Super Jet Anyone ever seen this?

[MADMAT]

I could tell I had a bad Oring on the head so I pulled the head and found that issue but I have never seen this. It is outside the combustion area and once the head is torqued down it shouldn't be an issue, right?

 

[MADMAT]

How far do I fill the dome when checking the CC's? Just the low area or all the way to the outer edge?

 

[MADMAT]

Or does anyone know what domes produce 185psi on a 718cc with no porting?

 

[txsuperjetfreak96]

I was getting round that compression with stock motor and ada 33cc domes

 

[Superjetjim]

33 or 35cc domes.

Yeah I had a dome on an ADA head go like that - but only when my builder made the O ring grooves larger to accommodate the O rings he had in stock, I took the boat on a 10x day skiing holiday and it failed on day one like yours. Holiday over for me, really pissed at him when he admitted what he'd done!

 

[TheBuzzard]

unless that outside ring is totally supported, especially where the end gap will be, the O-ring will push out and not seal correctly. its basically junk, unless you like pulling the head off all the time to replace 0-rings.

 

[MADMAT]

Ok thanks guys....I need a dome or a set of domes then!

Do I fill the dome all the way to the Oring groove to test CC's?

 

[MADMAT]

33 or 35cc domes.

Yeah I had a dome on an ADA head go like that - but only when my builder made the O ring grooves larger to accommodate the O rings he had in stock, I took the boat on a 10x day skiing holiday and it failed on day one like yours. Holiday over for me, really pissed at him when he admitted what he'd done!

Really!? That was very silly him!! Geesh!

 

[MADMAT]

I am getting 39ml when filling it all the way up to where it meets the head. Sound right?

 

[MADMAT]

Do I fill it with water all the way to the inner oring wall?

 

[BruceSki]

I would buy a set of domes and make sure your head is torqued properly. If that dome was chattering in there the head shell might be shot too. A new shell and domes would be the safest insurance. I'd go 33's on a ported motor. P

 

[feartheride]

u do need a piece of plexi glass to go over the dome I believe when measuring other wise it will not be acurate and yes fill the entire space

 

[MADMAT]

Ahhhh! To keep it from getting convex!? This makes sense! I'm gonna try again.

 

[DangerBoy]

Or does anyone know what domes produce 185psi on a 718cc with no porting?

35 cc

Db

 

[MADMAT]

35 cc

Db

Thanks all! I'm just gonna call Pro-tec and get a set or 2 on Monday. I can't be positive what cc I have here....it seems like 39cc but that doesn't seem logical.

I'm at 82mm Wisecos with stock porting.

 

[OCD Solutions]

What are the chances those are the same as Greater Yamaha, Blowsion or Riva domes? I have a set of 38cc 760 domes still in the Blowsion packaging that I will never use and will sell cheap. Should work fine in an over bore cylinder right?

Sent from a POS Galaxy S3 :banghead:

 

[MADMAT]

I think I need 82mm domes, no? 760 are the next domes up I think....for 85mm.

Someone correct me if I'm wrong and I'll take em!

 

[OCD Solutions]

How big of a hurry are you in? I can ship them to you to try, if they work, they work, if not, you'll have to order from Protec. Are you absolutely sure the Protec are the same as blowsion domes?

Sent from a POS Galaxy S3 :banghead:

 

[MADMAT]

Yes 99.9%! Not in so big a hurry I can't wait for em.

I'll PM you my addy....thanks man!! If its a no go I'll sen em right back! If they work I'll paypal you instantly!

 

[MADMAT]

Heres a pic Boyer....