ok, i cannot jet it correctly because i keep getting this dry black plug reading!! Could this mean i am burning oil? or running rich? i took it as both. It is not wet at all, a black coat of crap on the plug, not thick, just... there.

i am burning a little bit of oil, but i just got everything back together, so i figured this was normal. i am not running it hard, and during the first few hours i barely hit the throttle! (not consecutively, every other 10 min i'd ride, then it set overnight.

how long should it smoke after the rebuild? it is not constantly smoking, but at a blurp of the throttle around 1/2 throttle i get a small puff of white smoke. then when i rev past that i get a puff of purple smoke. This is not a constant smoke, just when i hit the trottle. I looked under troubleshooting and it says stuff avout worn rings and crank case pressure. I cleared out my crank case breather hose (nothing was in it to begin with) and i still have the same setup. Dry black plug all the time, with some smoke. It also BOGGS ON THE MID-TOP END!!!!!! it is about 45=50 degrees with wet rainy, muddy conditions. someone tell me what's going on here?

later

 

Sounds rich, what is your jetting and altitude?

 

As others say, black plug, read immediately after wide-open throttle run, means too fuel-rich combustion mixture; usual remedy, smaller main jet and/or lower needle position.

I'm unclear on the number and sequence of your modifications; if your 400 ran o.k. and you ONLY installed he 416 kit, it should run o.k. AFTER the slight change in displacement and compression ratio with no changes in carburetor adjustment.

If you've changed the air intake, exhaust, and carburetor settings (are you running stock or oversize main jet?) at the same time, too many variables exist to pinpoint your problem by remote control.

If you still have the old parts, you might set it up as near as it was to the "before" condition (before you bored and re-pistoned it); if performance improves, then change one component at a time and note the effect. If performance DOESN'T improve when reverting to the near-stock setup, something went wrong in modification/reassembly.

Given the many possibilities, you might need to evacuate your quad to a hands-on experienced tuner with adequate tools and test equipment to make it right. Good luck.

Diogenes

 

Just got my 440 out of the shop and sounds like we may have the same problem. I have black smoke puffing when I blurp the throttle. Mine is set up with a 162 main and a 45 pilot. Don't know where the air mixture is set at. So I thinking about cutting the main to a 152 set the air mixture to factory setting (2 turns CCW) and start from there. I don't know if the pilot has anything to do with running rich so I will leave the 45 in until someone tells me different.

I run Klotz 113 and I was told that a accurate plug reading with oxygenated fuel is near impossible.

 

altitude is below 3000 feet.

i haev a dynojet kit, and i WAS running a 170, but then dropped it to a 165 and i am still getting the same plug reading.

I was in the process of jetting it correctly when my spark plug stripped and i ripped it apart.

the only modification i have done is remove the welds on the inside of the headers.

Maybe i'll try a 160, but i have to get a couple new plugs. i keep cleaning the plugs, and the electrode is going to wear away. Right now i have a splitfire in, with the same plug reading as the NGK's.

 

arg, darn Dynojet kits..I still fail to see their reason...anyways, I would say try and go buy a NORMAL jet from the honda dealer..try a 155, 158, 160, and a 162. One of those should do the trick for you.

 

I agree, Dill; a return to stock carb, stock adjustments, stock jets, etc., should result in an improvement--otherwise, something's haywire with the hopup rebuild/reassembly.

Sometimes I think people expect too much from jet kits; you can't improve on an optimum fuel-air mixture. Since stock jets conservatively approach optimum mixture with a stock machine, there's little room for improvement in the slightly-modified 416.

Diogenes

 

ijust talked to a pro himself....its deff your jet....you didnt mod too much... my kit included port and polishing race cam piston, etc etc, where as this needs jetting with the porting and cam, but not with compression with just a piston... so i would also suggest going back to around stock jetting with a 150 or 152 no higher than a 155 and i bet it will solve your problem...if you had gotten just a lil head work and/or cam, your 416 would be screaming even wiht the jetting screwed up,hehe good luck!

 

ijust talked to a pro himself....its deff your jet....you didnt mod too much... my kit included port and polishing race cam piston, etc etc, where as this needs jetting with the porting and cam, but not with compression with just a piston... so i would also suggest going back to around stock jetting with a 150 or 152 no higher than a 155 and i bet it will solve your problem...if you had gotten just a lil head work and/or cam, your 416 would be screaming even wiht the jetting screwed up,hehe good luck!