engine mounted in frame but lots of play in rear stud

[jjwithers]

I mounted my engine back into the frame last night and noticed a significant amount of space between the REAR stud spacers/engine/frame on both sides.
Is it safe to add some washers in that area to shim it? I could easily fit a washer or two on either side.
Otherwise when i torque the nuts, it will squeeze the frame.

The front engine stud is OK with the center stand spring mount spacers. The rear definitely caught my attention though.

Thanks.

-J

[Motorhead]

this is unusal and demands more closer look

look at your other bikes BMW

if the frame is maybe over 1/8"h space motor mount that maybe too much..... but ok home built to pull it in

[jjwithers]

I did check my other bikes and they had the same type of spacers on the rear stud. This is the same engine that came out of the frame (R75/5).
The space isn't that big... but like i said, a washer or two on either side of the engine would probably help. Or a larger spacer...?

[kutter]

My 1981 RS has two spacers on the front
engine bolt and two on the back.
One each side between the engine and
the frame. These measure 6mm each.

[Duane Ausherman]

A /5 should only have a single spacer on each motor mount bolt. and be tight. Many times these got perverted and tightened down, only to give a new set to the frame geometry. Who knows what you have now. That is why one should photograph every single part before removing it, label it and make notes as needed. Then it can go together with fewer errors and faster.

[jjwithers]

The spacers i have for the bike are the exact same thickness spacers i have on my other bikes. They are true and not damaged in any way. There seems to be just about enough room for a washer on either side before I tighten the bolts. I had the frame checked with the frame jig before i assembled the bike and everything is straight.
I guess my only solution at this point is to add washers. I don't want to put that kind of stress on the frame if it is un-natural or going to put stress on it unnecessarily ... however it could very well have been 'stressed' when I took the bike apart and i didn't notice it.

And Duane, i have many photos bags of labeled parts but some items, like these, seemed like a 'no brainer'.
But my brain sometimes isn't the sharpest tool in the shed...

[Major Softie]

But my brain sometimes isn't the sharpest tool in the shed...

But it is the only one that gets sharper with more use.

[Duane Ausherman]

How far the frame is spread, or pulled together won't change the result from using the frame jig. We saw many frames get a new set due to many reasons. Sometimes the person loses a spacer and doens't know it. Some of the accessories used that space and once removed they did't know to add back in a spacer.

The good news is that one should install everything correctly and then the nuts will pull it all together. Over time, the frame takes to proper set again. It wasn't uncommon to have to pry the frame tube out to get a spacer in place.

Far more important is the space just behind the battery where you have a non triangleulated section that holds the swing arm, depending upon model. Most like to equally space the swing arm, but that is wrong. One should be far more concerned about having the driveshaft centered in the swing arm tube. That area gets bent easily in a crash with any side stress. I think I mention this on my article on frames.

[jjwithers]

Thanks Duane. Your article on the driveshaft alignment helped. I hadn't considered the effect the frame would have on the driveshaft until now. Makes perfect sense. Right now my swingarm is aligned in the frame but the tranny isn't installed. Once i install it, i will test the alignment of the driveshaft.