[pipes]

Hey everybody! Sent my heads off to Big Boyz to get redone on my '99 Nighttrain. While taking the heads off, I broke the seal on the base gaskets and figured I might as well change them, also. What's easiest, pulling the cylinders off the pistons or leaving the pistons in the cylinders and pulling the pins out. I don't have any specialty tools to do this, although I'm sure I can round up a ring compressor. The motor only has 9,000 miles on it, so I am not going to replace rings. Also, should I scrape off all the carbon build-up on top of the piston and if so, what do you guys use? Thanks alot for any advice!

 

[BikeMike]

I would leave the pistons in the cylinder so you do not distrub the rings, I have done this several times with no problems, make sure you place a clean rag in the top of the crank case when removing the circlip. Any time you remove the head you must/should replace the base gasket. good luck

 

[pipes]

I would leave the pistons in the cylinder so you do not distrub the rings, I have done this several times with no problems, make sure you place a clean rag in the top of the crank case when removing the circlip. Any time you remove the head you must/should replace the base gasket. good luck

Do I need any special tools to do this? Also, should I scrape off the carbon build-up or leave it alone? Thanks for the reply

 

[BikeMike]

I was able to pull the piston pins out after removing the circlips, they were snug but able to remove without using a wrist pin puller. The circlip can be carefully removed with a small pick or flat screw driver, be careful do not scratch the piston. The challege with removing the carbon from the top of the pistons with them in the cylinder is not getting the carbon in the rings/grooves. You will have to move the piton up and down in the cylinder during this procedure just do not rotate it during the process, you can pull the piston to the top of the cylinder to remove the carbon again do not go so far that the upper ring comes out. Idealy a wire wheel works well for removing the carbon again this is difficult with the pistons in the cylinders, I would not worry about a small amount of uniformed carbon on the top of the piston.

 

[baggersport]

Removing the gasket can be tricky as they are stuck to the cylinder base very well usually. I use a small acid brush and gasket remover sprayed into a cup and applied with the brush, be careful not to get any on the powdered texture finish and scrape the gasket a little bit at a time applying more remover as you go. You're trying to get it off without damaging the gasket surface (aluminum). Use new single edge razor blades and don't flip them over once you use them (burrs will be on the other side). Don't expect to use just one blade, use as many as needed to keep a sharp edge.

 

[pipes]

Thanks alot for the advice, Mike. There is quite a bit of build-up, so I think what I will do is after I get the cylinder and piston removed (piston still in cylinder), I will tip it upside down and scrape it off to prevent any debris from falling into the grooves. Again, thanks for the advice.

 

[pipes]

Thanks, Baggersport, I was wondering about that, also.