650 Restoration

[Hosk Engineering]

I am rebuilding a Yamaha 650 twin. This was a family bike that has been stored for at least 25 years. I am planning to track the project through the site, pick up some info on the way, and hopefully help others out who have projects of their own. It will probably be a very slow process with periods of down time but it is a good motivator to get er' done.

 

[Hosk Engineering]

History on the bike: It was dumped and parked from then on. There wasnt much damage to it. In fact it looks fine. I was told when it was dumped it would still start they just had trouble getting it into gear. When I first got it I ran through the gears and they worked with out issue.

 

[Hosk Engineering]

I am using a step by step guide I found online for getting an old bike that has been sitting back running. The first step was the fuel system. It still had gas in it from when it was parked. I pulled the tank and drained out the fuel. Not sure if I got it all out so if anyone has any ideas on the best way to drain it would be appreciated. Not sure on how the reserve tank works (I had the same bike as kid and it always baffeled me then as well) so that stumps me some.

 

[Hosk Engineering]

The next thing I did was pull the carbs and the air cleaner. I cleaned out the air cleaner but Im pretty sure Im just going to replace it. I also cleaned out the carbs and the bowls of fuel. The big debate here is weather or not to rebuild them or just clean them out and hope for the best. If it was running when they parked it Im guessing it is still in good shape. I pulled the battery and the battery box. Lots of rust around there as expected. Im planning to wire brush it all and repaint.

Air Cleaner

Carburetor

Battery Box

 

[Hosk Engineering]

Got out and took a bunch of shots of the parts that are disasembled to get ready for the next step but a little unsure on how to proceed. I was originally just planning on trying to get it started but I think I want to go a little further with it. I checked out the front brake master cylinder and the brake fluid had turned into almost a powder substance. So I am sure I will need to tear that down all the way, rebuild the carb, replace any gaskets in the system, and possibly rebuild the caliper (of course replace the pads). Not sure what you do with the rotors on these. Do you turn them, just replace them, or clean em up and go from there.

Front Rotor

 

[weekendrider]

Welcome to the site Hosk.
The cheapest way I've found to clean out old gas varnish is rubbing alcohol.
Followed by whiter vinegar to remove the rust.
The carbs will need to have the jets removed, the passages cleaned(carb cleaner in a can and compressed air). A good cleaning usually does it.

As you are looking through the posts you will notice alot of the signatures have a run down on the posters bike. It helps others when they answer your questions if they know what ya got. Pictures are always welcome.

 

[Hosk Engineering]

Another question now is do I pull the engine or work around it. Im sure I will need to pull the rims to service the tires and wheel cylinders which means the chain, which also should be serviced, so with all that would it be best to just pull the engine to give the frame a good scubbing and quick paint job. Or should I leave it on the frame and work around it. I want to do a good job on the bike but I also dont want this to be a marathon job that puts me years into the project before its done. Question should probably be, how dificult is pulling the engine and will it make the other stuff easier to do.

 

[Hosk Engineering]

Welcome to the site Hosk.
The cheapest way I've found to clean out old gas varnish is rubbing alcohol.
Followed by whiter vinegar to remove the rust.
The carbs will need to have the jets removed, the passages cleaned(carb cleaner in a can and compressed air). A good cleaning usually does it.

As you are looking through the posts you will notice alot of the signatures have a run down on the posters bike. It helps others when they answer your questions if they know what ya got. Pictures are always welcome.

Thanks a lot on that for the cleaning methods. On the picuture side I plan on posting pics just got started so I will update as I go.

 

[retiredgentleman]

Here's a link from the "Tech" section.
http://www.xs650.com/forum/showthread.php?t=37&page=4

Yes, you can turn the brake discs, if you have a drill press.

Removal of the engine involves some work and time for sure. It depends on the condition of the engine internals,as to the need to remove and open the top end.

What is the compression of the engine? Are you finding debris in the oil when you drain it? Does the engine smoke? Are the spark plugs blackened very quickly? These things will indicate its time to re-build the top end.

 

[Hosk Engineering]

Like the idea on the brake rotors. I have a drill press so it should work really well. Haven't seen it run so no idea on the engine smoking. Haven’t gotten into the fluids either but it’s a good reminder to check for the debris. The plugs were old but they didn’t look burnt. I think the best idea is to leave it on and get it running then I will learn pretty quickly if it needs to be torn down.

 

[Hosk Engineering]

Here's a link from the "Tech" section.
http://www.xs650.com/forum/showthread.php?t=37&page=4

Yes, you can turn the brake discs, if you have a drill press.

Removal of the engine involves some work and time for sure. It depends on the condition of the engine internals,as to the need to remove and open the top end.

What is the compression of the engine? Are you finding debris in the oil when you drain it? Does the engine smoke? Are the spark plugs blackened very quickly? These things will indicate its time to re-build the top end.

What I think I've decided to do is get all the rust off and touch up the frame before I drain the oil. So I don't know how the oil looks yet. When I do I was advised to run the oil through a coffee filter to look for particles. Things I was told to look for in the oil is the smell of gas to see if the carbs have been leaking. Look for black pieces of plastic (cam chain guide). Large bits may be 5th main gear or 3rd pinion gear dogs. Crank bearing cage pieces I'm told have been found along with broken clutch primary springs .

