Head

[sxrcohen5]

What would you guys recomend for a head for a yamaha 701?..trying to find somehting best for freestyle and resoanable priced ...thanks

 

[adet16v]

try to get a girdled one, more expensive but safer for the cylinder (cracking)

make sure to get one with removable/interchangeable domes

 

[#ZERO]

I would go with a Riva or ADA girdled head with 35cc domes. :biggrin:

 

[ANT]

The ADA looks soo good under on the motor...o ye it works well and seals well to. I don't like how you have to cut your own outer o-ring with the riva although it is also a good head

 

[Mark44]

PM Katie she just got a great deal on an ADA head I don't know who she purchased it from but they are new and at a great price. She also has a head for sale.

Mark44

 

[SUPERTUNE]

ADA all the way, the only exception would be if your building a 86-86.5mm big bore, then use a R&D or Riva as they use slightly larger O.D. domes and have the dome sealing o-rings moved out to allow the bigger bore to seal well...

 

[superjet0587]

is the girdled head necessary on the stock cylinder

 

[thegoldenboy]

No it is not necessary on a stock cylinder. Its never a bad idea though.. I believe they were initially introduced for bigger built motors. Now that has trickled down into the recreational heads as more people are building better motors and want added insurance.

 

[yamanube]

I also thought it was wierd that you had to cut the outer o-ring on the ADA head, it seems like for the price you pay they should come precut at the right size.

 

[JetSkiJunkie]

is the girdled head necessary on the stock cylinder

61x cylinder? Definately!! If you raise the compression, (and why would you get an aftemarket head if you were not?) you better get a girdled head!! The 61x cylinders hava tendency to crack near the base of the cylinder on the intake side.

I bought a blaster with a Riva non-girdled head, and it now has a cracked cylinder. I got it welded, and am either going to switch to a gidled head or get something like the Pro-Tec half girdle kit.

 

[douglee25]

This is what happened when I didn't run a girdled head last summer. Kiss this ported cylinder goodbye!

Doug

 

[michael950]

:bigeyes:

 

[douglee25]

Needless to say, my ADA head is on the way. :smile:

Doug

 

[demolition_x]

is that from some heavy wave jumping and that heavy red pipe?


i never knew it would crack that bad.

 

[meatball]

Yea what comp were you running and what were you doing?

 

[douglee25]

To make a long story short, that motor had the riva red pipe on it. I was running the protec rec head (175 psi, 35cc domes). I never had a problem with detonation, etc. The pistons looked brand new when I pulled them. Anyway, I pulled the head to look into a cooling issue I was having. Upon sealing it back up and torquing the head bolts, I heard a snap?? I thought I snapped the bolt. When I backed it it out, the bolt came out in one piece? WTF I thought? I proceeded to back out the rest of the bolts and when I took the head back off, I could see see the casting had cracked on the head sealing surface. Then I looked at the side of the cylinder and that's when I cursed the hell out of ski!! That cylinder didn't have more than 2 seasons since being bored and ported.

Doug