97 xp 787 won't start when warm

[bbanich]

Starts ok cold, revs and idles great on trailer hooked up to garden hose. Runs good at WOT on the water. Sometimes boggy when accelerating from idle on the lake, especially when not going to WOT. Will idle for about 5-10 seconds while on the lake, but then has to be given a little throttle to keep from dying. Runs good with throttle just slightly applied, but a little more than that and it's boggy. The big problem is that once you shut it off after riding, it won't start back up with the engine warm. Sometimes if you crank the engine for a really long time while giving it some gas it will gradually sputter and eventually get going, but usually I can't get it started. When it was doing this once I put it on the trailer, changed the plugs, and it started immediately with no throttle. That leads me to believe that it is overfueling and that's why I can't get it started warm. Have taken the carbs apart and cleaned and replaced the internal filters as well as replaced all the remaining grey fuel lines. However, I couldn't get the check valve cover off of the jets due to stripped screw heads so I just sprayed carb cleaner and blew it out the best I could. Thoughts?

 

[Dr Honda]

Please dont take this the wrong way... but you can't do a carb rebuild half a$$'ed. First of all... you can't get a good spray into the main jet with the block in the way... and... the carb clean may destroy the Mylar check valve behind the block.

All you can do is drill the heads off the screws, and hope the aren't seized into the carb body. But, normally... once the head is off, and the block is out of the way... the screw sticking out will just unthread.

 

[bbanich]

Thanks - no offense taken. I'm a newbie and appreciate all of the new learning. I have a question about setting the low speed adjustment screw while we're at it - it says the setting is one turn out. Is that one turn out from it being turned completely in until it stops?

 

[Dr Honda]

Yep. Turn it in till it stops, and open it one full turn open.

 

[JJinSC]

The service manual states to turn it in until you feel a slight resistance then turn it out 1 turn.

 

[6KJR]

So Im thinking you need to pull the carbs off. Clean them at least. Grey fuel lines still?

Check your fuel tank VENT line. If its plugged and the tank gets pressure itll pump the fuel through the carbs.

Rotary valve clearance is usually a sign of poor starting when hot.

 

[bbanich]

Thanks...another question in regards to the carbs. The manual says to check the needle valve for a grooved condition and replace if necessary. Does that mean it should have a groove, and if it does it is ok, or if it has a groove it should be replaced?

 

[jerrygena]

if grooved, replace