71'Thunderbolt
Recruit
- Joined
- Aug 22, 2007
- Messages
- 4
Hey everyone.. i am a little new to the whole outboard scene. I know my stuff when it comes to engines and such things and need some help.
I have a 1971 1350 mercury straight 6 135 hp, starts and runs great... but the problem is that when i give it full throttle it boggs down and wont go any faster. I have done some research and found that cleaning out the carbs would most likely fix that problem so i went to go do a compression test to see what i was working with... now the top #1 had like 130, #2 had 120 . #3 had 0...!!!!!... #4 had like 130..#5 had about 130... #6 had 135
now i read some more fourms and got some de-carb and sprayed it in the #3 cylinder and set it over night... went out the next mornin and nothin.... the needle goes up to about like 5.... so i put some straight weight oil in it and the compression went to about 60 the first time and the second time 90....
i also tried to tap the top of the piston with a wooden dowel to break/shock the "stuck" ring free.. and stll nothing... so i ran the engine and put the whole can of de-carb in it... and tried it again and still like 0 compression...
i also filled the other pistons up with the decarb with spark plugs out, and cranked it over to see what it would do and i got about 10+psi out of each cylinder except #3
so i need some help because this is just killing me and i dont want to take the entire engine apart for 1 piston... so please give some advice... i tried to give as much info as possible to narrow down the possibilities... thanks for reading...!
O .... and also... is there a themostat on my engine because i have read that they might get stuck and the engine can overheat?... so... any advice would mean a great deal.. thanks!
I have a 1971 1350 mercury straight 6 135 hp, starts and runs great... but the problem is that when i give it full throttle it boggs down and wont go any faster. I have done some research and found that cleaning out the carbs would most likely fix that problem so i went to go do a compression test to see what i was working with... now the top #1 had like 130, #2 had 120 . #3 had 0...!!!!!... #4 had like 130..#5 had about 130... #6 had 135
now i read some more fourms and got some de-carb and sprayed it in the #3 cylinder and set it over night... went out the next mornin and nothin.... the needle goes up to about like 5.... so i put some straight weight oil in it and the compression went to about 60 the first time and the second time 90....
i also tried to tap the top of the piston with a wooden dowel to break/shock the "stuck" ring free.. and stll nothing... so i ran the engine and put the whole can of de-carb in it... and tried it again and still like 0 compression...
i also filled the other pistons up with the decarb with spark plugs out, and cranked it over to see what it would do and i got about 10+psi out of each cylinder except #3
so i need some help because this is just killing me and i dont want to take the entire engine apart for 1 piston... so please give some advice... i tried to give as much info as possible to narrow down the possibilities... thanks for reading...!
O .... and also... is there a themostat on my engine because i have read that they might get stuck and the engine can overheat?... so... any advice would mean a great deal.. thanks!
