XT600rider

I had posted a week or 2 ago on my '89 XT600 that was starting & idling perfect, but cutting out/hesitating & losing power over 45mph with a load (riding). I acted on the tips from Motu and AHRMA17L, both did help! The linkage from main to secondary carbs was very off, and also the float level wasn't up to what the book showed. I corrected both, and this got rid of one symptom but I still had hesitation & banging at high speed & load. (now has power at all speeds when it didn't before!!!). It looks to me like the past owner screwed with it, not knowing how to diagnose it, and compounded the problem which I corrected thanks to you both. ANYhow; I further troubleshot the bike and found that the CDI pickup coil shows open-circuit from the neutral wire to one end. This coil is a black box with 2 small magnets that sits next to the stator in the mag cover. This now makes sense because this would cause the timing to be all off at high RPMs and load! The coil, according to the book, should read 110 ohms across both fields. One reads 780 ohms and the other 110. That is if my book is accurate. I drove my turbo-Diesel Toyota truck around town with the valve clearance BADLY misadjusted thanks to a misprint in the factory manual, so I would like to confirm whether those resistance specs (110 ohms) are correct if anyone here can verify. So now I am on eBay looking for a used good coil, as I have the feeling I won't like the price for a new one at the dealer, LOL... Comments welcome & appreciated. Thanks, Charles Los Angeles

Thanks for the tips... I'll double-check the linkage and also the float level. Hopefully the book procedure to check/set the float level is decent! I cleaned out that secondary diaphragm when I had it apart, and it seems to be moving nicely. By looking at it, I don't see exactly how & why that works. It looks like the secondary opens only by linkage, so that large aluminum poston seems to be only a damper or dashpot type thing (???) I didn't take the carbs ALL THE WAY apart, which I probably should have. I just cleaned the bowl, float needle, and both main jets & nozzles. I also appreciate the tip on the secondary opening earlier than I thought. I hate it when the factory manual doesn't give a theory of operation. I was guessing it opened at 3/4 or later. And yes; I agree that is a FUNKY carburetor setup. I guess it's one of those things that is great (when it works), kind of like the vacuum-nightmare A/C-Heat Climate Control in old Cadillacs. If I have too much headache with it, I might go aftermarket. Thanks, Charles

I'm a long-time visitor at this site, but newbie member... I am hoping to find some input on my '89 XT600 that I recently bought as-is. It was sitting for several years, and had the usual issues with non-use. I got it running with a new battery and tires, cleaned tank & carbs. 9K orig miles. The problem is that at about half throttle (being ridden; not in Neutral), it hesitates like it's starving for gas. Then if I crank it wide open, it has great power again and is smooth. Let off to half, misses again. Starts on first kick, and idles like a dream. Since hesitation and skipping is only at half throttle and only under load, I am guessing it is in the primary carb. If it were electrical, I would think it would still miss no matter how much throttle. If it were in the secondary carb, I would expect it to be bad only when the secondary is in use (3/4-FULL throttle). I re-cleaned the main jet and nozzle, but that didn't help. Plenty of gas flow into the bowl, and the spark plug looks good. Anybody seen this problem? I'm not a M/C mechanic, but I am trying to use common sense to troubleshoot this problem. On other threads in this forum, people pointed at the CDI box... I hesitate to blame that though, because again; it instantly goes back to smooth power if I open the throttle wide. The CDI box doesn't sense where the throttle is held, only the engine RPMs. Thanks for your help and suggestions, Charles Los Angeles area