OK, seeing as its quiet, heres one for you. I've got an 83 XT600 - the one before the one with the electrc boot, with those stupid red radiator cowls on the side of the tank, presumably there to cool the horn as its air cooled. Its been lurking at the back of my shed for some time now, but whenever it comes out it has the same problem, namely it wont start from hot. From cold its fine, 2 or 3 kicks at the most, but ride it for 20 minutes, stop it for a moment and the bast**d thing wont start again for 20 minutes. Makes stopping for petrol a very lengthy process, usaully involving lots of sweating and swearing. I've checked valve clearances, twice now, in case I ****ed it up the first time, and fiddled with the pilot air screw in both directions, and its still the same. What should I look at next?
I had a similar problem with one of my bikes, it would start from cold and run fine, but when it got hot it was a right bug*** to start again, it turned out to be the spark plug which i suppose must of been breaking down when hot?
Try this:- Plug good idea anyway. Get the engine up to temperature (a ride around the block is better than idling), Slow the idle speed to less than normal (say 1000 rpm), then adjust the idle mixture to highest rpm, if it gets above normal slow it down again and readjust. Be careful not to get the engine too hot, take it round the block to stabilize. When you get the highest rpm readjust the idle speed to spec. Then weaken the idle mixture a fraction 1/4 turn max so the idle speed just slows a little. Try starting with little or no throttle but above all keep it STILL. If this doesn't fix it it could be the float level is too high probably due to worn float needle valve in which case the Carb needs to stripped and checked for wear and rebuilt with new parts as required then reset as above having reset the float level. Hope this helps. Cheers, Neil.
I Had an XTZ 750 for a few years. The main problem was plastic choke needles. Does yours have plastic choke needles? If so, check them for wear. They usually get worn out by vibration in the brass housing and lead to the bike being choked all the time. Backfires will be fairly common as will a lack of throttle response if they are too far worn. This might be why it's not starting when hot. Just thought i'd throw another idea into the mix!
Kindest regards
Nevil
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Good stuff. I'll start with the spark plug and work my way up. Might be a while cos its burried under a pile of stuff and currently has no MOT, but I will get round to it sooner or later.
