Broken Exhaust bolt

Joast

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Exhaust bolt is out. Thanks to everyone for all the help and info! Used an Irwin EX-2 Spiral Screw extractor combo with a 7/64 inch bit and WD-40
to soak. A guy at the Lawnmower shop gave me a gasket for the exhaust, but I'm not sure it will work. It is a silver metal that fits good.

Thanks again ! John
 

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Chainlube

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Exhaust bolt is out. Thanks to everyone for all the help and info! Used an Irwin EX-2 Spiral Screw extractor combo with a 7/64 inch bit and WD-40
to soak. A guy at the Lawnmower shop gave me a gasket for the exhaust, but I'm not sure it will work. It is a silver metal that fits good.

Thanks again ! John
I make exhaust gaskets from a Felpro sheet that looks just like that.
 

Chainlube

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That is good to know. I just have to find some better stainless bolts. Pipe bolted right up, and it looks ok to me.
Thanks for the tip on Felpro. John
Don't use stainless on your exhaust, get a couple studs with nuts and lock washers. Stainless doesn't like repeated heat cycles.
 

Nickt919

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Looking back at the photo of the exhaust showing the broken bolt and comparing it to the photo of the lawnmower gasket on the exhaust port it appears the hole in the gasket is a fair amount smaller than the actual exhaust port hole. The smaller gasket hole will restrict the air flow when the engine is running.
If you use the lawnmower gasket be sure the gasket exhaust hole is as big as the exhaust hole on the cylinder. Carefully cut the gasket hole open more to match the shape of the cylinder exhaust port.
 

Joast

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I will look at that when I pull the muffler, but I think that is just the picture.
The gasket hole width on top and bottom is wider than the head port. On the sides by the bolts
the gasket hole width matches the port width real close. My port looks more oblong--the gasket is round.
Thanks john
 

Joast

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So my bike has been running about 15 miles so far, and I think I have an exhaust leak. The muffler flange was bent when I first took it off, and I tried to get it straightened the best I could and ran a file over it to try to clean up the face. When I pulled the muffler off yesterday the gasket showed signs of oil stains just on one area. There also appears to be some fresh oil over the exhaust flange and under the head. Will adding a second stacked exhaust gasket possibly seal this? If not, can someone recommend a good replacement muffler that would be best for a stock 66 cc?
Also I am wondering about the possibility of a head gasket leak over the flange. The bike starts great (without the choke) but seems to run rough at higher rpms; mid-range is fairly smooth. The bike runs out of steam and tops out at about 25 mph on gps. Thanks for any thoughts on this. John
 

DAMIEN1307

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Use this Toyota Highlander O2 sensor gasket instead, available at Toyota dealership or also at autoparts stores such as Auto Zone, Advance Auto Parts, etc.

Here is the current Toyota dealer parts#/stock#, for that gasket...89466-20020-83.

If you shop Autozone, Amazon, etc., its a "Dorman" brand part number ...Dorman 47021...


When installing this gasket, you will need to slightly elongate the holes that go over the studs/bolts...I use a slightly largerbolt to do this through those holes.

You will notice that this gasket has some metal affixed to both sides of the gasket...The side that has the most metal is what goes against the exhaust pipe itself...DO NOT use any gasket sealers with this gasket.
 
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