I have a Mojave. Seems it needs to warm up for about 10 min with full choke. If I try and turn choke down/off before then it stalls. But once it's warmed up I can take choke off and she purrs like a kitten. I can shut bike down and fire it right back up. So once warm there's no issue at all.

What could be the problem here? Surely it shouldn't take this long to warm up.

Carb has recently been ultra sonic cleaned.

Only mod is removal or the snorkel and a few holes in air box cover with some Uni foam plugs.

 

Did it do this before the carb cleaning?
Is it better or worse since cleaning?

 

Carbs are jetted from the factory based on air flow from factory airbox. Now you have drilled holes in the airbox and increased the airflow so it is probably running a little leaner than original airbox would allow. I would want to take a good spark reading after a hard run, if to lean it will burn a piston. Possible carb rejetting might be needed depending on plug reading.

 

I recently bought it used. But I'm going to say it needed a long warn up before the carb cleaning. I only had a chance to get it out once after I bought it. I hit a jump which dislodged some gunk and jammed up the jet. But I do remember it kept stalling the 1st time I fired it up and tried to drive it too soon (pre-carb cleaning).

To the other persons point, I do understand. Just not sure being lean would cause such a long warm up? But I don't know. Thanks for all your input.

Does running lean make you slower? I had the carb cleaned and modded the air box simultaneous and feel like I've lost a step. But this could also be because I'm now used to the quad now. Things always seem faster when you first get them...

 

Yes, lean can make you slower, also makes engine run hotter and this is where the piston or valve can burn. If the engine runs rich it just fouls plugs but doesn't really hurt or damage anything, however lean is another story. Don't know if this is your problem or not, just making suggestions for things to look at. I would check it out though just in case there is a problem so you don't mess up the engine.

 

I've always understood running lean will generally increase power, but I'm not an engine expert and increase in power is based upon a baseline of not running lean. Running lean will also make the engine run hotter but that may not be something you really notice.

For longevity of your engine, running lean is your enemy.

 

Running lean on a two stroke engine will make more power and rpm but not on a four stroke engine...well mabey for a few seconds but that is all, in general a lean condition will lose power on a four stroke and increase internal temps to an unsafe level that can cause metal to start melting.

 

Thanks all. I just talked to a local atv repair guy and he said the reason my warm up taking so long is the lean condition. So looks like I can kill 2 birds with one stone by jetting.

Can the jet be changed without removing the carb? It's a real PIA to get this carb off with the way it's connected to the air box.

Also,..any advice on which jet to start with would be a huge help (# and brand). I'll be Googling for this info in the meantime.

I have a Dynojet jet kit (comes with adjustable needle) but was told by a guy who specializes in carbs that these kits are far from optimal. But this is one mans words.

Thanks again!

 

Years back I played with carbed atv's and did some rebuilding but nowadays with EFI it just isn't needed and is so easy. Getting back to the old days...I used the "UNI" company for my carb needs and they were always quite good and their kits always showed noticeable performance improvement. I just called there service tech and told them what machine, engine and any mods that were done to it. They would send me a complete carb rebuild kit with instructions for making the various settings and the necessary jets. Easy and they worked very well, plug readings after installation were always right where they needed to be. Never an issue....I believe they are still in business. Whomever you choose for the kit, do a complete clean and rebuild with all new gaskets. A quick clean and reassemble will generally cause more problems in the long run. Be thorough and do it right for best results!!