416 runs lean... Why?

[DantheEXman]

I just got my 416 built. Its 11:1 compression, hotcams stage 1, Sparks advance timing key, holes in airbox, K and N filter, Sparks X-6 exaust. It runs waaay to lean. The ceramic sleve on the plug is turning a little white at the very top. So I know its lean... But it has a 170 main jet in it. Whats the deal?

Shouldent this be rich? 42 pilot and 170 main. Its overheating bad. Where should my needle jet be? I moved it from the stock position up (clip down) one notch from the bottom to richen it up, it helped a little, but before this the plug was totalle white. Now its like I described above.

I hear that timing keys should not be used on heavily modded motors, could this be the cause of it running way to lean? Should I move the needle up again to put the clip in the lowest position? I dont have any air leaks. I cant figure it out. I shouldent have to go higher than a 165 main. Whats the deal?

Someone help me please.

What octane gas are you running???

[DantheEXman]

89 I know its bad. I have to get 93. Is that why? I feel stupid.

Originally posted by DantheEXman
89 I know its bad. I have to get 93. Is that why? I feel stupid.



:eek: :eek: :eek:

IT's probably gonna run bad with 93 too..:(

[user101]

yup..sounds like the fuel is ur problem. with a 11:1 piston you need atleast 50/50 mix of race gas and 93.

[DantheEXman]

I just got some 93. From what I hear it should be fine with 93.

[hondarider2006]

It will be better if you run 50/50 though

[DantheEXman]

no race gas in my area, any substitutes? Octane booster?

I'm surprised you haven't read all the post on here reguarding 11:1 and pump gas. 93 is a definite from this point on but it's probably starving for something higher..:(

Some will say it's fine with 93 but 8 out of 10 people that have 11:1 say 93 just doesn't cut it for their motor. I'd have to believe the majority over the minority on this one.

I have race gas right down the street from me but knowing my 10.8:1 will run on 93 and run even stronger on a 50/50 mix is what sold me on my compression. I didn't want to rely on race gas all the time, not even part of the time. When my racing days are over it's a good piece of mind knowing I don't have to spend $4.25 for a gallon of gas..

[DantheEXman]

I dont race so I dont need a high performance gas. Would 4 octane points really make it run that much hotter? (93-89) Or is it the degree key. Thanks rico, and others that helped me out.

[honda_74]

I just sold my 440ex. It had a 175 main and a 148 pilot i think..port, polish, cam, all that great stuff. People told me that i would have to run race gas but i ran 93 quite a bit and it didnt make it run bad, just didnt come alive as much as it did when i ran the 110 octane.

[xc400ex]

Take the timing advance key off. That will cool it down alot. My 11:1 426 runs on straight 110 with stock jetting and its a cool running motor.

[DantheEXman]

Is it really worth it to use race gas for trails?

dude race gas isnt just for racing its for anything. If your engine is running hot you will need to get at least 50/50 mix if u didnt know that before ur rebuild well now u do.

[Aceman]

Get rid of the timing key, put the needle clip back to the middle position and start running at least 93 octane. I bet your problems will be solved.

[UglyMotha™]

i've got a pretty well modded 416 11:1 and the advance key and i have to run a mix of race fuel, and no, octane booster is not a subsitute, it will actually make your motor run hotter

[cals400ex]

Originally posted by xc400ex
Take the timing advance key off. That will cool it down alot. My 11:1 426 runs on straight 110 with stock jetting and its a cool running motor.


i would be careful with the stock jetting.

Originally posted by DantheEXman
Is it really worth it to use race gas for trails?

The reason for the race gas is not because we think you race but the pistons compression that you chose. I'd take the key out like recommended and only run 93. It might solve the problem but not a definite..

and yes there is a big enough difference between 89 and 93.

[KASCHAK]

perhaps you should've read before you went out and started buying parts. anything above 10.8:1 should run 50/50 or straight race. 10.8:1 you can get away with 93 pump gas.. luckly i have 98 were i live its only 8 cents more then 93. i might be able to get away with a 11:1 with the 98 but not all gas stations have 98

[DantheEXman]

Originally posted by KASCHAK
perhaps you should've read before you went out and started buying parts. anything above 10.8:1 should run 50/50 or straight race. 10.8:1 you can get away with 93 pump gas.. luckly i have 98 were i live its only 8 cents more then 93. i might be able to get away with a 11:1 with the 98 but not all gas stations have 98

Alright, I dont know why you guys take me for a dumbass that just bought a bunch of parts and doesent know ****. I know race gas is not just for racing. I didnt mean it like that. But I did read all about every part I put in my bike. Except the Clutch kit because I thought It wouldent matter what brand. DONT get a Barnett. I know the timing advance makes it run hotter, and I know I have to take that off If I want to run 93. And 11:1 WILL run fine on 93. Just not peak performance.

I just wanted to know why it was running hot. Thank you guys for helping me out. So, Im going to take the timing key off, and run 93 octane untill I can order some race gas. Anyone have a good place to order race gas from? I was just confused why I put in a 170 main and It was still lean. I guess its the timing key and the gas. Thanks guys.

[F-16Guy]

Does it knock/ping when you're riding it? When I broke my bike in it needed a little more octane than super had, no doubt because of the tight tolerances and the extra heat that goes along with them. I can get away with super now as long as I don't work my bike too hard. I run at least 50/50 avgas (usually straight) in the dunes and there is no pinging at all, even when I race people up the dunes. I broke my bike in with a 170 DynoJet main and a 42 pilot and it ran a little rich. I now run a 160 DynoJet main and it's about perfect. DynoJets are a little different than stock, but I don't think you should be running lean with a 170. Take out the advanced timing key and check your engine for any possible air leaks. You can substitute avgas for race gas if you want to see if the added octane helps. You can pick up some 100LL at your local municipal airport for about $2.30/gallon.