Rebuild motor? Check my pics

ebsworj · May 21, 2005

I have a Force 1994 120 HP that seems to be under powered recently. I did a compression test and it has a low cylinder on the one nearest the top of the motor. ITs 150 vs 170 for the other 3. I pulled the head to look at the cylinders expecting to find scoring or scratches but saw nothing differnt from the other cylinders which looked fine. What could be my problem? Am I going to have to rebuild my motor even though my cylinders look good? Check my photos in the link below. Thanks Photos of motor

22trophy · May 21, 2005

Re: Rebuild motor? Check my pics

excellent job on the photos!

zindale · May 21, 2005

Re: Rebuild motor? Check my pics

i have a 89 150 looks like mine did a month ago tore mine down had broke rings. rebored and rebuilt.

Realgun · May 22, 2005

Re: Rebuild motor? Check my pics

I would run some seafoam through that motor and have the upper carb rebuilt. It seems to be carboned up a bit and the 175 cylinder is a bit too. I wonder if the bottom has a water leak due to the two bottom cylinders being so darn clean.

ebsworj · May 22, 2005

Re: Rebuild motor? Check my pics

Maybe its hard to see from the photos but the cylinders look almost identical. I wiped some crud out from they cylinders that fell in when the head came off... could explain their clean apperance. Do I have to buy a kit to rebuild the carbs or can i clean them with a product?

novicetech · May 22, 2005

Re: Rebuild motor? Check my pics

Did you try retorque head bolts before you pulled the head?

ebsworj · May 22, 2005

Re: Rebuild motor? Check my pics

head is tight... tried sea foam still runs funny

ebsworj · May 22, 2005

Re: Rebuild motor? Check my pics

novicetech · May 23, 2005

Re: Rebuild motor? Check my pics

You could try removing the exhaust plate and cover and then with a piece of brass or aluminimum and depress the rings and see if they are stuck\ broke on the low piston. I have never tried this myself but i have heard of people romoving just the bad piston honing and new rings. But to me it seems that rod bearings would be very hard if not impossible to reinstall.

byordy · May 25, 2005

Re: Rebuild motor? Check my pics

The low cylinder and the one next to it look much to clean to me. It looks like you have water in the top and some, but less, water in the one next to it. The pictures don't really show a head gasket problem, but I would replace it (the head gasket), run it, and see what the compression does.

Docdoc · May 25, 2005

Re: Rebuild motor? Check my pics

You might want to re-surface the head while you are replacing the head gastket. Also, did you check for good spark in those top two cylinders? You are not much off of the +- 10% needed in all cylinders.

ebsworj · Jun 1, 2005

Re: Rebuild motor? Check my pics

how can I check for spark without shocking the beejezus out of myself?

bnk999 · Jun 1, 2005

Re: Rebuild motor? Check my pics

wrap a piece of wire around the threads of your spark plug then wrap with electrical tape and ground that wire to a good place on the block

Rebuild motor? Check my pics

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