Glad I found this before spring...

[nola mike]

Finally got around to winterizing the boat last week (I actually STILL thought about taking it out that day). Have had a leak at the exhaust manifold/riser junction because of a bad surface on the mani, so I had planned on machining it before spring. Got it started with a bit of difficulty after 2 months, but it was running. Pulled the riser/mani, and pulled the valve cover just to take a look. Glad I did. Plan on replacing the spring guide and spring. Any thoughts on what would cause this? Haven't messed around with the valves with the head still on. I don't have a fitting to attach the compressor to the cylinder--could I prevent the valve from dropping just by moving the piston to close to TDC?

 

[GA_Boater]

Re: Glad I found this before spring...

Old trick. Pull the spark plug on the bad cylinder and stuff a mess of clothesline down the hole- not all of it. Turn the motor on the compression stoke (both valves closed) until you can't turn it any more. Don't force it. Take off the rocker arm and compress the valve spring and fix he problem. After you're done back off the crank, pull out the rope and put the plug back in.

I hope that's the only problem. Hope the valve guide isn't shot. That valve seems cocked to the right.

 

[Jmunk]

Re: Glad I found this before spring...

These marine engines live most of their life near the upper RPM range and I have seen valve springs break before. The rope trick posted above will work fine, just feed the rope in with the piston down and after you get a few feet of rope in carefully roll the motor up to get the piston near TDC. I see your also in the Richmond area.

 

[etracer68]

Re: Glad I found this before spring...

Yes, it looks like the valve, and possible stud and push rod bent. I would be pulling the heads, and go through them completely. Just my .0002.

 

[nola mike]

Re: Glad I found this before spring...

Yes, it looks like the valve, and possible stud and push rod bent. I would be pulling the heads, and go through them completely. Just my .0002.

Push rod looked ok, valve moves no problem. Like I said, it was actually running OK before I pulled the cover. Thanks for the rope trick, I'll give that a shot for sure. Valve isn't cocked right, the spring is cocked to the left

 

[Glastron_V210]

Re: Glad I found this before spring...

you can also use compressed air through a spark plug threaded fitting. Works the sam eway, but no chance of particle intrusion.

Chay

 

[glastron09]

Re: Glad I found this before spring...

check the valve guide, probbaly worn

 

[marioc]

Re: Glad I found this before spring...

Push rod looked ok, valve moves no problem. Like I said, it was actually running OK before I pulled the cover. Thanks for the rope trick, I'll give that a shot for sure. Valve isn't cocked right, the spring is cocked to the left

Is this on your 470?

 

[nola mike]

Re: Glad I found this before spring...

Is this on your 470?

yup

 

[picklenjim]

Re: Glad I found this before spring...

I would try the air fitting in the spark plug hole first with the piston all the way up and the crank blocked somehow so it won't turn when you apply the air. Their very inexpensive. I've heard of the rope trick before but if by chance the rope gets tangled inside you will be pulling the head for sure than..

 

[ricovw]

Re: Glad I found this before spring...

Just curious as I read this thread. What does the rope trick do. I'm not quite understanding it.

 

[cr2k]

Re: Glad I found this before spring...

The coiled up rope will be "packed" into the compression chamber and keep the valve from opening or "hold it in the closed position" while you compress the spring release the keepers and replace it.

 

[nola mike]

Re: Glad I found this before spring...

The coiled up rope will be "packed" into the compression chamber and keep the valve from opening or "hold it in the closed position" while you compress the spring release the keepers and replace it.

although the more I think about it, it doesn't seem like there would be nearly enough room in the combustion chamber for the valve to fall with the piston at TDC, no?

 

[RogersJetboat454]

Re: Glad I found this before spring...

although the more I think about it, it doesn't seem like there would be nearly enough room in the combustion chamber for the valve to fall with the piston at TDC, no?

Even if the valve falls a 1/4" that can be enough to make it a real PITA to get the keepers back on. The rope trick will probably work fine. I have used it may times my self to lock a crank with no ill effect while removing/installing crank bolts.

 

[nola mike]

Re: Glad I found this before spring...

thanks for the tip guys. Worked great. I always thought the problem was losing the valve into the cylinder. The problem is actually that if the valve isn't all the way closed it would be impossible to remove the keepers. Anyway, the spring was broken at the top. Valve doesn't appear to be loose in the guide. Didn't range it much though, as I started to unscrew the stator bolt when I tried to back the crank the other way. It was too damn cold to spend much time messing with it.

 

[GA_Boater]

Re: Glad I found this before spring...

Glad it worked for ya, nola. Pull out all the plugs if you haven't. Compression might be making the crank hard to back off.

 

[nola mike]

Re: Glad I found this before spring...

yeah, I'm not too worried about that part. I think this is the second time in 2 years that I've dodged a bullet with this head. Still wondering what caused this. This isn't helping my fear of a catastrophic engine failure leaving me stranded. Took me weeks at the beginning of this season before I'd venture more that a few miles from home. Here's the spring off: