performance head

[spence]

i was wondering if a aftermarket head will bring down reliablility alot or make it louder? Please post need to know before auction ends!!!

 

[SXIPro]

No and No.

 

[FL-cracker]

A Girdled Head will add reliabilty, as you no longer will have to worry about cracking a cylinder.

ADA Is the head of choice around here, for most people.... I run a Greater Yamaha, with no problems.

180-190psi is what you want for pump gas.

 

[spence]

this one is a westcoast head. Shoeld i have a mechanic install it so it is done right?

 

[Matt_E]

180-190psi is what you want for pump gas.

Whoa whoa....slow down. That depends on many factors. 180-190 is fine on a stock or ported 701 Superjet without additional timing advance, reasonable squish, and good gas quality, all on an 81mm bore.

Change any of those, and you'll be in deto territory.

 

[Mouthfulloflake]

You can install a head your self.

remove old one, clean gasket surface, use new gasket, torqe to proper torque ( usually 22 ft lbs) in the proper sequence, refernce stock head for bolt tightening order.

torque them all to 12, then 16, then 20, then 22 or whatever, sneak up on it.

then you are done.

should take like 10 minutes, ad 20 minutes if you have an exhuast ( like stock) mounted to the head.

 

[spence]

i dont have a tourque wrench. is westcoast a good head? How much is the other stuff you were talking about like gasket

 

[Mouthfulloflake]

gasket is probably $25 or so.

you have to have a torque wrench goto autozone and buy one for $10, you will use it often if you wrench on your own ski.

 

[spence]

would any shop have a gasket? anything else i need how much will a westcoast head help?

 

[Mouthfulloflake]

check ebay, check local shops.

ronayers.com will have them as cheaply as anyone probably.
ive got some copper head gaskets for kaw 750, but not sure how well they work, ive never used one.

more compression will make the engine a bit snappier, or peppier.

You will likely need to start running 91 or 93 octane fuel.

 

[Mouthfulloflake]

stock part number is 11004-3708

at ronayers.com its $26.xx

 

[spence]

for both or one? how do you know what comp it wil go up to?

 

[Mouthfulloflake]

both what?

there is only one head gasket.

you dont know, until you figure the volume of the head and alot of other factors.

they are generally sold / advertised, as rec or race heads.

rec means pump gas, race head generally means you need race octane fuel.

 

[spence]

quote from seller: This Westcoast high compression head fits Kawasaki 750 Jet Ski engines. It has some oxidation/chipping paint, but is in good shape and will work great. Sold as-is.

asked what comp he said 170 psi on pump gas. What is stock?

 

[spence]

quote sxipro: A Girdled Head will add reliabilty will this add or deacrease reliability?

 

[Mouthfulloflake]

I would ask for better pic of the inside of that head, those domes look to have some pitting or oxidation.

I wouldnt run it unless the domes are perfect and smooth, and the gasket surface is the same.
You can have your stock head milled to get 170 psi, stock is around 150.

it wont change reliability really, if you run the proper fuel octane to deal with the increased compression.

 

[spence]

sent pm

 

[sjetrider]

Whoa whoa....slow down. That depends on many factors. 180-190 is fine on a stock or ported 701 Superjet without additional timing advance, reasonable squish, and good gas quality, all on an 81mm bore.

Change any of those, and you'll be in deto territory.

UR JUST SCEEEEEERED BRO, 180 to 190, mix right and roll w/ it. IMO :biggthumpup:

 

[spence]

aww no the doemes dont look god mouthfulloflake told me