Need Advice on Engine Issue

[ribcage]

First of all I love this sight. During the rebuilding of my boat I used it many times. But here is the issue I am having. Just got my 1991 Bayliner out of the shop because it was not firing on the 1 or 3rd cylinder. They said it was fixed and that it would be fine. Took it out to the lake and it started fine. I ran it an hour or so and stopped. After I stopped I think we got caught in the mud and when we tried getting the engine started again it was very very difficult. It would almost not start at all.

While finally barely got back to the dock and when I hooked it up to the ear muffs it was very difficult running. I would disconnect only one of the three cylinders and it would completely die. I ended up removing each spark plug and noticed one has been damaged. I reviewed the inside of the cylinder and it looks rough. Please give me your thoughts and if I should take it back to the shop, something is wrong. Included pics

1991 Bayliner
90 Horsepower force 3 cyl

 

[Jiggz]

Re: Need Advice on Engine Issue

That's one rough looking plug and cylinder. I doubt the mechanic will take responsibility for whatever damage is sustained because the engine was running correctly when it was taken out of his shop. However, since it is on the same cylinder when it was first sent to the shop you can try but again I doubt he will do it for free. From the look of that plug and cylinder it looks like a bad fuel recirc system or improperly set carb. If the mechanic refuses to take responsibility you can still fix that on your own easily. But first take compression test of all cylinders first. If they are good, most likely there is no damage to the piston and cylinders and you only need to clean the 3rd cylinder and do proper adjustment of the carb or fuel recirc system. Another thing that could also be wrong with this cylinder is bad reeds, but you should be able to see that with fuel blowing out of the bottom carb.

 

[Frank Acampora]

Re: Need Advice on Engine Issue

Much as I would like to diss the mechanic, I can not, unless he messed with the carbs.

Your engine has most likely broken a ring and the pieces banged around inside the cylinder for a while before blowing out the exhaust ports. You will see the same denting on the cylinder head. late model Force engines with semi-keystone top rings frequently do break those rings for no reason. In the process, the piston is destroyed at the ring lands where the ring broke.

You need to remove the head and inspect the affected cylinder to see how much damage has been done. It is almost certain that the piston will need to be replaced and there is a reasonable chance that the cylinder will need boring oversized.

Edit: It might have also eaten a reed petal instead of breaking a ring. Remove the affected cylinder carb and check the reeds. If there is one or more broken or missing, then usually there is no cylinder damage and the reed(s) can be replaced easily.

 

[ribcage]

Re: Need Advice on Engine Issue

Yes the mechanic did mess with the carbs when it was taken in. They were completely out of sync when I took it in.

 

[Jiggz]

Re: Need Advice on Engine Issue

Rib, you need to converse with your mechanic with the status of your engine and ask if he is going to do anything about it as a part of the warranty work. Goodluck. And if you decide to do the work yourself, continue to post and the forum will gladly help. For now there is very little we can achieve since you are now in limbo. For as soon as you decide to remove that head or carb, your mechanic will find every reasons not to even touch that engine again.