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booneTRX
10-17-2001, 11:59 AM
For those who have a 440 big bore: What jetting are you running? Mine will only idle with choke full on with a 155 and a 160 main. Any changes to pilot jet? Other mods are below.

Thanks guys.:D
10-17-2001, 01:21 PM
if choke has to be on to run right then you are lean, you need to richen it up, fellow ex'rs please correct if I am wrong
10-17-2001, 01:38 PM
I think you're right.

I had MAJOR probs getting my bike to idle/warm up after having the engine mods below done. Finally, a 170Main / 40Pilot fixed my probs.

BTW, my airbox has a 6-inch hole cut in the lid, with a directional vent/screen covering it. I should be running without a lid, but I like this setup better--keeps more water out.
FatBoy Redrider
10-17-2001, 03:40 PM
170 will fix it up. I also added one of those carb vent kits. That seemed to stop the bogging.
nakomis0
10-17-2001, 03:51 PM
my 440 runs a 168main
booneTRX
10-17-2001, 04:22 PM
Thanks guys!!! Like I say before:"EXRIDERS RULE!!!!"

I will pick up a 168 and 170 main and try a little beefier pilot also. I will let everyone know tomorrow how it works.:macho
booneTRX
10-18-2001, 11:58 AM
You guys helped ALOT!!!!!!!!!!!!

Today I popped in a 170 main and a 40 pilot. Fired right up, idles nice, and my god the torque difference from the stock motor.

Its nice having knowledgeable people to refer to when the going gets tricky.:D
10-18-2001, 01:31 PM
Word!

Not all the posts on here are flames and "my quad is faster than your F15". Most of em are, but every now and then, someone has something useful to contribute.

Even though mine is a 416 bore, I had similar symptoms as you...I received advice from my atv shop to go with a 170/40....glad it worked for you too.

Now throw a 16T on the front of that torque monster to really make use of the added pull...
booneTRX
10-19-2001, 04:57 PM
MIA......... try a Sparks flywheel key. I have all the torque I need to handle. It gets the revs up much faster. I can dog it in second gear where it barely is running, blip the throttle to 1/2, and the front end is dancing nicely.:macho
FatBoy Redrider
10-19-2001, 07:16 PM
I recently ordered the sparks key. My front sprocket is shot so I bought a 14 tooth. Do you think my 440, cam, fly key, and a 14 tooth will be a bad combo. I'm think the little bit of low end i would lose from a 16 tooth will be gained back with the sparks key. this will give me the same low end but more top end with faster acceleration. any thoughts?