Hard start after rebuild

[williat]

Just did 416 build (JE 10.8:1; Hotcam Stage II) and it runs well. But after the quad gets warm, it becomes extremely difficult to start. Battery's in good shape and sounds like its trying to start, just doesn't quite get it going. I wondered if the hotcam was the problem since I took out the decompressor mechanism, but after reading a fair amount on here, it looks like that shouldn't be an issue. Any suggestions?

[zrpilot]

There are too many possibilities, but I would think plug or carb.

[williat]

I'm certainly no expert, but I guess I don't see why it would start normally on initial startup, but have trouble with hot starts, if it were just the plug or carb. I'll try the plug, but don't think its the carb because I had it off the bike and cleaned it top to bottom before I took it out. Any other thoughts on this?

[zrpilot]

What has changes as the engine runs, temperature is one. If the carb were grossly rich (not saying it is) then it might start when cold and create a hard start when warm.
What if the choke were partially shut? What if the plug changed resistance once it warmed?

I dunno???

[drew416ex]

what size pilot jet do you have?

[williat]

My plug looks pretty good, so I think my jetting is reasonably close. Pilot is 42. Thanks for trying.

[zrpilot]

If I were you, I'd start with a new plug.

Are there any air leaks?
Did you check to see if the choke is fully off?
Did you check the float height?

[williat]

Choke is fully off. Will replace plug and check air leaks and float height. Thanks for the tips.

[GOTFEAR]

well you got more compression you should get a better battery like a gsxr1300 battery

[86 Quad R]

alot of times a hot start issue can be contributed to a seaping float needle seat or a little large on the pilot jet or another possibility is the valves being adjusted a lil tight.

[zrpilot]

Originally posted by 86 Quad R
seaping float needle seat
valves being adjusted a lil tight.

Good comments, had not thought of those!!!

[williat]

Thanks for all of the suggestions guys. I'll keep trying these and hopefully find the solution.