How To Re-torque the Engine Mount Bolts?

[FJRat]

If I was gonna retorque the engine mount bolt, how do I start?

The manual has the sequence for engine removal and re-installing. But if you engine is not going to be removed:

Do I losen all the bolts?

Do I losen them one at a time?

Does the engine have to be supported with a jack?

What would be the correct procedure for retorquing the engine mount bolts?

The reason why I ask is that there are theories around that claim retorquing the engine mount bolts gets rid of all vibrations on the handlebar.

 

[Fred W]

Yes, having the frame under "stress" by having improperly tightened the engine bolts can allow more engine vibration to be conducted through the frame to the bars and pegs.

Just loosen them all (order is inconsequential) then re-torque them in the prescribed correct sequence.

Essentially what you will be doing is drawing the engine to the left side of the frame first, then torquing the pinch bolts on the right side of the frame afterwards. That way you do not flex the frame by pulling on previously tightened pinch bolts.

I have toyed with the idea of doing this after first getting the engine fully heat soaked (like after an hour or two of riding) as some of the dimensions are likely to change slightly when everything is up to temp.

 

[NMRoadRunner]

Now this is gonna screw you up, but you're not supposed to "re-torque" bolts after they have be "torqued". You follow me? And by the way you "tension" them to a specific torque value. They won't tension the same the second time. Same reason you replace head bolts when you rebuild. Me? I would do the exact same thing you are planning on doing. Just sayin, thats all. Carry on.

 

[RadioHowie]

https://www.fjrforum.com/forum//index.php/topic/127669-buzzing-foot-pegs/?p=725958

Here's your 1-2-3-4, etc., for torque sequence, with pics.

 

[Fred W]

Now this is gonna screw you up, but you're not supposed to "re-torque" bolts after they have be "torqued". You follow me? And by the way you "tension" them to a specific torque value. They won't tension the same the second time. Same reason you replace head bolts when you rebuild. Me? I would do the exact same thing you are planning on doing. Just sayin, thats all. Carry on.

That is only true in those limited applications where the torque spec is high enough to stretch the bolts to yield, like with head bolts.

Most other applications have torque specs well below the stretch point of the fastener, so there is no problem loosening and re-torquing those fasteners.

The engine mounting bolts are not that highly torqued.

 

[xcsp]

So is anyone putting anti-seize compound on the engine bolt threads when removed for installing sliders or canyon cages?

 

[Fred W]

No. The FSM doesn't call for it, and I've never heard of anyone galling the threads on the engine mount bolts.

If you were to grease them (like with anti-seize) or use a thread-lock compound (like locktite) on them then the torque specs will be much too high and you risk damaging the threads.

 

[Enn]

https://www.fjrforum.com/forum//index.php/topic/127669-buzzing-foot-pegs/?p=725958
Here's your 1-2-3-4, etc., for torque sequence, with pics.

When I did the re-torquing I consulted the Yamaha Service Manual (pg 5-6, 5-7) and the tightening order was a bit different there. According to it you should start

1. The upper left side frame spar bolt, 35 ft.lb

2. Right lower side bolt above the foot peg, the torque is 32 ft.lb, not 35 as for others

3. Right engine mounting nut on the bolt which goes through the engine, torque is again 32

4. The lower left side frame spar bolt, 35 lb

5. Right side upper frame spar bolt, 35

6. Right side lower frame spar bolt, 35

7. All 4 pinch bolts, 17 lb

I am not sure if that makes a big difference though...

 

[xcsp]

No. The FSM doesn't call for it, and I've never heard of anyone galling the threads on the engine mount bolts.
If you were to grease them (like with anti-seize) or use a thread-lock compound (like locktite) on them then the torque specs will be much too high and you risk damaging the threads.

Thanks Fred!

 

[Donal]

No. The FSM doesn't call for it, and I've never heard of anyone galling the threads on the engine mount bolts.
If you were to grease them (like with anti-seize) or use a thread-lock compound (like locktite) on them then the torque specs will be much too high and you risk damaging the threads.

The other side to this particular coin is that IF the threads are not in 'as new' condition then most of the torque you apply to the bolt will be 'lost' in friction and the correct pre-load will not be applied to the bolt.

Remember, when the torque figures were calculated it was using 'typical' figures for as new bolts/threads..........

 

[HyperPete]

Thank you for this thread. I am heading out to do this right now.

 

[John d]

Thank you for this thread. I am heading out to do this right now.

Let us know if you end up with a discernible difference or not.

 

[HyperPete]

Thank you for this thread. I am heading out to do this right now.

Let us know if you end up with a discernible difference or not.

Well, I also added heavy bar-end weights, and will be replacing the spark plugs, and doing a throttle body synch. So there SHOULD be some difference! I'll find out if it ever stops raining around here.