advice on my 400 project...

[Mateo]

Hi everyone.
In my spare time I've been tearing apart my motor to do a rebuild.
It's a 1978 gs400.
I'm excited about doing the project and I don't want to take the lazy way out but I also don't want to spend lots of money and not have the project work out...
I've found LOTS of problems and I'm not even finished tearing down the motor yet... In my inexpert opinion the head is toast. You can see that the PO tried to keep the bike going the cheap way and the bike suffered...
Then the cylinders are a little damaged... it needs new pistons... the cam shafts are damaged... There's a small crack in the oil pan...
SOOOO... the question is is it worth fixing? or should I just buy a 450 motor? I had hoped to use this motor and have an old school kick start only system but that seems like a lot of problems...
What do you guys think?

 

[Guest]

If you're patient and take your time, those parts don't end up being too expensive, and you may be able to get another head off eBay for a good price if you can snag it.

If you're in the US, then try Boulevard Suzuki for parts, prices are great and you can use their online fiche to get an idea of what you will need to fork out for everything.

One thing is if you use after market gaskets and O rings due to cost/availability, make sure you get OEM ones for everything in the bottom end like base gasket, cylinder O rings etc. Only use after market for things like valve cover and case covers where they're easy to replace.

I ended up with an after market head gasket and I'm just crossing my fingers it will be ok.

If you get another 450 motor, how do you know it won't be in the same condition internally?

 

[Sprockets]

Could you post some pictures of the damage? That way we could give some more advice, but you'd be surprised at what can be saved

-Gavin

 

[GearHead]

These are tough little motors and can take quite a bit of abuse. You can use gs 750 pistons in the 400. The bore is the same on both engines. Watch ebay. I've found allot of gs400 engine parts there. If the damage on the cylinders isn't to deep you might be able to get by with a cylinder hone and a new set of rings. Call a few welding shops and see what they would charge to weld up that crack in the pan. It shouldn't be too expensive.
You can probably save the motor. Take your time. the parts are out there and when your done, you'll know exactly what shape your motor is in and you'll learn allot doing the rebuild yourself.

 

[SVSooke]

The bottom end of your 400 is not the same as the 450.When they changed to plain bearings the mounting points changed as well.Just enough to not make it a bolt in option.

 

[Calliway]

personally I would look for another motor that is in running and good shape.

 

[Guest]

Gs400

Gs400

This may not be the right place to post, but, I have a '78 GS400C that is 90% complete. It is in slightly rough condition and would probably be best as a parts bike. Anyway, I am offering it for FREE to anyone who can come and get it from Alexandria,La. I don't plan on fixing it as I need a little bigger bike anyway. I do have a pair of first oversize pistons and rings for it too.

 

[Englishman]

This may not be the right place to post, but, I have a '78 GS400C that is 90% complete. It is in slightly rough condition and would probably be best as a parts bike. Anyway, I am offering it for FREE to anyone who can come and get it from Alexandria,La. I don't plan on fixing it as I need a little bigger bike anyway. I do have a pair of first oversize pistons and rings for it too.

Mr Bond
Sent PM and email. I would be interested in your 400C.

Thanks
Mark