what do you see when you remove compression release??

[johnle712]

Hi all. What do you expect to see when you look straight at the cyclinder head pass the thread hole after the compression release has been remove? Will the bike start if one of compression release has been remove and unplug?

I just found out my k9 missing rear compression release so i am trying to find out if it broke off and there still part in there or it has been completely remove. My bike will start and ride ok, however i do hear some air escape from it. Thank you.

john

 

[KaptinAmerika]

If you can put a screwdriver down into the hole then it is missing completely. Otherwise it broke off at the nipple and you will have to get that piece out first. The bike will start but if the hole is wide open it will run really sloppy. If you can hear like a hissing sound then part of the release is probably still stuck in there

 

[john sachs]

Look into the hole. You should see about a half inch of PROUD threads about 1/4" down into the hole if the whole release is missing. Also, if the whole release is missing and you don't see the threads, the head is junk. I haven't figured out how to replace the threads. :bang:
John

 

[awg]

Can any of the parts fall into the cylinder therefore damageing the motor?

 

[john sachs]

Can any of the parts fall into the cylinder therefore damageing the motor?

NO............

 

[Mr. Wright]

If you can't get the piece out, or if it's gone and the threads are damaged, sent the head to me, along with a new compression release, and I'll see if I can save it.
Send me a PM if I can help.

 

[johnle712]

Seems like Compression release has been completely remove

If you can put a screwdriver down into the hole then it is missing completely. Otherwise it broke off at the nipple and you will have to get that piece out first. The bike will start but if the hole is wide open it will run really sloppy. If you can hear like a hissing sound then part of the release is probably still stuck in there

@Curtis: Yes. I can put a screwdriver down into it.

Look into the hole. You should see about a half inch of PROUD threads about 1/4" down into the hole if the whole release is missing. Also, if the whole release is missing and you don't see the threads, the head is junk. I haven't figured out how to replace the threads. :bang:
John

@John: i can still see the thread hole.

If you can't get the piece out, or if it's gone and the threads are damaged, sent the head to me, along with a new compression release, and I'll see if I can save it.
Send me a PM if I can help.

@Shannon : Thank you for your offer.


OK. It is completely missing. All i need is a new CR put in there. Wow..what a release. My main concern was when i look into the hole i saw what look like an o-ring at the bottom so i thought that some part must still be in there. Come to find out from S&S tech help line that there is a grove at the end of a hole and with carbon build up make it look like an o-ring. The grove is there to prevent anything fall into. Also it is 1/2 an inch deep from the thread to the bottom of the hole if CR completely remove. So all together : i can put a screwdriver into the hole, it is 1/2" inch deep and i still can see the thread hole.

Thank you Curtis, John and Shannon for your times.

 

[johnle712]

BTW, i was told by a local mechanic that if CR completely missing, you will see pistons...lolz. Not true.

 

[Mr. Wright]

I guess that's were the term, "Lucky Dog" comes from. Glad it worked out for you.

 

[john sachs]

BTW, i was told by a local mechanic that if CR completely missing, you will see pistons...lolz. Not true.

That's funny. He must have BETTER than X-ray vision. :loony: The hole in the chamber is at an angle, and bisects the passage that runs through the exhaust port.
John

 

[reloaderbmg]

Look into the hole. You should see about a half inch of PROUD threads about 1/4" down into the hole if the whole release is missing. Also, if the whole release is missing and you don't see the threads, the head is junk. I haven't figured out how to replace the threads. :bang:
John

time serts!

 

[john sachs]

time serts!

Put a compression release in one hand, and very carefully look at it, and the receiver hole in the head. I doubt ANY type of Helicoil/insert will work. Your dealing with a PROUD thread in the head with a set clearance for the compression release. Also the receiver hole od may be too thin to accept a drill/tap combination. Plus you would ned a larger sealing washer. :bang:
I had a customer that blew a compression release, threads as well, out of the head, and S&S warranted the head.
You also have to be very careful when you install a compression release in an S&S head that the washer is seated perfectly, and not able to move from that position. If it does, and you tighten it you'll press the threads out of the head. You can also press the threads out by overtightening the release. I use 27 ft. lbs. and No Loctite.
John

 

[johnle712]

You also have to be very careful when you install a compression release in an S&S head that the washer is seated perfectly, and not able to move from that position. If it does, and you tighten it you'll press the threads out of the head. You can also press the threads out by overtightening the release. I use 27 ft. lbs. and No Loctite.
John

Good info. Thanks John.

I guess that's were the term, "Lucky Dog" comes from. Glad it worked out for you.

Well i am not so lucky.

After remove the gas tank and rocker cover, i discover the bottom half of the nipple or possible less then half still in there. Any suggestions or recommendations to get that little piece out? :bang:

 

[john sachs]

Put a magnet to it. It should lift out. 1 other thing you can try, put that cylinder at TDC compression stroke(valves closed), remove exhaust pipe, and blow air in the compression relief hole in the exhaust port ..... should launch out, that might work.
John

 

[francoblay1]

How it went? sorted?