Because of the problem with 2nd gear, my engine will have to be stripped down and rebuilt. The head, clutch, generator, sump and bottom crank case have to be removed to get at the gears. I've never stripped an engine before so I'm not too sure about it. Do I...

Buy / make the special tools and do it myself for just the cost of parts, gaskets and tools

Pay an ex-Yamaha mechanic, recomended by the main dealer, who runs his own garage "a couple of hundred quid" plus the cost of parts to do it for me.


Whilst I'm at it, is it worth replacing the piston rings and crank shells or as the engine was running fine, should I leave it alone?

as you said you never stripped an engine before, i would take it to a yamaha mechanic as you said, 200 quid plus parts is alot cheaper than a whole engine,
bike engines are bit more fiddly as the gearbox is part of then engine,
but then again you will never learn if you dont try yourself. so bit of a hard one

I wouldn't like to strip a bike engine as my first attempt. As said, they are a little bit more complicated than a standard car engine. Is there anyone near you who could give you a hand? Or see if the mechanic is free one weekend to help you, for the price of a few beers.
Also, if you do decide to do it yourself, get a large flat surface, not metal or wooden topped to lay things out on. Another good thing is to make sure you lie everything out from left to right in the order it cam apart/off the engine. Also, buy lots and lots of kitchen roll. I've been through a dozen rolls or more on an old A series before. Sandwich bags, the kind you can write on, are good for keeping things in groups.

[Edited on 18/9/06 by DIY Si]

Hi Colin you dont have to remove the head and the only specal tool you will need is a genni puller and thats just a big bolt
honest the job is easy i did one recently where the guy rode his bike here i removed engine replaced gearbox and refitted it and he rode away in 7 hours

easy job ring me if you need and ill talk you through it

cheers malc

well there you have it, straight from the horses mouth. think he done a few before.
goodluck, like i said you will never learn if you dont give it a bash.

Clutch nut can be a s*d to remove (unless you have an air impact wrench). Would leave the top end and piston rings alone if they aren't causing a problem (rings are easy to break and expensive), if it ain't broke dont fix it!

Like Malc says, do it yourself. It may seem a bit daunting at first but it really isn't too difficult. You just need to be methodical in your work.

Phil

give it a go. I did mine again!!!! the only bugger is getting the generator off. you need a big bolt to wind in to pull it off. the first engine i did i couldnt get the generator off with whatever i tried. big bolt, heat, hammer, air gun etc.... i had to grind the b@st@rd off in the end. a new generator is £200.00 from yamaha

AS already stated you do not have to take the head off. You should be able to do the full job in a weekend

[Edited on 18/9/06 by skydivepaul]

Haynes says that you need to remove the head, the clutch and the generator to get the crank cases apart. Is this not true? Aside from the sump and the 30 or so bolts that hold the crank cases together, what needs to come off to get the bottom crank case off?

If you aren't confident, why don't you get the mechanic to do it but ask if you could help. He might knock a few quid off and you learn how to do without the worry. Treat it as a £200 lesson.

quote:

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Originally posted by smart51
Haynes says that you need to remove the head, the clutch and the generator to get the crank cases apart. Is this not true? Aside from the sump and the 30 or so bolts that hold the crank cases together, what needs to come off to get the bottom crank case off?

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thanks for that Paul

One bit of advice...

When resealing the crancases, use the pukka yamaha sealant...

If not you run the risk of terminally blocking an oilway...

what about the gasket for the sump, ok to use a standard liquid sealant, as recommend by Honda dealer?

There are a few special tools needed for the job. A generator cover holding tool (the nut is torqued up to 95Nm so a strap probably won't do it) An alternator puller (is this just an M14 fine bolt as I'd read somewhere?) and a clutch holder so that the clutch nut can be undone.

Does anyone have one that I can borrow or know where I can get them cheap? For the cost of the proper tools, I might as well pay someone to do the job.

I say some pictures of an engine strip down on a swedish site (so I couldn't read the text). You don't have to remove the clutch unless you want to remove the main shaft. The offending output shaft and the bottom crank case will come off without. I don't know if you have to remove the main shaft to get the selector fork out to look at the selector drum though.

I've had the selector shaft off just now and it all looks to be in good condition so it must be something internal. I guess I'll start stripping the engine out then.

I didnt use any holding tools when stripping mine down because:

1) I didnt have any
2) the one i did have didnt hold it enough.

I used a 12V DC impact wrench, the sort you can carry around to remove your wheel nuts. Clutch bolt and generator holding bolt came off p1ss easy with this.

I think they cost around £20.00 and they are bloody handy

cheers

Paul