northernSRX
New member
there's a guy selling a set of Mr Viper ported cylinders for an 01 srx n kijiji for $500. He tells me 2 of them have a couple scratches barely noticeable with a finger nail one looks like needs a re-nik. Are they worth it? and would the power valves need to be included from the ported cylinders?
Thanx
Thanx
should ask him what year they were ported. To my knowledge mrviper has a new porting kit or something in that nature that allowed for a more thorough job
If any work is need on a cylinder, it only can be used as a core value. Power valve dimensions would not need to be modified for port work, only a Big Bore so you could use the ones in your sled as is.
IMOP, If 2 cylinders need work to put back into Yamaha Specs, I think he is looking at $300 best.
Keep in mind you will also need to pay the extra expense to have your heads machined to make up compression for the port job, (raising the ports)
If any work is need on a cylinder, it only can be used as a core value. Power valve dimensions would not need to be modified for port work, only a Big Bore so you could use the ones in your sled as is.
IMOP, If 2 cylinders need work to put back into Yamaha Specs, I think he is looking at $300 best.
Keep in mind you will also need to pay the extra expense to have your heads machined to make up compression for the port job, (raising the ports)
northernSRX
New member
what do you mean by machining the heads? geting them shaved or re-working the dome
heads are cut depending upon the gas used by the customer, some are flat cut, while others are cut and then remachined squish angle and clearance. It just comes down to what your doing with the sled, and most importantly, what fuel/gas your running in it. 
I sent you a pm.
I sent you a pm.
on the gas thing, if a head we're to be set up for the worst fuel possibly. Would it work better with good quality gas? or any type of gas if already setup for poor gas. I dont know what kind of gas we get and wanting to get some porting done.
SRX-SKI said:
if you have a viper you dont need any headwork done as the compression is already high.
Mac
Member
SRX-Ski,
If I understand your question correctly. The question is - if an engine heads are set up for low octane fuel will there be an advantage to running premium fuel or race gas in the future? The answer is no.
I notice you are from northern Quebec. Nunavut is very far from lower Canada where I ride in Lake St. Jean. You should find out what octane is available because this will determine how to set up your engine. Who knows fuel might not be any different in northern Quebec. As Mr Viper points out Vipers are set up with high compression from the factory. Many riders reduce compression when installing pipes to prevent burndown but if your fuel octane were real low you might benefit from a low compression head too.
Keep in mind that if you were to find higher octane fuel after this modification your engine would produce less power. Running premium or race gas will provide extra protection from burn down but will not increase HP.
If I understand your question correctly. The question is - if an engine heads are set up for low octane fuel will there be an advantage to running premium fuel or race gas in the future? The answer is no.
I notice you are from northern Quebec. Nunavut is very far from lower Canada where I ride in Lake St. Jean. You should find out what octane is available because this will determine how to set up your engine. Who knows fuel might not be any different in northern Quebec. As Mr Viper points out Vipers are set up with high compression from the factory. Many riders reduce compression when installing pipes to prevent burndown but if your fuel octane were real low you might benefit from a low compression head too.
Keep in mind that if you were to find higher octane fuel after this modification your engine would produce less power. Running premium or race gas will provide extra protection from burn down but will not increase HP.
ok, thanks mrviper and mac for helping.