91 135HP POWER QUESTIONS/ PROBLEMS

Mike Caspari

Cadet
Joined
May 8, 2005
Messages
21
I have a 24 foot CC with twin 91 135's and I think I may be having trouble with both of them.<br />The boat weighs around 4500lbs(in theory)and will run about 43 mph on 17p props. Last year one motor would get it on plane but this year don't seem to have the power. They both sound the same and have the same power, just not like before. The plugs are a year old and I suspect a few of the plug wires on both motors as needing replaced(the ends got pulled out and I jimmied them back together). I checked all the electronic modules last year(stators, triggers, switch boxes.)<br />How fast should this boat run on those 17's? One motor would get it on plane last year but it took a while(2 people, light fuel and load), is this expected? Compression is around avg 117lbs.<br />I Know I need fuel water seperators and have kept a close eye on the amount of water in the tank, I would drain the bottom to remove most water. I have had tank problems due to one 3/8 pick up and a "T". The motors weren't run hard in that configuration.<br /><br />I plan to run the water seperators this weekend and tune up the motors. I will check the plugs for consistency after the first run this weekend. I have since installed an extra tank to seperate the motors until I can add a pickup to the tank. Fuel pumps were replaced 2 weeks ago. What else can I check? What can I run through the fuel to clean up the system?<br /><br />Don't want to ruin a power head!!!
 

Mike Caspari

Cadet
Joined
May 8, 2005
Messages
21
Re: 91 135HP POWER QUESTIONS/ PROBLEMS

Found a plug wire pulled off one of the engines. Looks like a complete tune-up is definately in order.
 

Coolmaker

Petty Officer 2nd Class
Joined
Mar 15, 2005
Messages
134
Re: 91 135HP POWER QUESTIONS/ PROBLEMS

Sounds like it might be time for a carb clean too.... Those old motors are strong when tuned right.
 

Mike Caspari

Cadet
Joined
May 8, 2005
Messages
21
Re: 91 135HP POWER QUESTIONS/ PROBLEMS

I run a little sea foam through the carbs but maybe I should run a treated tank through each motor. I put about 60 miles on it over the weekend so now I need to recheck the new plugs for consistency/inconsistency.
 
Top