CRF Won't start Cold

[mooseracerX]

Hello.
I recently rebuilt the entire motor. Crank, Piston, cylinder, seals, different clutch. It is a big bore piston and cylinder and a stroker crank. Has a hot cam stage two, ported. The problem is the quad won't start when its cold unless you pull start it with another atv, etc. The valves clearance is right on, the timing is on. We've triple checked these things. We've changed the jetting and that seemed to help some but maybe we still need to go bigger? We've tried different fuels also. Weird thing is it will start the 1st kick with the hot start when it is warmed up. This is baffling us. If you have any idea's please let me know. Thanks in advance.

[Lasher]

Just getting into the CRF motor this year, but I wonder if it is something in the carb? At first I would have said valves (by what I have read) but that carb has some funny stuff. I am using the stock CRF carb.

I also know the starting procedure is something to be followed. A couple pumps of the throttle, choke all the way out, neutral, slowly kick over until compression stroke, then give a good solid kick.

[lsr_quads]

I know with my crf hybrid, I have to;
1) five easy kicks (to prime it)
2) full choke
3) full hard kick (no throttle)

**has to be in neutral or it will not start** (no idea why though)

maybe this might help, just the series i have to do

[mx Eli]

seems like its the carb if valves and timing are spot on. take it and get dyno tuned it should clear that up

[mx Eli]

Also have you checked compression with leak down?

[mooseracerX]

Alright thanks guys. No we haven't but I'll check into it.

[josborn]

I have to choke mine onthe first start of the day, after that 1-3 kicks, unless its late in the day and the filter is getting close to needing changed.

I would say carb. Needs either more air, or more fuel.

[mx Eli]

I would say mess with up and down pilot jet sizes. migth have to adjust needle alittle then

[number52]

sounds like your intake valves are worn out. Even if your valve lash is correct they will still leak enough air past to make it hard to start. Once warm, you need more air anyways and that's why it's easier to start then. Let us know

[audioworks04]

Have you checked any of your electronics? I had this exact same problem and it ended up being a bad coil. Just remember to check the cheap simple things before you go crazy sending in your head to get redone.