Recently Purchased A 2000 SRX 700

[lil3incher]

The chassis is in rough shape but the the engine and all parts are in very good condition, I performed a compression test on the engine, Left to Right the PSI was, 125, 130, 125, Is this a good number because I also have a 1998 VMax SX 700 and it has 147 PSI across all 3 cylinders, wondering what they shoulld have new and should I worry about engine trouble???

 

[Gregsyamaha]

As long as they're close to even and above 100 you're good. If one cylinder has a big difference, then your into trouble!

 

[roudyroy1]

that v max must have shaved heads or the gasket mod

 

[lil3incher]

Yeah roudyroy1 you may be right, She do fell more powerful then she should, and also I shouldn't worry about 5 PSI difference?

 

[justin1620]

Your compression is good on all 3. Nothing to worry about.

 

[Devilin AblueDress!]

Yeah roudyroy1 you may be right, She do fell more powerful then she should, and also I shouldn't worry about 5 PSI difference?

Most say within 10% of each other.

 

[lil3incher]

Thanks alot guys, This is my first power valved triple, Very excited about it

 

[roudyroy1]

that 5 psi difference is on the pto side, thats because it has a different size head. its supposed to be like that idk why the other one is but its not a big deal

 

[Devilin AblueDress!]

that 5 psi difference is on the pto side, thats because it has a different size head. its supposed to be like that idk why the other one is but its not a big deal

Never heard of this on a SRX........Enlighten us? Maybe you were thinking of the Viper?

 

[roudyroy1]

on an srx and viper, the pto cylinder head has a larger volume to reduce compression in that cylinder. the idea is that since that cylinder has to deal with heat from the clutch and all the stress from the other 2 cylinders putting energy through the crank it gets hotter. the reduced compression causes that cylinder to not make as much power thus producing less heat. on red head engine all head volumes are the same, so instead they run staggered jetting, the pto cylinder is richer than the other 2.

 

[Devilin AblueDress!]

on an srx and viper, the pto cylinder head has a larger volume to reduce compression in that cylinder. the idea is that since that cylinder has to deal with heat from the clutch and all the stress from the other 2 cylinders putting energy through the crank it gets hotter. the reduced compression causes that cylinder to not make as much power thus producing less heat. on red head engine all head volumes are the same, so instead they run staggered jetting, the pto cylinder is richer than the other 2.

Sorry but NOT SRX, SRX heads (all 3) are the EXACT SAME AS THE OTHER 2. Pretty sure all Yamaha come from the factory with staggered jetting.

 

[roudyroy1]

i stand corrected then.

 

[Devilin AblueDress!]

As far as SRX goes the 98-99 (8DN00) are the same and 00-02 (8DN10) are the same. Should not mix the two different heads on same motor.

 

[roudyroy1]

That's what I must of been thinking of for the srx engine

 

[munisean]

The viper engine (mine =2003) has the diff compress on the pto. Learned this the hard way after removing heads to investigate.
I had a broken reed. Nothing like learning the hard way.