Putting engine back into frame

Im rebuilding a 77 kz650 that was kindly donated to me by a friend who is leaving the country. The engine is currently on the bench. The case is back together, and the cylinders are on the case. I was wondering, what is the best stage to put the motor back into the bike?
Should I put the head or valve cover back on while it is on the bench?
Where is the balance between loosing clearance and ease of installation, vs. ease of working on the engine on the bench?
Any ideas and experience would greatly be appreciated.

Thanks in advance for the help.

MJ

I put the motor back in when it's just the cases then put the barrels and head on while it's in the frame. I've heard of guys putting the motor together then laying it on it's side and lowering the frame over the motor. I think it's no big deal putting the top end on in the frame.

Mark

I put the frame over the engine. Just the frame, no suspension.

I simply place a full engine into the frame. It's all aluminum basically so not heavy. :laugh: Well yes it is heavy. The way I do it is get some cinder blocks or the like and a piece of wood large enough for the engine. Have the motorcycle frame upright where you want it, put your blocks next to the frame to build a table basically the same height as what the engine is going to be in the frame. Tape rags ect, around the frame to protect it. Lift the engine onto your table. Take a rest. When you feel strong again, gain your energy up grab the engine and move it the 12" or whatever into the frame and you're all done. That wasn't so bad. Well maybe, but it works for me. I'm not laying over my motorcycles no matter how much easier it may be.

Switching out the motor completely assembled can be done... There is enough clearance to do it this way. My neighbor, my son, and I just lifted the old one out, and placed the new one in the frame. 2 guys on one side of the bike supporting 75% of the weight, and one guy guiding the engine into the rear mount position. We used an old skate board to scoot the engines around the garage.
Once placed in the frame. use a crowbar under the block to shift the engine into position for the motor mounts.

RonKZ650 wrote:

I simply place a full engine into the frame. It's all aluminum basically so not heavy. :laugh: Well yes it is heavy.

What are talking about, maybe 250 pounds for a 750 ballpark?

I call everyone who has posted here to come over and buy a lot of beer.

bountyhunter wrote: What are talking about, maybe 250 pounds for a 750 ballpark?[/quote]

A lot less than that, a fully assembled dry KZ650 engine weighs in at just around 145 lbs.

However, the main issue is not the weight of the engine but the risk of chipping the possibly freshly repainted frame and maybe busting your back - 145 lbs is not a lot if you're benchpressing at the gym, but lifting 145 lbs hunched over like Quasimodo trying to make it fit in and doing your best not to tip the bike over is a different story. I have tried several ways and I much prefer laying the engine on it's side and putting the frame over the engine, mount fork, swingarm and wheels and standing thewhole thing up. Last time I did it this way was this spring, took me less than 10 minutes and I didn't even sweat.