exhausts on outboards

[trev1]

I pulledthe leg off my outboard yesterday to do the waterpump and found a length of 50 - 60 mm tube between the two sections when I seperated the leg. It has rusted off from the powerhead I think , should I be concerned about it??
P.S. I think it is just an exhaust extension and it still runs OK

[Roughasguts]

So that there tube ! Just wondering if the end of that tube has to go to your water pump and the other end to your power head ? I know you said 50-60 mm but is that lengh, or diameter ?

Cause if that tube is for your water pump to power head then yep you need a new one.

What motor ?

[trev1]

nah, not the waterpump tube, that went back in when I refitted the leg and it pumps water now as well . It is 50 -60 mm dia by about 170mm long. I'm pretty sure its an exhaust extension

[FNQCairns]

What engine is it? there are a few place on the net that display schematics, someone may know of a site for yours.

cheers fnq

[Roughasguts]

Thats okay then.
But then that pipe has a few uses one is exhaust gases, the other is to keep the hot salty water of your internal linkages, seals and shafts etc.
Think you might wan't to take another look at replacing it if things are going to rust up because it's no longer there.

[BM]

Has your engine been converted from L to XL by chance?

[trev1]

Engine is a 50 4 stroke yammie 97 model. as best as I can see it hasn't been changed short to long as its a short shaft (standard length ) anyway. The top of the pipe has a definite "rusted off" look about it. I had a look up the leg and couldn't really see much, but I could see a piece of pipe coming down from the powerhead and I reckon the peice I took out is the other end of it. It looks about the same dia. I just want to know if there is any damage to be done with it not completely there?? It also probably hasn't been there for a long time, its been 2 years since I bought the boat 2nd hand and the first time I have had the leg off

[BM]

Trev,

I think you'll find its this part:

62Y-41131-00-00 Manifold, Ext.1


http://parts.yamaha-motor.com/partimage.gifx?d=80770,2,0

The exhaust mainfold extension (part 3). Roughly triangular in shape at the top and bolts in with 3 bolts.

Going to cost a bit to repair.

Cheers

[trev1]

part no 3 on the diagram . That'll be a powerhead off which means gaskets ect. I think its been there a while as it had worn a cuople of grooves inside the lower leg where it had been sitting. It had rubbed away about 2 mm of alloy (looked like a machined area for the tube) where it had been sitting.

[BM]

Probably take about 1 day to do a repair like that. Being a Yamaha that will be an expensive part. Probably $300-500 as a starting point.

Cheers

[trev1]

It'd just be there to stop water going back up into the cylinders I'd guess. I would be doing the repairs myself (I'm a diesel fitter 15+ yrs) and I think I would visit the local exhaust shop to get a bit of stianless pipe to put on the flange and just buy the gaskets. I just dont know if I need to seperate the oil pan to gain acess to the flange. (if I do the job)
I justhad a good look at the piccy BM , it shows 2 distinct bends, I only have 1 bend so I'm guessing I have only lost 1/2 of the part. I may see how it goes as its probably been like that the whole time I've had it.

[BM]

I haven't pulled one of those apart as yet but I stripped a late 90's 4 stroke 60 Merc a short time ago and yours will be similar. In fact at that time the Merc 4 stroke was a Yam.

Drain the oil and pull the 2 plastic covers off the midsection to expose the powerhead bolts. Undo all powerhead bolts, shift assembly and all external cables and looms.

Cheers

[trev1]

Thanks BM. I dont think I will have any trouble except for finding a suitable tree to lift the powerhead with.