- Location
- Ocala florida
I am a newbi I have 8701 super jet West Coast head it says YEP7030 Trying to find out what size domes they are in how much compression
Superjet westcoast head help!!!!!!
- Thread starter Bikerant83
- Start date
john zigler
Vendor Account
- Location
- wisconsin
The domes should have a number on them, near where the plug mounts. You may need to remove them to see the number. Number would be the size of the domes in CC's. Some of the early heads/domes did not have numbers, and in that case the only real way to tell is by CCing them.
- Location
- Ocala florida
It says yec 7030
john zigler
Vendor Account
- Location
- wisconsin
OK, then those are 30cc domes. I cannot remember the Yamaha Part numbers, and would recommend measuring the chamber Diam. 701cc should be about 82mm. If they are 701 domes, compression is going to be in the 220lb range.... Race gas for sure...
- Location
- Amherst NH
I dont think 30s are that high.
- Location
- Ocala florida
It doesnt have removabke domes
- Location
- Amherst NH
Picture?
- Location
- norfolk country
i just bought one of these and you have 30cc domes but you have to use a stock head gasket which adds about 5 to 6 cc so really your at like 36cc and should be between 170 and 180 psi. you are fine to just bolt on and run on pump gas 91 plus
john zigler
Vendor Account
- Location
- wisconsin
I was using the ADA Chart, with 30cc domes. Pineapple is right, if you are using a stock gasket that is going to add CC'a and a lot of volume. That would lower compression considerably. I am more familiar with the Westcoast Kawi head which uses a special very thin gasket. I am unsure on the Yamaha if you use a special thin gasket, or thick OE type.