Yamaha 701 x 760 domes

[geraban19]

Guys,
I have a TLR 701 light ported that I disassemble to rebuild and realized that the piston was touching the domes a little bit.

Pistons are 83mm and domes are 701. Squish wasn't right, obviuosly.

I was going to machine domes but I have some 760 domes.

Question is if when running 83's on 701 cyl you better run 760 or machine 701??

Thanks for the help.

G


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[All stock 701]

What size domes do you have and what kind compression are you looking for?

 

[geraban19]

I have 33cc (701) and 35cc (760).
Due to the problem (no squish), I was getting 225psi w/33cc(701)...
Looking for 185/195.


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[Big Kahuna]

You can run up to 83-84mm bore with the 701 Domes. Sounds like you have a cylinder that got decked a bit more than needed or decked on purpose to correct some issues. Or you have a thinner base gasket. I would try the 760 domes and measure squish.

 

[geraban19]

Thanks BK.
Cylinder perform good and I realized the issue when disassemble to inspect it.
It was running strong.
Maybe another gasket will do the job or a dome machine service to get correct squish.
Compression was crazy... 225psi w/33cc domes.
Btw, we rode it for a couple of years like this.


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[Big Kahuna]

Wait, you should be running more like 35cc-38cc domes for pump gas.

 

[Big Kahuna]

At 82-83mm bore with my TLR I use to run close to 200 lbs at sea level with 35cc domes.

 

[BruceSki]

I believe you can use760 domes starting at 83mm bore

I'm at 215 @82mm bore on 33cc 701 domes.

 

[All stock 701]

At 83mm pistons you are running a 735 not a 701. That is why the 701 domes are hitting the pistons.

 

[geraban19]

At 83mm pistons you are running a 735 not a 701. That is why the 701 domes are hitting the pistons.

So you agree to run 760 domes??


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[Big Kahuna]

At 83mm pistons you are running a 735 not a 701. That is why the 701 domes are hitting the pistons.

Incorrect.
ADA Racing billet dome includes compression(OR043) and dome top(OR020) orings. Squish relief is .015 inch @ 83mm with a 10.5 degree angle.

AVAILABILITY:
In Stock.

FITS THE FOLLOWING:
Yamaha 1100/1200 - Yamaha 701


Domes for 701's are cut to 83mm. This means they work on 81-83mm bores. If his piston is hitting the domes, then his cylinder has been decked or he is not running a base gasket.

 

[geraban19]

Incorrect.
ADA Racing billet dome includes compression(OR043) and dome top(OR020) orings. Squish relief is .015 inch @ 83mm with a 10.5 degree angle.

AVAILABILITY:
In Stock.

FITS THE FOLLOWING:
Yamaha 1100/1200 - Yamaha 701


Domes for 701's are cut to 83mm. This means they work on 81-83mm bores. If his piston is hitting the domes, then his cylinder has been decked or he is not running a base gasket.

You are right as it is hitting not on the borders...
Maybe an excessive deck service or thinner gasket.


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[JetManiac]

701 domes 81-83mm

760 domes 84-86mm

We have custom thickness base gaskets 0.020"(stock) to 0.060". Otherwise you can more squish, but remember that compression will rise if you run piston higher into the dome.