I also need to get a compression gauge. To check this do I just need to hook it up and kick the engine over?

I'll probably do this after I've changed to oil to make sure everything is good in there.

Front Rotor

Engine

 

[retiredgentleman]

What I think I've decided to do is get all the rust off and touch up the frame before I drain the oil. So I don't know how that's looking. I was advised to run the oil through a coffee filter to look for particles. Things I was told to look for in the oil is the smell of gas to see if the carbs have been leaking. Look for black pieces of plastic (cam chain guide). Large bits may be 5th main gear or 3rd pinion gear dogs, crank bearing cage pieces I'm told have been found and broken clutch primary springs.

I also need to get a compression gauge. To check this do I just need to hook it up and kick the engine over?

I'll probably do this after I've changed to oil to make sure everything is good in there.

Front Rotor

Engine

Yes, that brake disc will clean up just like new. The wheel rim needs some time spent on cleaning/polishing it as well. With some time and effort the engine can be made to look much better.

 

[Downeaster]

It's unlikely you will get a useful compression reading just kicking the bike over.

If the engine is free, hook a pair of jumper cables from a car-sized battery to it and spin it over with the starter motor. Be sure to hold the throttle open while cranking.

 

[5twins]

You may also not get the best reading on a cold engine. They usually read better and higher once hot. I usually use the kicker for my compression testing and it's always worked fine. That way I can do it with the key off. With the key on, if you forget to ground the plug that's out to the engine, you run the risk of damaging the ignition (especially an electronic one) or coil.

 

[xjwmx]

If you meant you were going to drill the rotors, I would wait to do that, actually I wouldn't do it. It's the kind of thing you do if you have time on your hands and you have plenty of things to do first!

First get it running and check that you have a working suspension and no oil leaks from the motor. You will probably want to do the bronze bushing mod to the swing arm. Do it carefully and thoughtfully. You can leave the neck bearings alone except for a good greasing if they work. I have the original ball type bearing setup. Make sure your charging system works. Re-do the brakes. Any paint on the frame should be fuel proof, since it will eventually see some gas, one way or another. Good tires is another must. I got tires by mail order and a local shop put them on the rims for $20 ea. (in Austin. I actually miss that place! Up here money is existence, as in how will you get gouged next...

 

[Hosk Engineering]

It's unlikely you will get a useful compression reading just kicking the bike over.

If the engine is free, hook a pair of jumper cables from a car-sized battery to it and spin it over with the starter motor. Be sure to hold the throttle open while cranking.

I've done that with my riding lawn mower before and it worked well. I have seen others go to far and burn things out but that is a good way to get an accurate reading.

 

[Hosk Engineering]

You may also not get the best reading on a cold engine. They usually read better and higher once hot. I usually use the kicker for my compression testing and it's always worked fine. That way I can do it with the key off. With the key on, if you forget to ground the plug that's out to the engine, you run the risk of damaging the ignition (especially an electronic one) or coil.

Sounds like a good way to get a quick reading just to see if it is in real need of a tear down. Once its running I should be able to get a more accurate reading and then decide if a full rebuild is in the future. It has pretty low miles so unless something happened I wasnt told about I feel pretty good it should be OK.

 

[Hosk Engineering]

If you meant you were going to drill the rotors, I would wait to do that, actually I wouldn't do it. It's the kind of thing you do if you have time on your hands and you have plenty of things to do first!

First get it running and check that you have a working suspension and no oil leaks from the motor. You will probably want to do the bronze bushing mod to the swing arm. Do it carefully and thoughtfully. You can leave the neck bearings alone except for a good greasing if they work. I have the original ball type bearing setup. Make sure your charging system works. Re-do the brakes. Any paint on the frame should be fuel proof, since it will eventually see some gas, one way or another. Good tires is another must. I got tires by mail order and a local shop put them on the rims for $20 ea. (in Austin. I actually miss that place! Up here money is existence, as in how will you get gouged next...

Not going to drill the rotors, like you said much more to do. "retiredgentleman" posted a method of turning the rotors to clean them up when change out the pads using a drill press.

Thanks for info on the steering. I know I will have to go through all that as well.

I am wonding if I should use engine paint on the frame, that was a good point about the fuel proof.

I also appreciate the tire input. I was debating about the tires because of cost but it really is a must do as long as this has been sitting. The charging system is good also. Batteries are expensive.

 

[xjwmx]

^Even turning the rotors is a sort of an extra. They'll clean themselves up after you re-do the brakes. Mine even has deep ridges but I can still lock up the front wheel.

The place I get tires from is I think motorcyclesuperstore.com. I remember they ship out of Louisville, anyway. Shipping is free, which would otherwise kill you. And the prices themselves are the best around. Bridgestone Spitfires or Kenda Challengers are good choices. They're similar. Spitfire tread might last a little longer and Challenger might do a little better in adverse conditions.

Engine paint is heat proof but not sure if it's fuel proof.

Got a good, cheap battery from Napa.

 

[5twins]

I noticed in your motor pic that the head gasket is leaking. That's very common on these bikes. See those rubber washers under the two big acorn nuts on top? That's the usual cause. They let those nuts and the corresponding two on the other side come loose all the time. Most of us replace them with copper or brass washers, soft enough to seal but hard enough to hold the torque. Also, use about 30 ft/lbs instead of the factory spec of around 26.