After changing parts, WOT is slow, and sound louder

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geoldr

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Jun 19, 2011
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I looked into it more, and noticed that on one side there is a slight gap between the jug, gasket, and head.

Problem is, I can't tighten that bolt correctly. It just keeps spinning through. The stud is most likely ruined. Its a long stud, do you know what size it is so I can go to my local hardware store and hope to find one there?
 
biknut

biknut

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Sep 28, 2010
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geoldr said:
I looked into it more, and noticed that on one side there is a slight gap between the jug, gasket, and head.

Problem is, I can't tighten that bolt correctly. It just keeps spinning through. The stud is most likely ruined. Its a long stud, do you know what size it is so I can go to my local hardware store and hope to find one there?
Click to expand...
Sounds like it's probably stripped. You may be headed for a heli-coil insert repair.
 
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geoldr

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Jun 19, 2011
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I watched a youtube video, and the guy drills into there and installs the coils.

Will I also have to do that, or can I just get the coils and put them in there? Or is it possible to just get a higher quality stud from somewhere? I took out the stud to look at it, and it looks pretty stripped.

Also, what is the proper way to tighten the bolts? I have a regular socket wrench that I use, and I tighten it untill it doesnt tighten anymore

EDIT:
I went to my local hardware stores, and they didn't have the repair kit for this size of bolt. Its 8MM with 1 thread count.
I can't find any other ones that fit for this screw. Because it has two different sizes on the different ends of the stud. One is fine, one is coarse.
Out of ideas for now, I can find the helicoil M8x1.25, but the fine 8M is 1 thread count not 1.25
 

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biknut

biknut

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Sep 28, 2010
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Which end seems stripped? The top or the bottom? Is only the stud stripped, or the block? If it's only the stud, then a new stud will fix it. If it's the threads in the block where the stud goes, then you'll need a Heli-coil to fix that.

If you have to make a heli-coil repair then, yes you'll have to drill it out. The way a Heli coil works is, you drill the hole out the the next size. Then you tap the hole for the insert, and screw the insert into the hole with the tool that comes with the kit. That brings the size of the hole back to the original thread size, and now the hole has steel threads that are stronger than than original threads.
 
biknut

biknut

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What may have happened is, if your head bolts are acorn nuts, then the acorn may have bottomed out on the stud. when you tried to tighten the nut, it couldn't turn anymore because it was bottomed out on the stud, so instead of the nut turning, the stud turned, and at the same time stripped. A lot of people have had this problem.

When you put it back together toss the acorns and use regular nuts.
 
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geoldr

New Member
Jun 19, 2011
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California
The bottom part that goes into the block is stripped. I don't think it's stripped inside. I'll have to get a new stud, but none of the local hardware stores around my area carry anything in this size. I tried Lowes, and Home Depot. They told me to go to a machine shop.

If I get a torque wrench, what are the torque settings for these bolts? Ill get rid of the acorn nuts ASAP when I get new studs
 
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geoldr

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Jun 19, 2011
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California
Ok cool, i ordered the head studs and also the dual brake lever just because I've always wanted one.
Can you guys recomend any good torque wrenches?
 
biknut

biknut

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Goat Herder said:
Perhaps get a on line coupon then print it. Go to Harbor Freight locally and get one. 1/4" Click Stop Torque Wrench - 20 to 200 inch pounds

I used this torque wrench in Automotive but primarily love it on small engines.
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I have a set of Harbor Freight torque wrenches. They work fine for me, and were about $10 each. The best one they sell for our purposes is the little inch pound one. Be aware it's 1/4" drive so if all your sockets are 3/8 buy an adapter.
 
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geoldr

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Jun 19, 2011
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California
So the new parts came in today, and I installed them. The head is sealed pretty well I think. Looks good to me. The power feels alot better, I was able to top out at original speeds. So all that is good, except..

After riding for a while, like 20 minutes or so, I noticed it got really loud. Like even at idle its really loud. Im letting it cool off, and ill start it up and see if its still loud or if its quiet again.
 
maniac57

maniac57

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Oct 8, 2011
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You should always retorque headbolts after a few heat cycles to insure they stay tight. also tighten in a criss/cross pattern to spread the load over the head. You may have had your exhaust loosen up from the sound of things...I had the same problem at first and stripped several exhaust studs until I found a set of extra thick nuts...like two or three nuts stacked together. I can't help you find these as they were rattling around in my junk box so I have no idea where they come from. Try threaded rod connectors maybe?
 
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geoldr

New Member
Jun 19, 2011
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California
It was just the way the muffler was. I ended up going with the SBP expansion chamber, and now the motor runs great.

Thanks for all the help guys.
 
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