what do u think

bigmike35 · 16 February 2006, 19:46

i have an engine just having it servised and been told compression down on 1 piston 115,115,115,75 i was told when i obtained engine that it was working and in fab condition when last used,the engine has been stood for 5 years not been started nothing when i got it home i put a battery on and got it started 1st time i was talking to a macanic explained what the problem was what he said every engine is basicly the same what i would do is take it out on a lake and give it a dam good blasting at lest a tank full of petrol and check it after what do u think?

Rogue Wave · 16 February 2006, 19:48

seems good advice even if the engine is shagged then at least you'll have some fun finding out!

le_forban29 · 16 February 2006, 20:08

After five years in a shack, you may have one of the set of piston rings stuck, a good blast may help

Hightower · 16 February 2006, 20:11

Sounds like good advice from Rogue.

Try to go out with another boat, just in case or an Aux. outboard.

Hugh Jardon · 16 February 2006, 20:45

the only problem is that if it has been stuckaround for 5 years you might have some corrosion on a shell or bearing that would only show itself after a matter of time, i would go out and have a lot of fun but make sure you are close to safety or not in jeopardy if the engine failed, perhaps and aux with you or another boat, if after a tank of fuel and a good few hours of use it is fine and no knocking or ratling then you may well be fine!

speaking from experience here!!

one of my engines blew!

boatster_sr4 · 16 February 2006, 21:26

How about a decarboning? Some solvents you put in the fuel tank and idle through the motor. Supposed to remove carbon deposits on the rings and piston crowns etc.

jwalker · 16 February 2006, 21:45

Quote:

Originally Posted by bigmike35

...take it out on a lake and give it a dam good blasting at lest a tank full of petrol and check it after what do u think?

I wouldn't do that. Just use it normally for a while and give it time to settle. Recheck the compression after an hour or so running. It sounds as though you may have a fairly good motor and it would be a shame to ruin it for the cost of a ring set and head gasket.

Nos4r2 · 17 February 2006, 03:50

unfortunately those engines don't have head gaskets-they have blind bores so it's a long job to change the rings. If you're going to try and free the rings by running it Mike put a full can of Redex in the fuel tank and then take it out for the day but not at FULL throttle. Redex clears out crap that sticks to rings rather well.

jwalker · 17 February 2006, 11:07

Quote:

Originally Posted by Nos4r2

unfortunately those engines don't have head gaskets-they have blind bores so it's a long job to change the rings.

OK but no difference realy cos you have to undo the bigends anyway. However, my point was not to be wreckless and cause unnecessary damage.

Rogue Wave · 17 February 2006, 11:24

Quote:

Originally Posted by jwalker

OK but no difference realy cos you have to undo the bigends anyway. However, my point was not to be wreckless and cause unnecessary damage.

yes I agree I could have been a bit more cautious in my post. After all us Welsh have got to stick together

Kernow Buoy · 17 February 2006, 11:36

Quote:

Originally Posted by Rogue Wave

After all us Welsh have got to stick together

Not at all, my perception of Welshmen has risen dramatically, I had the pleasure of a welshman's company for 2 hours or so recently, we'd never met before and it was the best 2 hours I've had for many a year, I really really enjoyed sitting next to the guy.
We were at twickenham!

Rogue Wave · 17 February 2006, 11:42

you never beat the Welsh bud sadly on some occasions you do score more points.

Kernow Buoy · 17 February 2006, 11:51

Actually we did get on well, he applauded the English, I applauded the welsh, unfortunately half way through the second half his hands started bleeding

Rogue Wave · 17 February 2006, 11:53

an old one but good one

Kernow Buoy · 17 February 2006, 12:20

I was congratulating myself on making that one up!

Rogue Wave · 17 February 2006, 12:33

I'd never heard it before and I thought it was quite original and funny, which leads nicely to my original point about not beating the Welsh

Kernow Buoy · 17 February 2006, 13:18

Quote:

Originally Posted by Rogue Wave

I'd never heard it before and I thought it was quite original and funny, which leads nicely to my original point about not beating the Welsh

Andy Gee · 17 February 2006, 13:56

I had a similar problem about 8 years ago, bought a boat fitted with twin 75hp Mariners that had been stored for about 4 years. The port engine was down in compression, ran is gently for a couple of hours and the compression came back

, but after about another 100 or so hours the thing started knocking. Got it stripped and the mains bearings were shot, all rusty along with the shells. Apparently this can be quite common with engines that have been left for a while.

Best of Luck
Andy

Hugh Jardon · 17 February 2006, 14:17

the fault you had is similar to mine however my big ends went within a few hours rather than 100 or so. i would venture to suggest that if the bearings or bearing surfaces were visably quite rusty etc then the engine would not last very long at all. however minor corrosion will decrease the life of the bearing/shell and there is no exact science on how long it will go on for.

its all a big gamble and minor damage from corrosion may not show itself in a failure for some hours so it is just best to bare this in mind when putting the boat/engine thru its paces.

if a strip down and replace of shells and rings or at least checking them was an option then this would be a good way forward for sure but not everyone is able to do this themselves and getting a dealer to do it is costly.

good luck

Quote:

Originally Posted by Andy Gee

I had a similar problem about 8 years ago, bought a boat fitted with twin 75hp Mariners that had been stored for about 4 years. The port engine was down in compression, ran is gently for a couple of hours and the compression came back

, but after about another 100 or so hours the thing started knocking. Got it stripped and the mains bearings were shot, all rusty along with the shells. Apparently this can be quite common with engines that have been left for a while.

Best of Luck
Andy

jwalker · 17 February 2006, 15:36

Quote:

Originally Posted by Hugh Jardon

...if a strip down and replace of shells and rings..

Hugh, it won't have shells as in a 4 stroke. It'll be needle rollers and they run between the bigend of the conrod and the crank. If there's severe rust, it's a major job. If the crank and rods are only minorly damaged, it is possible to hone them and bring them back to life relatively inexpensively if DIYing is an option. Needle rollers can be purchased from bearing suppliers in quantities of 100 for not too much money.