Jump to content
Yamaha Tenere 700 Forum
  • 0

OEM engine guard M12 bolt hole stripped thread...


Treps

Question

I tried to fix the OEM engine guards. One side was fine. On the RHS the main bolt (M12) that goes into the engine casing actually stripped the thread in the hole. Recommended torque is 75Nm. I put 50Nm as I thought 75 was a lot. I have calibrated the torque wrench before and after! 

I tried a helicoil but that is not working. The thread is just too deep inside the casing hole so I cannot get the helicoil all the way in. 

Has anyone had a similar issue of the stripped thread in the casing? What solution did you end up with? Other solutions? 

Where can I source a new OEM M12 bolt? 

Is warranty out of the question...?

Many thanks for your help. 

Link to comment
Share on other sites

16 answers to this question

Recommended Posts

  • 0

You might try to run a tap into the hole to see if that cleans up the thread route along with a new bolt of course.  And if it does, don't over tighten the new bolt as it will have less thread to grip onto.  Maybe a wee bit of loctite will aid in keeping it moored.

I would clean up the threads anyway as that may make the helicoil installation easier.  Let us know how things work out.

  • Like 1
Link to comment
Share on other sites

  • 0

You can always try  drilling/tapping it one size up or even go to standard size that’s just a touch larger. 

  • Like 2
Link to comment
Share on other sites

  • 0

Can you post a photo of the hole/thread you are trying to repair. I might be able to assist you. IIRC (sorry, I'm working out of town and don't have access to my bike - only pics of it) the OEM engine guards don't thread directly into the engine casing but to motor mount locations. I've pulled the manual and it looks like the forward engine mount/forward OEM engine guard mount threads into the head. If this is the one you are referring to, this could be tricky.

  • Like 1

I think I have Yamaha disease...

Link to comment
Share on other sites

  • 0
On 10/2/2021 at 3:06 PM, Canzvt said:

Can you post a photo of the hole/thread you are trying to repair. I might be able to assist you. IIRC (sorry, I'm working out of town and don't have access to my bike - only pics of it) the OEM engine guards don't thread directly into the engine casing but to motor mount locations. I've pulled the manual and it looks like the forward engine mount/forward OEM engine guard mount threads into the head. If this is the one you are referring to, this could be tricky.

Hi, pics below. Sadly I think that is the one...

Any help appreciated. 

 

IMG_4689.jpg

IMG_4686.jpg

  • Sad 1
Link to comment
Share on other sites

  • 0

Hmm. I was afraid of this. Did you manage to tap the full depth of the hole with the Helicoil tap? If so, can you figure out some method of screwing in the Helicoil insert further (looks like you are almost there...) for full engagement? Considering the location and IMPORTANCE of this mount, the Helicoil is your best option.

 

After looking in the manual and the parts list, there appears to be a threaded bushing between the frame and cylinder head that LOOKS LIKE what you are trying to repair. I have no idea if this is correct, or if it is replaceable, but elsewhere on this site there was a guy who blew up his T7 engine and replaced it with an MT07 engine. Perhaps you could request him to take a look at the side mount and take a picture of this bushing, This may help you out a bunch. The downside, is that, it looks like the engine must be dropped a bit (meaning all mounting bolts are removed) in order to get this bushing out.

 

Sorry, but that's all I got...

Engine Adjuster Bush.JPG

  • Like 1
  • Thanks 1

I think I have Yamaha disease...

Link to comment
Share on other sites

  • 0

Upon looking at this again, I think you still have the same problem. It looks like the frame is threaded for this #14, and the head is threaded M12. #14 is threaded in/out in order to obtain frame/engine alignment, then the M12 is threaded into the head.

 

Again, please check with the guy who replaced his engine. I'm sure he will have some wisdom.

  • Like 2

I think I have Yamaha disease...

Link to comment
Share on other sites

  • 0

Just happened to me too. Thread holes in the engine at that spot also sheered from my outback motortek crash bars. Bolt sheered them. Did you ever find a solution?

  • Like 1
Link to comment
Share on other sites

  • 0
  • Moderators
On 3/4/2022 at 11:51 AM, loneranger700 said:

Just happened to me too. Thread holes in the engine at that spot also sheered from my outback motortek crash bars. Bolt sheered them. Did you ever find a solution?

Here's a continuation of this problem on another thread that might help. Good luck!

  • Like 1

 

"Men do not quit playing because they grow old, they grow old because they quit playing" Oliver Wendell Holmes - Mods - HDB handguards, Camel-ADV Gut guard, 1 finger clutch, The Fix pedal & Rally pipe, RR side/tail rack, RR 90nm spring & Headlight guard, Rally seat, OEM heated grips- stablemate Beta 520RS

Link to comment
Share on other sites

  • 0

For critical repairs, I prefer using a Time-Sert rather than a helicoil.  They require a kit of proprietary tools and you need an extra 0.2" of depth in blind holes.  I'm not sure that is available in this case. 

 

Did you use a bottoming tap for the helicoil?  If one was not necessary, you probably have enough room to use a Time-Sert.

Link to comment
Share on other sites

  • 0

Well, the helicoil seems to be holding. However, after a particularly rough offroad ride, the bolt came loose.  I must have ridden a good two hours with it totally loose. And there is no sign of anything having come apart, deformed or fallen off! So the question is, if the hex 13 ‘insert bolt’ tightens the engine to the frame, what is the purpose of the M12 bolt? Surely not just to fix the OEM engine guard..?  

