First Impressions

[Ieat4strokes]

Ok, I had a 4mill full drag ported motor built by FAST a while back, weather hasnt really allowed me to REALLY ride it until today. Ive been running C12 in it tooling around yard breaking motor in and a couple high speed runs down the street n back. Going by plugs and plug chop jetting is on. Im running 162 mains and 55 pilots at 200ft absl. Got a smokin deal on some Sunoco 110 so switched to that. Had some great weather today and had about a gallon of c12 left in tank, topped it off with Sunoco 110 and made several 1-6th runs in a field near house, LEAVING in 2nd. Ran awesome for about 20 mins, then starting missing a little and falling on its face when I launch in 2nd . This is the first time ive ever ran Sunoco...QUESTION is do yall think it could be the Sunoco? How big of a difference in the c12 and Sunoco? Also what is this milky stuff in pic on my clutch window?

 

[bbcmudtruck]

Looks like you have a coolant leak. Its leaking into your cases, probably around the water pump.

 

 

[Ieat4strokes]

That's what I was thinking. Either that or clutches? Clutch dust? Also what about the missing and falling on it's face? It ran great for the first 20 mins I'm thinking because there was still c12 in tank. And when it ran out and was running pure sunoco it ran like ass. Trying to launch in 2nd it would just bog and act like it wasn't taking gas and when it would clear out it would spitt and sputter. Not bad, but enough to be noticed. Never done that before ever. Buy never ran sunoco either

[captainhowdie]

Sunoco is surposed to be some of the best gas out there. Its all i have ever used and never had a problem. Official fuel of nascar...so its gotta be decent

[broncbob]

The jetting may have changed on you. Different fuels have different amounts of oxygen int them? I'd do another plug chop with the new fuel only in it and see.

 

How long has the oil been in? It may have gathered some water out of the air?

[Ieat4strokes]

The jetting may have changed on you. Different fuels have different amounts of oxygen int them? I'd do another plug chop with the new fuel only in it and see.

 

How long has the oil been in? It may have gathered some water out of the air?

 

Didn't think about that. The c12 is oxygenated and the sunoco isn't. Maybe affect jetting. The gas was mixed minutes before riding and oil was new. Tranny oil has been in it over winter. I'll change it and see if the milk still exsists. Gaskets are new, motor was just completly rebuilt. Also I added CPI oof's, first time running them, had T5s on it, and last but not least timing? I'm at +7, and it was great while motor wasn't hot, seemed after about 20 mins and motor warmed up is when it spitted and sputtered and fell on it's face launching. High timing cause that?

[Ieat4strokes]

Cmon gurus. Suggestions?

[broncbob]

+7 on the timing is kinda a lot of timing on gas. I'd back it down to +4 and work up when you get the jetting spot on.

 

I trust that you did a plug chop with the new pipes on? The CPI's sould give you a great deal more over rev than the T-5's. It sounds like you just have a few tuning problems to get through. You may have to change gearing with the CPI's as well to pull the launch you want.

 

Putting together a new engine and dropping it in doesn't mean that you have reached the end of the work. You have to tune the gearing to the new engine, and now the pipes.

 

Through the winter on the oil huh? I be that it has some moisture in it, and when you got it good and warm it evap'ed out of the oil.

[cobrabc1993]

x2 .... Change the oil, and see if the milkyness goes away.... Its been a long winter, and depending on where your bike is stored, it could have took on condensation.... On the missing and crapping out,,,, you may want to recheck your jetting.... I had a banshee last summer that ran hard hard hard for about fifteen minutes.... Then, just like clock work, it take off alright, but spit and sputter on the big end everytime.... My needles were off a notch, and the mains were a step too big....

[Ieat4strokes]

Ok ill change tranny fluid today, mine runs fine on the big end, just bogged really bad at launch...But only after several passes.... first 5-6 or so passes pulled 2nd gear no prob at all. While warm, Even at idle, in neutral, if I smashed the throttle it would bog for a sec then pick up. To lean or fat? Have not done plug chop since I put cpi's on.

[tedd1]

...Have not done plug chop since I put cpi's on.

 

That's where I would start. Make sure jetting is good. Changing pipes and fuel will affect tuning.

I also agree that +7 may be a little much for gas. I would bump it back to +4 and start there.

 

Rick

[tundish2800]

What kind of carbs do you have? I have 34pj's on mine i thought i was rich but i was lean went up a jet size and it cleared it right up. thats when i was running110 sunoco mixed36:1 with super techniplate

[Ieat4strokes]

Thanks guys. I'll get a plug chop done and post some pics. Also I'm running 35 pwks. In sig! Jeff put it at +7 when he built motor. I haven't touched it. But I'll back it off a tad and see if that helps me. But first Ima get a plug chop done stay tuned for pics

[firebanshee]

Call up your motor builder and get his input.

[Ieat4strokes]

Have done so sir. Have sent him pms concerning this ordeal and he stated "looks like you got all the info, time to get to work" so I'm taking timing being too high and evrything mentioned is correct? Shrugs I sent him a link to this thread and had him read over it.