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DaughtryLC
02-24-2007, 05:40 AM
Using oil last season, But not smoking. I took off the head and with the piston up I can run a .012 gauge around the piston. Replace or Rebuild?? or any suggestions. I believe I can get one of these engines for around $600

Bill Kapaun
02-24-2007, 06:31 AM
It's the rings that do the sealing. A piston will have "some" clearance when cold so it has room to expand when hot.
Oil could be getting sucked by the valve guides.
Unless it's fouling the spark plug or fogging the mosquitoes, I'd just keep adding oil. It's a lot cheaper.

A.D Services
02-25-2007, 09:20 AM
but if it blew up then i would just replace the whole thing instead of rebilding it.

khouse
02-25-2007, 03:22 PM
There is more clearance in the land above the compression ring due to the high heat at the top of the piston. (extra expansion room) This is normal.
How much oil is it using? All engines use oil. If they didn't they would seize up and the seals would burn up.

DaughtryLC
02-25-2007, 08:19 PM
.5 qt per hour, It was used Commercial(by a big out fit) for two yrs. and I had it three yrs. No hr. meter??!!

khouse
02-25-2007, 09:09 PM
You should be seeing smoke at that rate of consumption. Do you have a leak somewhere?

DaughtryLC
02-25-2007, 09:18 PM
Just at start up and I don't know if this is anything but the fumes from the exhaust kill my eyes. Also I switched to synthetic and it helped for awhile and it went back to the same old thing.

thecrankshaft
02-25-2007, 09:19 PM
Do you see any cross hatch in the cylinder bore? Most of those engines that I see that are smoking and using oil are worn out from dirt ingestion from lack of air cleaner maintenance. I have seen top compression ring end gaps over a tenth of an inch (0.100") - spec being no more than 0.031" on a used bore.

DaughtryLC
02-25-2007, 09:22 PM
Cross hatch?? help me out also 60 psi compression

DaughtryLC
02-25-2007, 11:43 PM
Bump, Bump

lucforce
02-26-2007, 04:31 PM
First you can not check the compression on an engine with an automatic compression release.

Cross hatch is the pattern left on the cylinder wall from honing. The "hatch" is a series of minute scratches in the wall left from the stones on the hone.

DaughtryLC
02-28-2007, 09:30 PM
First you can not check the compression on an engine with an automatic compression release.

Cross hatch is the pattern left on the cylinder wall from honing. The "hatch" is a series of minute scratches in the wall left from the stones on the hone.

Are you saying I can not check the compression on this engine?

thecrankshaft
02-28-2007, 10:04 PM
The compression will be low because this engine has an ACR (automatic compression release). This is operated by a flyweight on the camshaft, and opens the exhaust valve slightly during the compression stroke to allow easier starting. The ACR is only activated under 600 RPM, and you will not get the engine to spin faster than this when you are cranking it over to do a compression test.

barnard
02-28-2007, 11:18 PM
in answer to your first question,I'd replace.

Jay74
03-01-2007, 07:08 PM
Perform a leakdown test to make sure your valves are ok. If they're good then replace the rings.

Jason

topsites
03-03-2007, 04:56 PM
I would replace it as well, you can probably sell the old one for $200 - $400 depending on its model number.

I had a similar issue with my CV15T-41624 just didn't have the power she used to have, never checked compression but I was pretty sure it was the engine, you could just hear by the way it was running...

Lo and behold, the 41624 is an $1100 engine because most places don't actively carry it anymore, but I ordered the 41629 for just under $600 w/ the shipping and put it in today, works great!

It took somewhere around 4 hours, it's not too bad but you need a gear puller to get the pulleys off, some kind of wd-40 or liquid wrench or some kinda rust loosener, and some patience... But overall, I dare say it was slightly easier than the belt-drive's Tecumseh transmission.

Don't forget to drain the oil from old before you start (I did not do this and oil got in the carb), and do NOT forget to fill new with some fresh before you run it (this I did do lol).

DaughtryLC
03-05-2007, 09:46 AM
Thanks guys,
I ordered a new engine last week!, After some thinking I decide there's no time for this mower to be down so early in the season!