Engine mounts

[Normski xs]

Hi everyone I’ve just got my engine back in loosely and I’m wondering if there’s a sequence to doing up the engine mounts, sequence and torques would be great if anyone can help cheers

 

[Raymond]

My only tip - put the carbs on now before you do the engine bolts. With just the lower middle bolt loosely in, bit of rag to protect frame from exhaust studs, tilt the motor forward a bit, plenty access to fit the carbs.

I'm not aware of any particular sequence to the engine bolts and I don't suppose it's crucial like torquing a cylinder head but I expect someone will be along with the correct answer soon.

 

[eidemaddin]

Hi, these torques are from the XS1/2, but there shouldn't be any difference to the others. Overall, these are no sensitive values and the sequence of tightening is not important either. But it's important to put all the bolts in first before you start tightening them, otherwise the last ones might no longer fit, especially on the upper brackets!

Raymond recommends it exactly right: first insert the lower middle bolt only, then swing the motor forward and install the carbs before moving on to the rest of the bolts. This is the only situation in which you have this “luxury” of convenient carburettor installation

 

[NP2650]

Manual suggests re-installing in the reverse order.

 

[Normski xs]

My only tip - put the carbs on now before you do the engine bolts. With just the lower middle bolt loosely in, bit of rag to protect frame from exhaust studs, tilt the motor forward a bit, plenty access to fit the carbs.

I'm not aware of any particular sequence to the engine bolts and I don't suppose it's crucial like torquing a cylinder head but I expect someone will be along with the correct answer soon.

Cheers mate

 

[Normski xs]

Hi, these torques are from the XS1/2, but there shouldn't be any difference to the others. Overall, these are no sensitive values and the sequence of tightening is not important either. But it's important to put all the bolts in first before you start tightening them, otherwise the last ones might no longer fit, especially on the upper brackets!

Raymond recommends it exactly right: first insert the lower middle bolt only, then swing the motor forward and install the carbs before moving on to the rest of the bolts. This is the only situation in which you have this “luxury” of convenient carburettor installation

Cheers bud

View attachment 261534Manual suggests re-installing in the reverse order.

 

[Normski xs]

View attachment 261534Manual suggests re-installing in the reverse order.

Cheers buddy

 

[5twins]

Here's a chart I put together. Personally, I use the '77D values as they make the most sense to me. I don't know why Yamaha increased the value so much on the Special for that long lower bolt (#5), but I think it's too much. I might go a little more on it, like maybe 45 pounds, but I wouldn't chance 65 .....

And yes, some of the manuals do specify removing and then tightening after install in the order shown.

 

[Normski xs]

Brill, thanks mate

Here's a chart I put together. Personally, I use the '77D values as they make the most sense to me. I don't know why Yamaha increased the value so much on the Special for that long lower bolt (#5), but I think it's too much. I might go a little more on it, like maybe 45 pounds, but I wouldn't chance 65 .....

View attachment 261548

And yes, some of the manuals do specify removing and then tightening after install in the order shown.

 

[toglhot]

The holes in the mounts and frame are quite a bit bigger than the 10mm bolts. The longer the bolt the more movement of the engine. For that reason, I install the bottom bolt first but don't tighten it, then install the rear and front mounts, tightening the rear mounts first, the front mounts next, then the lower centre bolt. Top mounts - who cares, they are just hinges!
Measuring doesn't amount to more than a mm or two, but if you're fussy?

 

[Normski xs]

The holes in the mounts and frame are quite a bit bigger than the 10mm bolts. The longer the bolt the more movement of the engine. For that reason, I install the bottom bolt first but don't tighten it, then install the rear and front mounts, tightening the rear mounts first, the front mounts next, then the lower centre bolt. Top mounts - who cares, they are just hinges!
Measuring doesn't amount to more than a mm or two, but if you're fussy?

Cheers mate

 

[Normski xs]

The holes in the mounts and frame are quite a bit bigger than the 10mm bolts. The longer the bolt the more movement of the engine. For that reason, I install the bottom bolt first but don't tighten it, then install the rear and front mounts, tightening the rear mounts first, the front mounts next, then the lower centre bolt. Top mounts - who cares, they are just hinges!
Measuring doesn't amount to more than a mm or two, but if you're fussy?

Cheers mate