How bad is it?

[kkuhia]

Alright, I finally got my parts (exhaust manifold and tilt unit) and installed them. I changed all the fluids in the boat (including the gas). I was running the engine on muffs after an oil change (to get any water out of the oil) and it ran very smooth for about 10 minutes. I was just about to turn off the engine (to change the oil again) when it died. The timing belt had come off! It didn't look like it broke. What would cause it to come off? Is it very difficult to fix? There does appear to be a little rust on a couple of the pulleys that the timing belt goes around.

Also, and I think this is the worst of the two, I was looking inside the valve cover to see if there was any forthy oil and I noticed what looked like a few little rust spots on a couple of the cam shaft lobes. How bad is that and what does that say about the rest of the engine? Am I just wasting my time on this thing?

There is some rust on some of the outside of the engine (on some of the gears and pulleys on the front of the engine). Compression check looked pretty good (160, 165, 165, 170), but it seems like if there is rust on the cam shaft lobes, wouldn't there be rust throughout the engine (block, etc)? I'm not quite sure what to do next.

 

[Reel Poor]

Re: How bad is it?

If the belt didn't break or strip any teeth off of it, there is a possibility that the belt tensioner failed.

Here is a pic of your setup.

 

[kkuhia]

Re: How bad is it?

Thanks for the pic ReelPoor...so do I have to pull everything off the front of the engine to check/fix that? There is a little rust on the gears (#s 18, 19, & 20 in your pic) is that a big deal and what do you think of the rust on the cam lobes?

 

[kkuhia]

Re: How bad is it?

The timing belt actually did break so it will need to be replaced. Looking at the manual it looks a little complicated given all the timing that needs to be lined up. Is it really that difficult and do I need special tools?

Anyone have any advice on rust on the cam shaft journals? It looks like all the journals have small spots of rust here and there. Does that mean the rest of the engine probably has rust in it? What do I do about that?

 

[Reel Poor]

Re: How bad is it?

Since the belt broke you need to make sure all the rotating componants will still turn, ie. cam, tensioner, and counter balance shaft. If one of these froze up it could be the reason for the broken belt, other reason, old age.

As for the rust on the cam, not a whole lot to do with it short of replacing the cam. If it's just some light surface rust it probably won't cause a problem. If it's built up rust deposits the cam would most likely suffer premature wear.

No special tools required. The pullys have marks on them that have to be alligned with their corrosponding marks on the engine. Not really a difficult job. Just remember, once you get the belt on, and all the marks are properly aligned and tensioner tight, rotate the crankshaft two full revolutions back to TDC and make sure the marks are still properly aligned.

 

[kkuhia]

Re: How bad is it?

I pulled everything off to allow me to replace the timing belt. Looks like the impeller got jammed in the raw water pump and that is what stopped the accessory drive pulley and broke the timing belt.

Here is my question now:

All of the gears and pulleys have some rust/corrosion on them (3 timing belt gears and crankshaft pulley - see pic below). Should I just lightly brush them and then ignore what I can't get with a wire brush or should I pull them off and get them sand blasted or cleaned up somehow? Seems like the camshaft and crankshaft gears/pulleys are easy to get off as they don't turn, but how do you keep the accessory drive gear from turning freely when trying to loosen the nut?

 

[Reel Poor]

Re: How bad is it?

From what I can see, the timming dears don't look to have any damaging rust problems. Clean them as best you can and install the belt.

As for the lower v-belt pully, it looks like it could stand a cleaning. Coulpe of choices, remove and sandblast, or a wire brush on it while the engine is running (I didn't say that did I ? :%) with the v-belt off, then some paint.

This strap wrench would be the best idea for for holding the balance shaft gear for removal.

 

[Mahoney]

Re: How bad is it?

Yah, I have seen engines in a lot worse shape than what you got there and they run just fine.

Good idea while you have stuff accesable to give ema good cleaning though.

 

[kkuhia]

Re: How bad is it?

Thanks for the replies! I have to admit that I already wire brushed the lower gear that you can see in the pic (thus the difference between it and the camshaft gear).

As for wire brushing while running, can you run the engine without the v-belt? Wouldn't that be bad as the water pump won't be connected?

If I remove and sandblast the pulley, how do I make sure it goes back on right so that the timing is still accurate?

 

[Reel Poor]

Re: How bad is it?

When you get the timming belt installed, turn the crankshaft two complete revolutions back to TDC. Recheck timming belt tension and make sure all your timming marks line back up they way they should be. If your satisfied the belt is installed correctly, start and run the engine for a brief period (15 to 20 seconds) before reassembling anything else, i.e., covers, pumps, v-belts, ect. This would be a great time to be ready with a wire brush or emery cloth (80 to 120 grit). This will also let you know if installing all the rest of the parts (previously removed for access) will be a waste of your time or not.

 

[Tally Ho]

Re: How bad is it?

Almost the same thing happened to me! My belt jumped off because the tensioner pulley nut was loose. My timing belt sheaves look even worse than yous but I think that they will still be okay with a little clean up.

Notice the pile of rust in the bilge...

I still need to strip the cooling components off the front of the engine. How much work s that?