Link to comment
Share on other sites

  • 0

This thread deserves a bump for all those thinking of installing bars.  There is no  definitive explanation above as to why the engine threads were stripped but we could look at some possibilities.  Perhaps there was  misalignment between the long threaded hole into the engine and the shallow threaded hole on the frame?  This could have caused extra stresses.  I noticed that occurring in my own installation and jacked the engine slightly so as the bold went in with finger pressures.  Also the torque wrench used to tighten the bold could have been out of calibration.  OP says they calibrated it before and after but how was this done? 

 

I did the oem bars but didn't have the issue.  I used a torque wrench but not a cheap shop one, a Warren & Brown one that was worth $700 and that was nearly 2 decades ago.    I have a smaller Kinchrome one and another T&E Technologies one for rough stuff but for critical work on bikes, especially around the Engine, it's the W&B every time.  I also have a huge cheap one that I use for Axel nuts and the like.  I don't know how accurate it is but it's better than nothing.

  • Like 1
Link to comment
Share on other sites

  • 0
1 hour ago, winddown said:

This thread deserves a bump for all those thinking of installing bars.  There is no  definitive explanation above as to why the engine threads were stripped but we could look at some possibilities.  Perhaps there was  misalignment between the long threaded hole into the engine and the shallow threaded hole on the frame?  This could have caused extra stresses.  I noticed that occurring in my own installation and jacked the engine slightly so as the bold went in with finger pressures.  Also the torque wrench used to tighten the bold could have been out of calibration.  OP says they calibrated it before and after but how was this done? 

 

I did the oem bars but didn't have the issue.  I used a torque wrench but not a cheap shop one, a Warren & Brown one that was worth $700 and that was nearly 2 decades ago.    I have a smaller Kinchrome one and another T&E Technologies one for rough stuff but for critical work on bikes, especially around the Engine, it's the W&B every time.  I also have a huge cheap one that I use for Axel nuts and the like.  I don't know how accurate it is but it's better than nothing.

 

There are a lot of ways to strip a bolt with or without a torque wrench but only two possible causes -  Operator error or a defect.  Starting bolts by hand is a great way to avoid cross threading. Being familiar with what the torque numbers are and actually mean combined with a decent torque wrench avoids the second most common reason for striped bolts. 

 

As for the threaded bushing that's mentioned - I haven't had any reason to have my engine mounts off but I'm quite certain the threaded bushing mentioned acts as an adjustable spacer between the frame and engine. It doesn't bolt the engine to the frame. It allows for small variations between the frame and engine but more importantly allows the engine to be installed and removed easier. Once the engine is in place within the frame the threaded bushing is run in to contact the engine to eliminate any space between the frame and engine which in turn prevents the frame from being tweaked/stressed when the engine bolts are tightened. 

 

 

Link to comment
Share on other sites

  • 0
10 hours ago, Windblown said:

 

 I'm quite certain the threaded bushing mentioned acts as an adjustable spacer between the frame and engine. It doesn't bolt the engine to the frame. It allows for small variations between the frame and engine but more importantly allows the engine to be installed and removed easier. Once the engine is in place within the frame the threaded bushing is run in to contact the engine to eliminate any space between the frame and engine which in turn prevents the frame from being tweaked/stressed when the engine bolts are tightened. 

 

 

 

Yes that's quite correct, I probably confused the issue by mentioning that the frame hole has a thread in it, what I was referring to was that the central hole in that frame adjuster can be misaligned with the bolt hole in the engine.  Quite easily!  If that is the case and you simply force the bolt into the engine block it may go in cross threaded or with undue force in one direction.  Once a bolt starts to strip out a thread at the mouth of the bolthole it will continue to hey.  Perhaps this is what happened?  I couldn't imagine 50Nm stripping that bolt, it had a lot of thread on it. 

  • Like 1
Link to comment
Share on other sites

  • 0

It really bugs me that so many bikes have crash bars, or skid plates that mount to the engine.  So many things can go wrong. 

 

Years ago a buddy of mine had minor accident on his BMW GS. When he hit the ground, his engine mounted crash bar busted a hole in the engine case totaling the bike.  

Tenere 700 / Africa Twin / Goldwing / Super Tenere / WR250R / GS1000S / GT750 / H2 750

Link to comment
Share on other sites

  • 0

Yes, it's a worry.  I think the fact that they use the engine itself as part of the frame probably leads the designers to think this is ok.  Let's hope they know what they are doing and not just cutting corners to save money, like nearly every corporation on the planet does now. 

 

Yesterday I bought a new 2kVA Honda generator, I already had two gen sets sitting down in the garage but couldn't get either started.  Both mind you I had fitted little inline fuel filters to, always used fresh fuel, ran then up every month.  The bigger one, the stupid Aldi one, a 2kVA, I actually had running for 10 minutes then I stopped it to add fresh fuel.  It wouldn't restart.  It backfired twice though after about 50 pulls!  Never had that happen before...  Oh I have worked on small engines before too, I know the drill, check for vapor lock, fuel in the bowl, I checked the plug, took off the air filter and then looked at the carb figuring clogged jets perhaps?  Then I just said to hell with it, I've wasted enough of my life battling with these Chinese anchors.  In 20 minutes it was given to a neighbor and I was driving off to get a Honda. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Our Friends

Tenere across the USA

Tenere 700 Forum. We are just Tenere 700 owners and fans

Tenere700.net is not affiliated with Yamaha Motor Co and any opinions expressed on this website are solely those of ea individual author and do not represent Yamaha Motor Co or Tenere700.net .

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.