1997 Honda 25hp 4stroke problem

So I got around to tearing in to this thing and I pulled the head to see what the valves looked like and when I looked at the pistons there was a slight shiny spot on each of the relief ports in the piston so I thought I'd better pull the valves out on the intake side since that's the ones that had the shine and rolled them on te table and to my suprise they rolled good. I got looking at the head and decided to pull the cam gear and noticed the key way was damaged a little and then it hit me. The other day I was looking at the engine and I seen this little round piece of metal laying there and didn't think much of it and almost threw it in the trash but instead I left it lay in the bottom of the engine in case I found where it goes some day. Well today was the day I found where it went. I figured out the problem was the key fell out of the key way and that's where the no compression came into play

Thanks for the help everyone

It always feels good to find the definitive answer. Keep us posted on your results - but sounds like you are well on your way to a healthy engine. Nice job.

Opps! Forgot about the key on the cam. The one on the flywheel is the one that normally sheers.

Glad the valves are not bent.

Now let's hope your water situation is resolved. The water in cylinders probably caused the key to sheer.

Keep us posted.

Mike

so i called and talked to a parts guy at a boat shop and he said im going to have to spend a $1000 or more to rebuild the head. why the heck would that be? cant i just put a new cam in it or should i just put a spot weld on the cam where it wore into the key way on the cam?

The way I see it, it's 220.25 + shipping and any applicable taxes. That's the total cost of the new cam with key, head gasket and oil seal from boats.net.

Or, you could weld it up if you make sure you get it right the first time but for $163 and change, I'd go for the new shaft and be done with it.

That's what I was thinking to but the guy said I'd have to grind the valves and a bunch of other stuff. I don't think he knew what he was talking about. Parts guys

Well I put a small weld on it and put some red lock tight on it so hope it works

I have another question. I put the head back on just to see if I had compression and I do the #1cylinder shows 185 #2 shows 155 and #3 shows 180. Why would number 2 be so much lower? I didn't put a new head gasket on would that be why. I know someone's going to tell me I have to put a new one on but I just wanted to check to see if it would have compression

It COULD be the gasket. Or, it could be something else. Here's where the leakdown tester would really come in handy.

You might try squirting some oil in the cylinder with the motor tilted up as far as you can get it. This helps spread the oil over the top of the piston, Then, recheck compression and see if it comes up significantly. This is called the "wet" test and an increase of around 15% in pressure would indicate the rings aren't sealing well.

i did the wet test and it bumped up the compression to the 185 range so what does that mean

Well, I guess you are talking about cylinder #2 as the others were already at that pressure. That is a significant increase (around 19%) so that would indicate that the compression ring is leaking on that cylinder and that is where the compression is going low. Right into the crankcase.

It's not all that unusual for those types of problems to show up in a "middle" cylinder before the outlying cylinders.

The inner cylinders typically run a bit hotter and wear sooner than the outer ones because it's harder to remove the heat due to the location in the block. Or, it could be a problem that was created when the engine got a gulp of water. It could have cracked the ring or broken a small piece of ring land off of the piston when it tried to hydro-lock. Hard to say without a visual inspection.

That large a difference will cause an imbalance in the way the cylinders work together. and, if you do have a broken piece in there, if it works loose it could be fatal. You might want to consider doing a ring job before running it hard again. And, if the pistons have to come out anyway, then that's the time to do main and rod bearings as well.

Sorry to be the bearer of bad news but now you know.

well I just got back to working on this motor and heres what I did. I rechecked the timing and that was correct. I checked the valve clearance and found #2 was a little tight so it might have been hanging open a little when I did the compression check (haven't rechecked compression). so now this I just tried running it at first without the hose hooked up and it ran fine. then I went out and hooked it up to the hose and it runs like crap and now I have all kinds of water in the oil. I assume I have to pull the head off and put a new gasket on or is there something I might have missed?? I can not remember If I put a new gasket on last fall or not. I don't think I did because I wanted to see if it would run and nothing internal was damaged.

Not sure what you mean by..."I just tried running it at first without the hose". You ran it dry?!!? You can't run one dry for even a few seconds or you'll "wipe" the water pump impeller.

If you go back and reread your post (as I just did) you stated that you DID NOT put a new head gasket on.

Would u say its getting water in the oil because I didn't put a new gasket on?

That would fall under "most likely" for sure and, if it were me, I would put a new one on, torque the head properly, and try it again.