650/X-2 winter x2 build

[TheCoz43]

It is well over 300! no typo, it is only a bench test, what do I do put my other domes back in or run it?

 

[Snivilous]

What size domes are they?

Assuming your compression test is accurate, I would lower to ~220 psi, run race gas, see how you like $10/gallon or what ever it is, and then move from there. What engine are you running? I would be afraid you'd blow your head off at 220 psi with a 650 or 750 engine even. Unless you've done a lot of research and know that people have run that high of compression before and safely, though like I said, in that case it will boil down to if you want to spend $50 on gas per ride by running race gas and then boosting the octane even then (forgive my ignorance if there are different race gas octane levels, never used race gas before).

 

[TheCoz43]

21cc domes, test is for sure accurate, like you say it would prob blow head off or destroy bottom end, I think I will put the damaged domes back in see what the psi is, any way how bad ass is Austin's ski?

 

[Austin]

Thanks coz! Yeah I am running 28cc domes and I should be around 175psi but I have 22cc domes to run 215psi when racing. I am going to test my compression here once I find my gauge

 

[Snivilous]

I was gonna say, most people seem to run 33-35cc domes at sea level.

His X2s pretty bad ass! Love the nose and hood, came out really nice I thought. I didn't ride it, but it sounded mean. I especially like how he had to zip-tie his handlebars on lol

 

[Vumad]

I think the color choices came out very nice.

 

[Austin]

Thank you! I am very excited with how it came out!

 

[TheCoz43]

what was causing it to backfire?

 

[Austin]

The little key/shim that goes between the crank and fly wheel was shattered! so the fly wheels was kind of turning on its own, so it was sparking when ever it wanted too.

 

[dbattersby20]

woodruff key

 

[Edwardsjr1]

Gnar

 

[Austin]

So ran a compression test last night and my ski is at 195psi in both cylinders, So I need to find some 30cc domes I think! I am running o-rings only so I was thinking about throwing a gasket in there to see if it helps... Any thoughts?

 

[Snivilous]

What domes you running now?

 

[icecoled007]

What domes you running now?

28cc

 

[TheCoz43]

Comp Test

My comp test was inaccurate due to no carb and pipe being installed plus, cylinders had fresh oil. Is it ok to run gaskets with domes intended for o rings. Why do you want 30 cc domes? What are pros and cons? I have also broken a few of those woodruff keys, can you get a higher strength steel?

 

[Austin]

I ran my westcoast head in the past with gaskets and orings, so I assume it was fine. I want to run 30cc domes to try and get the compression down in the 170 to 180 range. Anything over about 180psi you should be running race fuel, and I really dont want to run race fuel beacuse its so expencive.

 

[Snivilous]

Unless you are hearing predetonation, I wouldn't worry. I would run race fuel if you are over 200psi, but I would think 93 would be fine at 190 +/- 5, though that's just me lol

 

[Austin]

Once go over about 170 to 175 you take away reliability.

 

[dbattersby20]

you'd probably be fine as long as you don't have a timing advance and you doing hold it WOT. but you're planning on running buoys correct? so i would say you are right to try to lower it.

 

[Snivilous]

Once go over about 170 to 175 you take away reliability.

Reliability with what? That it won't predetonate?

Though yea, I agree that with advanced timing and 195psi, 93 octane is probably too low.