Something's burning...!

[TRIP]

Hey all,

I just changed the distributor, and belts, boat (with GT40) has been running fine. However, since changing those, there's always a smell of something burning when the engine is running, perhaps rubber. Can't find exactly what or where but it's somewhere near the distributor, near the belts, waterpump side. If my nose is right, at least

I think that timing might be a little bit off; from what I read here it should be 5 degrees before TDC and the mechanic said he'd put it at 0 degrees.
Could timing being off a bit cause anything to heat up excessively..?

A friend suggested it could be the big (exhaust?) hose, from manifold to damper...
Since it started right when the distributor was changed I figured it had something to do with that, but perhaps just a coincidence and it is something else?
If that big hose, would that possibly the impeller going out? Was about to change that anyway, but what else to check?

Thanks!

[NautiqueJeff]

What's the engine temperature? If that's fine, then I would look somewhere other than the impeller.

Are the belts set to the correct tension (not too loose or too tight)? A slipping belt would smell like burning rubber.

[TRIP]

Yeah, sorry that I forgot to mention, but engine temp stays fine.
Belts I feel are not super tight and definitely not too loose.

Thanks!

[TRIP]

It's definitely the exhaust hoses burning and smelling. Odd since engine temp stays fine!
Changed impeller (still looked like new), and port side is better now, starboard is still too hot to touch (not even 1 sec) and keeps burning.
Checked the hose from thermostat to manifold and a little rust came out, a bit or orange dirt stuck to the inside, but that didn't help making it any better.
T-stat housing probably has a gasket? Not sure if I'd be able to find locally... Or is it a common automotive part?
I tried getting the hose lose from manifold, not sure that's even possible without just cutting it open, so tight!

Any recommendations or tips..?!
Thanks!

[charlesml3]

There's a clog somewhere. If one side is cool and the other is hot, it isn't getting enough water. Most likely this all started when the impeller shredded.

-Charles

[TRIP]

Well the impeller wasn't damaged at all, so that's not what's causing it, but yeah it's clogged somewhere. Rust probably.

Planning to take both hoses from T-stat to manifolds off, run into buckets and run engine for like 2 seconds.
If they're spewing out more or less the same amount of water, do the same thing at the end of the exhaust hoses, both sides.
That way I could see if there's an obstruction somewhere, and whether before manifold or inside it /in riser.

Other ideas and tips are welcome!

[TRIP]

Well, did test output of hoses to both manifolds, and was the same both sides. So must be manifold and/or riser that's bad.
Tried to get the exhaust hose off on the bad side, sprayed some wd40 in between riser and hose. However: there's never enough space to move that hose enough to get it off, is there? And bending it isn't happening either. Do you have to get the muffler off to get the hose off?

[wtrskrs]

Well, did test output of hoses to both manifolds, and was the same both sides. So must be manifold and/or riser that's bad.
Tried to get the exhaust hose off on the bad side, sprayed some wd40 in between riser and hose. However: there's never enough space to move that hose enough to get it off, is there? And bending it isn't happening either. Do you have to get the muffler off to get the hose off?

If you can take the riser off the manifold (four bolts), you can then twist the riser to pull it off the exhaust hose. Use lots of PB Blaster or better fluid on the bolts and let them sit for a while. When I removed mine (replacing with new GT40C heads), one of the long bolts sheared off. A major hassle to get the stub out.

[TRIP]

Pulled the drain plug on the manifold (why hadn't I done that any earlier?!) and lots of dirt and little rust parts came out. What's best way to flush them, and risers?

[TRIP]

Quite a bunch of dirt and rust came out, however hoses and risers are getting too hot to touch in less than 3 minutes of running the engine. [:^(]
Time to order gaskets and screws, and take risers and manifolds off for a good cleaning. That's normally done in an acid-bath I think?

Also, after putting everything back together, water was leaking from both sides of the exhaust hose. Can't/don't want to tighten the clamps any more. Should some gasket-like material go in there? Didn't notice any when pulling them off.

Thanks!

[TRIP]

So how did it go for you gun-driver?

I'm puzzled: took risers and manifolds off. Didn't look all that bad, not very rusted. Cleaned them out with high pressure water, metal wire, and tie wraps (in on one side, out on other. Worked amazingly well!). Couldn't find muratic acid around here unfortunately but gave 'em a pretty good cleaning I feel.

Put boat back in the lake today, one hose stayed just warm, other got friggin' hot again while just idling with boat on trailer.
Decided to do a quick wakeboard set (15 min) to see what would happen after running some more and higher rpm's; when we were done both were just fine! Idled back to the dock, and now BOTH were way too hot again!

Again: engine temp stays perfectly fine.
Anyone can explain this?
T-stat? RWP? If one of those would be going bad, wouldn't engine be getting hot too?

[zoah]

There is an upper and lower thermostat housing. I'm willing to bet that the upper housing holes leading to the manifolds is clogged with rust or debris. I'm shocked that your T-stat is opening and closing. When I took mine apart there was a ton of rust within the upper housing. Clear as much as you can and re install.

Be cautious investigating, because it sounds like the upper and lowers are no longer available. Skidim has a replacement, but it is pricey!