Will Longer Intake Manifold Bolts in Short Bolt Spots Cause Problems?

[Bob K.]

When I removed the intake manifolds on my '93, the two short bolts were on cylinder #1 in the outside spot and cylinder #3 in the outside spot. They've been like that since I bought the bike in 2001. I reinstalled them that way.

 

However, I just discovered that the short bolts are supposed to be on cylinder #2 in the outside spot and cylinder #3 in the outside spot. That means I've been running a long bolt in that cylinder #2 spot for 17 years. I've never noticed a problem.

 

https://www.venturerider.org/forum/showthread.php?79927-intake-carb-boot-bolts

 

 

What are the consequences of having a long bolt in a short bolt position?

[Prairiehammer]

 

What are the consequences of having a long bolt in a short bolt position?

 

The longer bolt will break through into the head nut recess, with the likelihood of an oil leak at the intake port.

 

Go here for an example and the fix:

 

http://www.bikersassociationofnorthdevon.co.uk/projects/Vmax-renovation.htm

 

Scroll down in his post to the identified problem.

Edited October 8, 2018 by Prairiehammer

[videoarizona]

A very enjoyable read about the VMax build.

Thank you, Kevin!

[Bob K.]

Interesting. The long bolt has been there since I purchased the bike--presumably installed incorrectly by the previous owner or his motorcycle shop--however, I've never noticed any problems or oil leaking into the #2 cylinder. No oil burning, no fouled plug, no buildup in the intake portion above the intake valve, no loss of oil.

 

Oil does leak out of the hole when the bolt is removed, but as I understand from other posts, this is normal, and that's why the bolt needs sealant on it during reinstallation. Is that correct?

 

I'll swap the bolts and see what happens.

 

Is there anything in particular I should keep an eye out for?

[Prairiehammer]

 

Is there anything in particular I should keep an eye out for?

 

Only thing I can think of is that the torque for the short bolt is about half that of the longer bolt. Don't strip it out!

 

Frankly, I'm not sure I would mess with it. The minor damage done by the incorrect long bolt will not be fixed by the substitution of the correct shorter bolt.

 

As an aside: the parts diagram is the reason for the (probably) many examples of the long bolt in the wrong location. Notice, even though the part number describes a 16 mm long bolt, the diagram clearly shows the longer (20mm) bolt in that location.

[Bob K.]

As an aside: the parts diagram is the reason for the (probably) many examples of the long bolt in the wrong location. Notice, even though the part number describes a 16 mm long bolt, the diagram clearly shows the longer (20mm) bolt in that location.

I noticed that, too! #7 is supposed to be the short bolt, but in the fiche, it's drawn as longer than the #6 bolt. Dang artists!

Edited October 9, 2018 by Bob K.