CMB 90

[nitro junky]

What % nitro should I run in a CMB 90?

 

[Ian Inverarity]

Nitro,

I dont run one, but as far as I know people use 40 to 50% nitro without problems.

Ian.

 

[nitrotoys]

From what i have read, Bigger the engine, LOWER THE NITRO. I wouldnt go over 30%. I have a 80 and run 20% and its just fine, Now the .21s like the high nitro.

run 20% maxxie through it and it will be just fine.

 

[zagustin]

Nitrotoys' recommendation is right. My experience with a bunch of CMB 90 is the same. More nitro is a waste of money and is related to a loss of reliability.

Werner

 

[Chris Attebery]

Guys,

I ran 40% to 50% in my K90s without a problem. 60% made the motor a real *****.

Run an MC9 and run it rich. You shouldn't have any problems.

Chris

 

[Ian Inverarity]

Personally I use 25% in my A-90HP and K-90, but I make the cyl heads to suit. I was merely suggesting that most of the CMB 90's I have seen are running 40-50%.

Ian.

 

[nitro junky]

thanks guys ;D

 

[paul heuston]

from my experiance my cmb 90 has run well on 20%nitro but a did have it going on 50% when i bought it then from bad tuneing i blew the rod but since running 20% and better maintance its a dream

paul

destroyer racing

"if it rattles when you pull it out then you broke it stupid!!!"

 

[[email protected]]

20% is just fine. If you want to look cool pour it into the 60% bottle laying around in your garage and lie to everyone that you only run high nitro. LOL

 

[Wild Bill]

I have been running CMB 90's in my twin for 2 years, I got out of Picco's because I couldn't get the parts I needed to keep them going. I run 50% and have since day one. In the two years I have had to replace only 1 piston. I do replace bearings about every 6 months as a precaution, doesn't everyone? By the way, the boat runs faster with the CMB's and seems to handle the water conditions better due to the extra weight.

 

[[email protected]]

You have to replace bearings? I'll have to remember that. LOL