new cdi for v-force scary thought
#21
Originally posted by: Crankdog
Since someone is talking about pistons, does anybody know if a 11:1 compression is available for the 650 in a standard bore. Thanks,
Crankdog
Since someone is talking about pistons, does anybody know if a 11:1 compression is available for the 650 in a standard bore. Thanks,
Crankdog
#22
Sometimes longer duration cams can lose a bit of bottom end.Quite often a bit more compression makes up for that and more.
Often what are called 11:1 pistons only cc to be about 10.5:1 . these are no exception. It will be even a little lower with porting.
Even with additional timing it still runs fine on pump gas(premium).
As far as warranty,My opinion on that has always been that it mostly depends on the dealer,but I would never expect a dealer to cover my own self inflicted problems if they arose anyway.
Often what are called 11:1 pistons only cc to be about 10.5:1 . these are no exception. It will be even a little lower with porting.
Even with additional timing it still runs fine on pump gas(premium).
As far as warranty,My opinion on that has always been that it mostly depends on the dealer,but I would never expect a dealer to cover my own self inflicted problems if they arose anyway.
#23
helix and shotgun think u got the cdi thing wrong yes it is 28 degrees btdc at 5000 rpm and up it fires but it dont need to retard it more to 32 we need to advance it closer to tdc before it fires like it fires at low rpm which is 5 degrees btdc why it got so much low end thats what we need at mid and top end to fire close to tdc as u can get
#24
I think you've got it backward. Advancing time is when you are making a spark earlier in the compression cycle. It fires on the way up to compression, detonation is when you get the spark to early in that cycle.
The advanced timing fires before it reaches top dead center, because the flame front takes time to fully combust and push the piston downward.
The advanced timing fires before it reaches top dead center, because the flame front takes time to fully combust and push the piston downward.
#27
Shotgun is correct. Just think about it. The combustion process takes time. If you time it just right, before top dead center, then you take advantage of the full flame front once the piston moves past TDC. Too early or too late and you lose the combustion power on the power stroke. Preigntion (too much advance) causes the flame front to push against the up-moving pistion.
The faster the rpm's, the more advance needed to keep the process optimal.
Here is an explanation if you don't believe it.
Here is another.
Do a web search for more proof if that isn't enough.
The faster the rpm's, the more advance needed to keep the process optimal.
Here is an explanation if you don't believe it.
Here is another.
Do a web search for more proof if that isn't enough.
#30
fullthrottle;
That's my point. I haven't figure it out. I own a 650 and we need one, I not sure a V does.
Maybe 32 degrees all the way isn't the best timing, I don't know. If I had one I'd be finding out.
That's my point. I haven't figure it out. I own a 650 and we need one, I not sure a V does.
Maybe 32 degrees all the way isn't the best timing, I don't know. If I had one I'd be finding out.


