Thread: Over tightened all the bolts????
09-13-2009, 06:13 PM #1
Over tightened all the bolts????
Ok...I was putting my 05 gp1300r back together this weekend (replaced pistons and replated one cylinder) and somehow I tightened all the bolt too tight. I was tightening foot pounds but reading N.m
So every bolt in the cylinders and exhaust is tightened about 10lbs too much.
cylinder head is tightened correctly.
Will this cause me any problems?????????
09-13-2009, 06:22 PM #2
over tightening can cause bolts to break. metals get soft when they are heated up and with 10+ lbs extra it's really straining the bolt. also you got to take in mind about the gaskets. if i were in your shoes i would retorque the bolts to spec. i've have a bolt break off in the muffler stay and it was a b!&ch to get out. not to mention all the vibration from the motor adds strain to the bolts.
09-13-2009, 06:33 PM #3
Can I just loosen them up or do I need to replace all the gaskets/ That would be a huge job.
09-13-2009, 06:35 PM #4
Now this is the Pro Engine builder in me talking...
I would scrap all the bolts and start over. Bolts can only be stretched so many times before they get weak. I will use a bolt over once and that is it. That is if is one that I know will take the re-use.
When you torque a bolt, what you are doing is actually stretching it to a predetermined point. This is why we use bolt stretch gauges instead of tq wrenches where I work.
So it is your call. Are new bolts and gaskets cheaper than the damage that may happen?
09-13-2009, 07:00 PM #5
I will put it this way. I have my torque wrench handy whenever I am working on my skis. Some bolts are more important than others. A bolt that gets set to 10 will be ok at 12 or 15 even. Some bolts are torque to yield (we don't have these) I am almost finished putting my 00 back together and I used the torque wrench wherever it was applicable > 10ft lbs. No one here is going to say don't worry about it b/c it would make them look like a bad tech themselves. However, having worked around dealerships and other repair facilities I can assure you the only thing the tech in the back room of your local dealership uses the torque wrench for is the head and maybe the exhaust. Most everything else is G&T (good and tight) I would NOT replace anything for 10ft lbs. Those exhaust and cylinder bolts are large enough to handle that variance.
09-13-2009, 08:03 PM #6
09-13-2009, 08:43 PM #7
I take pride in my work and I try to do it better than everyone else. I may not succeed, but I do try. More than can be said for most. This is the reason I am the highest paid employee my boss has ever had. I earn it.
09-14-2009, 08:30 AM #8
Awesome guys....thank you so much for the info.
I really appreciate it.
09-14-2009, 09:58 AM #9
- Join Date
- Jun 2008
- St Clair Shores, MI
Head bolts - do them right
cylinder bolts to crankcase - probably do them right
everything else - don't worry about it. I don't even use a torque wrench on most of that stuff, and half the cheap torque wrenches you buy are off a bit anyway. I wouldn't lose sleep over 10 ft-lbs.
Torque spec on everything could very well be torque it until just before it strips / breaks. If it didn't strip and didn't break, don't worry about it unless it's a critical sealing application such as the head bolts and possibly the cylinder to crankcase bolts. Even intake and exhaust manifolds on these things I wouldn't worry about. You can't even get a torque wrench on half of them anyway. On a car, esp with an aluminum intake, intake manifold bolt torque and sequence may be important too.
Torque specs and sequences are usually more important for the gasket and not for the bolt. I've seen plenty of engineering drawings with a "tighten securely" note.
That's the mechanical engineer in me talking
09-14-2009, 10:12 AM #10
- Join Date
- Aug 2009
- Port Saint Lucie Florida
The bolts used in the yamaha motors are not stretch bolts.... meaning they dont stretch.... Seapoo uses those. They can be reused over and over. Motors built at factory are assembled with airtools .... somewhat preset to the spec. If you look in a spec book all 6mm hardware 8mm hardware ect ect use the same torque setting. It gives the general public a guideline for the big question "how tight ?" . The head is really the important issue and should be torqued properly to maintain good seal without warping it. In regards to the above post yes most dealers assemble motors with little regards to torque values other then the head
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