Swap engines or almost everything else? Which would you do?

Bike 1: All parts good except engine - Broken primary chain guide and possible tranny problem. Never drove this bike, but it started easily and idled smooth.

Bike 2: All parts not as good as bike 1 except for engine. Engine has good compression. All cylinders hit between 120-125 with carbs off. Bought this as parts bike and never attempted to make it run.

Question? What's the path of least resitance at this point? Put engine from 2 into 1? Or, swap almost everything else from 1 to 2? The only likely exceptions would be wiring harness, frame, triple tree, swingarm and drive.

 

Re: Swap engines or almost everything else? Which would you

Not sure on a Maxim as I have not done it but I recently pulled the engine on my 550 Seca and it was no problem what so ever. Real straight forward to do, took about 1/2 hr or so....Chassis, wire harness, etc. is also layed out and friendly to work about but there is a lot of ground to cover going that way...One plus with swapping the engine is that it provides a chance to give everything a good clean up and inspection....mandatory process (IMO) with a bike that has a couple decades of unknown history...........

 

Re: Swap engines or almost everything else? Which would you

That's a hard one to call. If you're doing it by yourself, leave the engine and swap the small parts. If you can get a friend or 2, swap motors. You can clean up and paint the engine while it's out. Plus, it probably won't take as long.

 

do you have titles for both frames? is either road certified yet (plated, inspected, etc).

Depending on where you live replacing lost titles is a bitch to nearly impossible. some states are a simple fee.

Regardless of which frame you use, consider pulling out the motor and spray painting the frame (easier touch up) & clean/polish/paint engine , check for cracks and hidden rust and any other surprises. Be sure NOT to paint over ground points and under the handle bar switches (normally grounded to the handlebars w/o a ground wire).

 

I just went through the same exercise, my parts bike is now my project bike. Easy to get the engine out, but a heavy lift to do on your own, took two of us, a case of beer and a couple of hours. Now I have a bare frame to start a clean rebuild.

 

Re: Swap engines or almost everything else? Which would you

I've got titles to both, but neither is tagged or inspected.

 

Swap everything onto bike # 2. That way the engine matches the frame.

Perhaps less hassles later down the road.

 

I can't agree with Techlinetom...Put engine number 2 in bike number 1. I did this with my bike(s) as I couldn't be arsed to strip an engine to look for a transmission problem - and nor should you if you have a good spare motor.
It's a lot quicker to swap an engine than EVERYTHING ELSE on a bike.

 

I started this engine swap today. Came off the parts bike and onto the bench fairly easily.

I'm planning to check/adjust valve clearances and clean it up a bit. What else should I do to this engine while i've got it out?

 

Flip it over, split the cases and replace the primary chain guide now? Or ride it until one day it won't shift gears all of a sudden, like the other unit.

I know, it's a tough decision. My 650 Seca has 13K on it. Fix it now or wait until it fails?

 

EVERYTHING!

If it can fail, replace it now.


Might as well fix it now, and be worry free after the build.

 

+1

With the motor on the bench, and everything accessable. Do not try to cut corners, and cheap out.

Check the following know issues.
Starter clutch
Chain guides
Replace the 30 year old seals, and gaskets
Check all clearances
Fix anything questionable. stripped threads, broken bolts.

Ghost

 

Re: Swap engines or almost everything else? Which would you

Thanks to all for the input. I guess I'll dive in and do it right.

 

Be sure you have a manual. There are some very critical spots inside the motor that need a special type of sealant (Yamabond #4 or equivalent) and more importantly there are some VERY specific places to NOT put it. This particular detail is critical to bottom end oil pressure.

 

Having the Factory Book at a time like this will help guarantee you get in there and provide reassurance as you progress along the steps of dismantling the plant.

The Books steps are numbered.
There are illustrations with circled areas identifying what part is referred to in the text.

One thing that will make the job a success is this tip when its time to place the Cases together again.

Having several "Locating Dowels" that will guide the two cases together helps you guide the two sections together with precision.
1/4" Dowels fit the 6mm Holes and let you join the two sections togoether without smearing the sealant.
Short money.
http://store.cincinnatidowel.com/36_-Maple-Dowels/632

Before you apply the Sealant, ... insure that the surfaces are squeaky clean.

 

I don't know about your area......around here, as far as older bikes like ours are concerned--nobody cares about matching numbers. That's only an issue for newer bikes.

Dave

 

Re: Swap engines or almost everything else? Which would you

Thanks to all for the excellent advice.

I'm planning to tear my engine down and replace the seals, chain guide and check out the starter clutch. I've got a factory manual, digital camera ready to go and plenty of boxes, bins, trays, etc. to sort and store parts.

My Father-in-Law (ASE mechanic) will be coming into town for a couple of visits over the next 2 months. I hope to have everything dismantled when he makes his first visit and evaluate what needs to be done. Then have everything vatted and machine work done if needed. Hopefully we can reassemble everything when we comes back to town later.

Any other tips or anything I need to consider?