1985 DT75 Suzuki - Need Help!!!!

[TimDollar]

1985 DT75 Suzuki motor runs real rough at low RPMs/Idle & in gear. It is so rough it shakes the boat. The higher the RPM the smother it runs. I just bought the boat so not sure how much it had been used. I checked the compression. #1 and 3 tested 150 PSI and #2 holds only 90 psi. It starts easy and stays running with no problems. It does push the 1972 16' Del Magic boat up to 40 MPH at over 5000 rpms. I am thinking of removing the head to look at the #2 piston/cylinder and replacing the gaskets. Any suggestions?

 

[rodbolt]

Re: 1985 DT75 Suzuki - Need Help!!!!

its blowed up.<br /> will never run correctly until you fix the cylinder sealing issue. continue running it while its sick will result in a permanent death.<br /> I agree the next step is to inspect the head,gasket and cyl. dont lose the pressure valve and spring when you take the head off.

 

[ROCKYW78]

Re: 1985 DT75 Suzuki - Need Help!!!!

Yes It Is I Have The Same Motor And #2 Is Ruined By Needle Bearing's Bouncing Around

 

[deejaycee_2000]

Re: 1985 DT75 Suzuki - Need Help!!!!

you would have to strip the whole powerhead, change the rings on the second cyl and get the crank balanced again .....

 

[Captain Mustang]

Re: 1985 DT75 Suzuki - Need Help!!!!

I had the same experience with my DT75. Blew a hole in top of piston #2. Had piston, rings etc replaced. Not sure if crank was rebalanced. Would this effect the way the engine runs at low revs if not done?