Author Topic: CB750 DIY Piston Ring Compressor  (Read 3094 times)

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Offline PGcorky

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CB750 DIY Piston Ring Compressor
« on: January 23, 2015, 05:26:45 pm »
I didn't invent this, just trying to explain for those that may be without a helper and need a tool for this job.
Step 1. Find a 2.5" diameter PVC pipe. Doesn't seem to be very standard, but Lowes had a 10' PVC conduit for about $12.
Step 2. Cut a 3/4" section from the pipe.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #1 on: January 23, 2015, 05:28:21 pm »
Step 3: Mark it to cut out around 1/4" of the pipe.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #2 on: January 23, 2015, 05:29:25 pm »
Step 4: Mark it to cut through the opposite side of the pipe section.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #3 on: January 23, 2015, 05:31:29 pm »
Step 5: Cut out the small pipe section that you marked. I did this at an angle to keep my orientation correct.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #4 on: January 23, 2015, 05:33:05 pm »
Step 6: Cut through the opposite side of your pipe section. I cut this at the opposite angle so that it only goes together one way. Now you have 2 halves of your finished compressor tool.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #5 on: January 23, 2015, 05:34:21 pm »
Step 7: I de-burred mine with the dremel. Taking off the rough edges that might keep it from moving smoothly.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #6 on: January 23, 2015, 05:35:58 pm »
Step 8: Slip on the 3.5" hose clamp. This is about $1.50 at Home Depot in the plumbing or HVAC department.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #7 on: January 23, 2015, 05:38:05 pm »
Step 9: Trim off the excess from the hose clamp. This just makes removing the clamp much quicker once you're done getting your piston rings into the cylinders. I also ran the dremel over this afterwards to take of the sharp edges.
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #8 on: January 23, 2015, 05:40:27 pm »
Step 10: Check the fit! Looks like this will do just fine....
I built 4 of these for a total cost of $18 and I only have about 9 feet of PVC left over....
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200

Offline Bigsam302

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    • 1976 CB750F (915cc) Super Sport
Re: CB750 DIY Piston Ring Compressor
« Reply #9 on: April 16, 2015, 01:48:51 pm »
PG,
That's a pretty good idea.  Were you worried about plastic from the pipe falling back into your engine case? 

Sam
1976 CB750F (915cc) Super Sport: http://forums.sohc4.net/index.php?topic=142578.0

Offline 70CB750

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Re: CB750 DIY Piston Ring Compressor
« Reply #10 on: April 17, 2015, 01:49:26 am »
Clever, but hose clamp alone will do the job too, all it needs is to sand edges a bit.

Offline chewbacca5000

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Re: CB750 DIY Piston Ring Compressor
« Reply #11 on: April 18, 2015, 06:37:54 am »
Step 10: Check the fit! Looks like this will do just fine....
I built 4 of these for a total cost of $18 and I only have about 9 feet of PVC left over....

Making me up a set of 2 I'd be happy to send you $8 bucks.  Mine as well use up the rest of the material.

Offline PGcorky

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Re: CB750 DIY Piston Ring Compressor
« Reply #12 on: April 27, 2015, 06:38:35 am »
PG,
That's a pretty good idea.  Were you worried about plastic from the pipe falling back into your engine case? 

Sam

Sorry for the slow reply, Sam. I've see enough things drop down into the engine case that I ALWAYS have a rag loosely placed to keep that from happening. As far as these go - there isn't any loose plastic since I've deburred them pretty good. And each half of the compressor seems large enough in diameter that it doesn't seem very likely for them to end up in the case.

Paul
1978 CB750f Super Sport
2002 Honda VFR800 Interceptor
Babysitting - 2005 Harley Sportster 1200