179580
Well-Known Member
You will feel it when it comes on compression. Should just about stop dead.
Fuel problem
- Thread starter Thedigger
- Start date
Refueler
Well-Known Member
YES ... if it turns easily - then check Decompression lever ....
Only turn slowly - you are not trying to start it .. just to feel if it has compression.
Thedigger
Active Member
Richard,
just come down to the boat and I can turn the crank by hand so looks like I got no compression. Does this mean the end of the engine or is there some fix I can do?
Refueler
Well-Known Member
[70521]
Well-Known Member
I know I am a cynic, but feel there is a wind up going on here and I don't mean hand cranking the engine.
Refueler
Well-Known Member
Are you sure decompression lever is not stuck ... is closed fully ?
A small engine like this - possibly you could turn it by hand fully over 2 or 3 complete turns ... BUT at one particular spot - it should get seriously hard as you try to turn piston through top dead centre (compressed point) needing serious effort to turn.
I can put a large adjustable on the crank of my 4 cylinder Perkins and turn it through compression - very hard - but I can do it.... I usually do that after winter to make sure engine turns easy for starter ..
Thedigger
Active Member
Can’t get one for the next few months
Thedigger
Active Member
I’m wondering if the fuel is blocked at the jet point just before it enters the cylinder. If no fuel is getting through then that would cause low compression? I can see fuel at the injection pump and there was signs of air so primed that out. Is it possible the fuel is blocked at the atomiser? So no fuel entering the chamber would result in low compression?
Refueler
Well-Known Member
Any diesel mechanic will do ... seriously. Most boat engines are derived from land based engines ....
I had trouble with my Perkins one year .. she just would not run properly. Blew through lines ... changed filters ... sucked out tank crud ... bled injector lines etc etc etc.
Pal of mine is supervisor at local Volvo Truck service ... he came and looked ... within couple of minutes he asked for spanners ... removed injection pump ... took it to his 'shop'.
Next day returned fitted it ... engine has run beautifully ever since.
What was it ? Perkins do not tell you that there is a small thimble filter ... you cannot see it ... you cannot get at it without removing the whole pump and putting on the bench.
Refueler
Well-Known Member
Simple answer ... NO. Compression is a physical attribute of the piston compressing at top of cylinder stroke. Has nothing to do with fuel in or not.
TrampBg
New Member
To check the compression you don't need mechanic. You can do it yourself. Just buy Diesel Engine Compression Tester Kit (about 28GBP) and follow the instructions.
Easiest way is to check the compression trough glow plug holes- they are standard and compression tester kit comes with a number of adapters with most common sizes.
Plenty of videos on Youtube as well.
Lost compression is sure evidence of a problem but in most of the cases is not the end of life of the engine. Could be caused by stuck piston rings.
Easiest way is to check the compression trough glow plug holes- they are standard and compression tester kit comes with a number of adapters with most common sizes.
Plenty of videos on Youtube as well.
Lost compression is sure evidence of a problem but in most of the cases is not the end of life of the engine. Could be caused by stuck piston rings.
LadyInBed
Well-Known Member
From what I remember about my 1GM there was a sprung loaded decompression leaver near the top of the engine. I can't now remember how I stopped the engine but it certainly wasn't by using above said leaver.
Dellquay13
Well-Known Member
my 1gm10 has no glow plug to remove to fit the tester.
A free check for substantial compression is hand turning a few full rotations, if you don't have to strain at one particular point every other full turn, it's not right. A chalk mark on the fly wheel can help to confirm the resistance is always at the same point of rotation
there are plenty of sites on the net with 1gm10 manuals which have layout drawings to show where things like the decompression lever can be found.
RichardS
N/A
Forget about fuel. You either have something which can probably be easily fixed like a valve stuck open or a decompression lever stuck open, or something which needs more specialised knowledge.
Do you know anyone who could take a look at it as it should only take a few minutes to find the cause of the lack of compression?
Richard
Thedigger
Active Member
Asking a mechanic to come out to see an old boat worth nothing is not easy unless he is a pal. I guess I got no pals who are diesel mechanics. Getting trades men in this economy to look at a wee job is hopeless. Trades people are looking for big bucks. I spoke with one marine engineer and he said nobody is booking new appointments at moment. There is a 3 - 4 month wait so guess I’m going to try and figure this out myself with help from the forum and utube!
Thedigger
Active Member
I can safely say I have low compression.
LadyInBed
Well-Known Member
Have a look at this link
Bleeding a diesel engine
It's about bleeding a 1GM10 but it might give you a clue about leaver positions.
Also google 1GM10 and look at images, you might find something relevant that you can follow the link to.
Bleeding a diesel engine
It's about bleeding a 1GM10 but it might give you a clue about leaver positions.
Also google 1GM10 and look at images, you might find something relevant that you can follow the link to.
Spirit (of Glenans)
Well-Known Member
The ES acts as a "fuel", give one or two ignitions. It will "pop" if there is decent compression, even in the complete absence of actual fuel oil.
I should also stress to the OP the advice given above, to turn off the raw water seacock so as to prevent flooding the exhaust with seawater which could have expensive consequences, but to turn it on immediately in the event of the engine actually firing.
I think perhaps the OP should give us some background info e.g. type of boat, has he seen it running etc.
Last edited:
Thedigger
Active Member
I’m took the cylinder head off. Replacing gaskets and notice the exhaust exit hole is badly clogged up with carbon deposits. Cleaning up where the head meets the block, replacing zinc anode. I notice one of the head bolts was a bit loose. I’m groping in the dark here
LadyInBed
Well-Known Member
If you have the head off, reseat the valves using Valve grinding paste and a suction cup stick.
Google how to grind in valves if you don't know how.
If the valve is causing the lack of compression, that should sort it out. A wire brush on an electric drill will help clean out the chambers.
Google how to grind in valves if you don't know how.
If the valve is causing the lack of compression, that should sort it out. A wire brush on an electric drill will help clean out the chambers.
