It was all going so well

[Dan Gurney]

Ok, so finally I have the leg back after getting all the various bolts drilled out and the hole retapped/helicoiled as appropriate. The parts are on order so I'm almost ready to complete this job.

I have a question though: in the first pic of the original post you can see there is quite a lot of pitting along the mating surface which will be coming into contact with the bottom of the engine block, specially along the front side (top part in the pic). There was also quite a lot of 'gunky' residue left along here which I'm guessing is some kind of sealing compound to assist the gasket in making a good seal. What is it? Something like this?

[Peter_C]

If it were mine, I would carefully clean the flanges removing as little metal as possible, then seal it up with Loctite 518 applied very sparingly to the metal parts or the fiber gasket. Usually it is easier to apply to the metal, with less risk of damaging the gasket.
LOCTITE 518 - Gasketing product - Henkel

[Dan Gurney]

Sorry to resurrect this old dead horse, but (with all due respect to Peter_C) I have read some instructionals elsewhere which make no mention of jointing compound? Any comments?

[beamishken]

Most gaskets are intended to be used dry & some manuals will specifically say don't use sealant however they assume everything is as new but in the real world you sometimes need to use something extra to compensate for a little corrosion or pitting of the surfaces
I'd probably use a thin smear of a a good quality silicone gasket on either side of the base gasket or maybe as Peter suggests an anerobic type sealant
Wouldn't do it on a head gasket but on your application I'd probably use something extra just to help get a good seal & it also helps prevent further corrosion on the faces

[RIB-Teccie]

I hadn't seen this thread before. Hopefully this may cause a less painful experience for the next person who wants to dissect an old Yammy.

1) I've had the same pain of drilling out and helicoiling. Ideally when you buy an old yam remove and grease as many of the major bolts that will come out and replace to the correct torque. I wouldn't do cylinder head or exhaust covers. If one breaks you've just let yourself in for hell!

2) If it's too late for that and they don't look like they will move, leave them until you have to do something.

3) I had to change a friends mounts once and the bolts were solid. I let him know it would likely go to a drill and helicoil job and right before my eyes he performed magic. He used an air impact ratchet which broke the salt and they just spun out, the threads were like new. I use a battery impact but it's not as good. It really does work. Some still break but not all.

3) The worst is ever seen was a 90 yam which had to have the exhaust guide cut in two. Another way with powerhead bolts is to drill directly into and through them just below the block. The exhaust guide will look a pig but the head will come off, but I digress.

4) The aluminium parts of the yamaha shock mounts must be sealed with sealant to remove any slop between them and the mount housings. This also cuts down on corrosion. I don't recall it being in the manual but it was on the old wall hung lubricant & sealant guides. You get less trouble from the mounts if you do.

5) Grease every major bolt as you assemble. Waterproof marine grease is fine. Never grease a flywheel though or the nut. These nuts should have loctite applied.

6) The old yamaha base gaskets could be lightly greased. It's not "right" but I've never seen a failure and they just peeled off and left the alloy in good condition. No scraping!

7) Polish pitted alloy surfaces out with a scotch cloth disk on an air grinder. They come up like new without removing metal. My boss thought I'd taken them to a machine shop.

8) The newer yam gaskets are orange and come with sealant applied. I would pop some orange crank sealant into major pitting and apply gasket without sealant.

[Dan Gurney]

Originally Posted by RIB-Teccie

4) The aluminium parts of the yamaha shock mounts must be sealed with sealant to remove any slop between them and the mount housings. This also cuts down on corrosion. I don't recall it being in the manual but it was on the old wall hung lubricant & sealant guides.

What sort of sealant would you use for this?

The pitting on the leading edge is too much to grind out but I'll try the polishing thing to get a good seal on the bits that are there and then use liquid gasket on the pitted parts.

I'm into this thing for about 500 quid now including the machining! But I'd like to sell the boat as a complete package if I can so that someone gets some use out of her.

[RIB-Teccie]

It was the original grey crank sealant that Yamaha used back in the day. A standard orange crank sealant is fine.

[RIB-Teccie]

I can't remember what rib you have. Would it fit in a 20ft Container on its trailer?

[Dan Gurney]

It might do... Attaque (Ocean Pro) 5.3

I've got Dad coming down this weekend from the Auld Country and we're going to have a pop at it together. I kind of feel that having got it apart and sorted the threads etc, I'm over the worst of it. This may be ill founded confidence though

[RIB-Teccie]

If you got it apart and you take your time, it will go back together.

[RIB-Teccie]

Remember I'm only in Leeds if you are stuck

[Dan Gurney]

All done. Purring like a kitten. Sounds better than she did before we took her apart.

[mick]

Nice one Dan its a good sense of achievement when you do it yourself

[Dan Gurney]

You got that right! Be gutted to sell her but can't justify 2 ribs. Got to give her a good clean and I'll get her on the sales page.