you had a rod rebuild done on this crank? If you put all stock stuff back on and still don't rev. Time to do run out on crank. Run out should be done every time a rebuild is done and this may be why and a spot weld may be in order. I hope it not and hope I"am all wet. Ask around.

Good thought but shouldn't he be able to check the timing to see if the crank twisted, I never had a twisted crank so never got to play with this idea..

The funny thing about the problem is it will rev out for a bit then just starts to bog after a little while. The Engine has never blown the head gasket. Timing is perfect ,crank specs out. I think its either the carb since it has bogged since day one with the new carb,or something to do with the magnito. If the problem persist with the stock carb then the only thing left is the magnito assembly since everything else has been changed.

Have you checked the stator-CDI with a meter to see if goes in specs ?
it will heat up and lose spark-thus causing the issue.Battery is good as well, no bad cells in it?IS IS only having the issue when hot?try removing the gas cap when this happens and see if it will run then.
What exactly are you running when it happend-still at 3/4 throttle and then it bogs down-or does it blubber and not pull through at all-have you adjusted from the bottom up on the carb after each rebuild-any little pice of crap on the needle will drive you nuts-ask Hoser.

http://www.pilotodyssey.com/PO/view ... sc&start=0

Had same issue-this is what we came up with here-have you ever had a issue with the wire harness-did on the last ride ou went on perhaps run over something to damage the harness in a spot?

Yea if it was twisted or gear was off a tooth it would not rev out at all. Mud is right about heat and electronics. I thought you changed CDI (Capacitor Discharge Ignition) thu. what about the battery. Or stator. You could put his motor (( Internal Combustion Engine ? )) in your bike to see if its in the motor (( Internal Combustion Engine ? )) or bike wiring. Wierd for sure I hope the stock set up works if it does destroy the faluty parts to keep out of circulation. Um

I would bet he checked his carb vent lines for blockedge.

All the electronics have been replaced, Coil, CDI (Capacitor Discharge Ignition). Just not anything internal, stator or magnito. As for the carb it has been adjusted from top to bottom still the same problem. As for the tank it has a breather where the return line is suppose to be since its running a mikuni which requires no T or return line just the fuel line directly to the carb. So all points to carb or intrenal electronics.

Give this a read? Mudbogger found he had a bad harness
http://www.pilotodyssey.com/PO/viewtopic.php?t=4827

This is a very interesting problem, to say the least. You guys have tried everything I can think of, except swapping the plug??? You will start loosing spark at the highest revs first. I have chased my tail with a very similar problem years ago. (KISS) lol

To have a twisted crank, you would have to of had a pretty severe seizure/lock up at a high RPM. Never heard of one in a 350 or 400, but I guess its always possible. Did you check the mark with a timing light? Should not move when revved if memory serves. One more suggestion on timing, I sheared a woodruff key on the flywheel to crank. My 420 would idle but backfired and died when I throttled up. Pain in the arse to check but I am sure you are ready to try about anything! Hang in there, we all have felt this pain before troubleshooting.

This kind of "brain storming" suggestions is one of the things I love about this board. Keeps the wheels turning in our heads.

Gary

I chased my tail on Banshee once until I found out that two of the "upgrade/replacement" CDI (Capacitor Discharge Ignition) boxes were bad... I would take the known-good parts from your other Ody and do a systematic replacement. Have you done the carb swap yet?

that's what was done we swaped the CDI (Capacitor Discharge Ignition),coil, and rectifier from the other fl350 and its running those now. He just got the new gaskets today (since we pulled the cylinder again to check for stuck rings) so he will be reassembling this weekend with all the stock stuff, Pipe ,carb and such.

Yup, got the ody back to stock except for the exhaust. Forgot there was a hole drilled for an EGT guage when I had that exhaust on my other ody. No biggie, just left the aftermarket exhaust on. Got the stock carb, air box, new plug, fires up and idles pretty good. We shall see how it runs in Glamis for the "east meets west" trip. Not too concerned this time since it wont be a primary riding vehicle, am bringing plenty of other toys to ride just in case.