Author Topic: 16.5 (42) compression  (Read 2262 times)

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Offline Mowtown Rob

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16.5 (42) compression
« on: December 06, 2008, 08:02:47 pm »

I recently picked up a 42cid for next to nothing and want to check the compression. I am assuming it should be over 150 psi? but I am having trouble finding the spec in the archives.

Also, I know everyone hates this question, but I would really appreciate a ballpark figure on what it's worth. I am trying to determine if it is worth having around. If it's worth something I would consider selling it to fund my build, but otherwise I will keep it around for a spare. Here's the skinny on the motor if it helps: Its a briggs flathead 16.5hp (42cid), 1999 year by the date code, and has all the wiring that came off the tractor; seat safety sensors, starter solenoid, key switch, etc.

Thank you very much for taking the time to read and consider my post/questions!

Offline rotten ron

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Re: 16.5 (42) compression
« Reply #1 on: December 06, 2008, 08:29:16 pm »
I would not expect it to have over 100 pounds-atmospheric pressure being 14.7 times the compression ratio,true ratio would be about 7 to 1 =102.9 pounds and that would be with no leakage which is impossible

Offline mowdak1

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Re: 16.5 (42) compression
« Reply #2 on: December 07, 2008, 11:37:49 am »
All the wiring harness is worthless unless someone's fixing their grass cutting machine, for racing application you'll need the solenoid. Otherwise you can wire the ignition switch in if you plan on doing car shows and such, a simple in-line fuse that you can pull is a better option however. If you want to hook up brake lights, you can save the safety switch as well.

As for value, if it runs, compression is good, no known defects, around $250 - $300 on E-Bay. Have seen them go as low as $150, have seen them go as high as $350. Problem is... it's gonna cost you over a hundred bucks to ship it!