Tranona
Well-known member
Bit confused here. First you say it is a 1GM, then a YSE12. although both are Yanmars they are totally different engines (and pumps.
Yanmar 1gm 10 starting backwords!
- Thread starter lexi
- Start date
Tranona
Well-known member
The shims can only be damaged if the pump is removed and then the shims taken off as they tend to get stuck and need prising off. This is what happened with mine as I needed to get the case stripped for blasting and repairing/painting. Measured the shims and bought exact replacements. In normal use there is no reason ever to remove the pump, nor can the shims wear.
You are right the engine can suck water back in when it stops. Not sure replacing the elbow will change the starting problem which, as already suggested is more likely to be poor compression. This could be a poorly seating exhaust valve caused by water getting in.
B27
Well-known member
I would guess the shims can't wear, but the pump, cam, cam follower, camshaft bearings can all wear?
Will that wear generally make the timing earlier or later?
To actually run backwards, would need the 'down side' of the injection cam to drive the pump to inject fuel near the top of what should be the power stroke?
Will that wear generally make the timing earlier or later?
To actually run backwards, would need the 'down side' of the injection cam to drive the pump to inject fuel near the top of what should be the power stroke?
Refueler
Well-known member
ok ... I stand corrected.
lexi
Member
Thanks for answers guys.
lexi
Member
This O Ring YANMAR - 1-3GM - Fuel Injector O Ring - 24341-000260 | eBay
I don't see it after removing injector. Does it sit down in toward heat washer and packing?
I don't see it after removing injector. Does it sit down in toward heat washer and packing?
lexi
Member
That Rubber o ring sits around the injector body to form a dust seal at the top of the hole opening.
Yanmar still want ten quid for a nitrile o ring!
Yanmar still want ten quid for a nitrile o ring!
RogerJolly
Active member
Some idle musings/questions of little use, sorry:
With the engine running backwards, are the inlet and exhaust ports effectively swapped over (which can happen as the fuel doesn’t come in with the air)?
If so, how do we know the engine will normally run the right way?
Is it by tweaking the fuel injection point - later means less likely to start backwards? Guess this will translate to an early injection running backwards, so that would seem to suggest an immediate kick back to normal direction.
Cheers
With the engine running backwards, are the inlet and exhaust ports effectively swapped over (which can happen as the fuel doesn’t come in with the air)?
If so, how do we know the engine will normally run the right way?
Is it by tweaking the fuel injection point - later means less likely to start backwards? Guess this will translate to an early injection running backwards, so that would seem to suggest an immediate kick back to normal direction.
Cheers
dukeofted
Member
As the injector wears, the firing pressure can lower, this would give the same result as advancing the timing and make it more likely to start backwards. The original poster has had their injector checked and it was all ok so it shouldn't be that. It's a shame as I had the exact same issue and it was the injector in my case!
lexi
Member
Nice to hear your comments guys. The short spells of running backwards has destroyed the new air filter. I have good strong compression against the starting handle. I have a suspicion of the combustion chamber under injector also. Genuine Head gasket £80 quid ( ouch) should head need to come off. I might put an aftermarket one on. A new head was fitted years ago and has had freshwater use only since. May try to get the first copper washer off and the heat washer under it first with head still on Have read that the first copper washer should be renewed every time the injector is removed..........mine certainly hasnt! .There is a method of crushing fuse wire in the combustion chamber and measuring the gap. This is all providing my timing marks are lining up ok.
Tranona
Well-known member
Measuring the gap with fuse wire is to check the distance between the piston crown and the head. Too big a gap indicates the con rod is bent. It does not tell you anything about poor compression from leaky valves.
dave_gibsea
Member
I had this problem, its probably air leaking on the fuel system. Change bleed screw plastic washers, the secondary fuel filter housing can be a problem too, I changed mine and its been fine since. A battery that's not giving its full cranking power is also possible cause.
A squirt of easy-start is better than a running backwards engine but its not recommend as proper fix.
A squirt of easy-start is better than a running backwards engine but its not recommend as proper fix.
lexi
Member
Ok boat all cleaned, lets see with timing. Looking into the front timing cover opening( this has one) there are a double set of marks and another single mark about 15 deg above it. My injector is popping fuel at the point in between those separate sets of marks. What marks should pointer be timed to?
lexi
Member
I think the marks I am seeing are a single mark which is the 15DdBTDC and the other mark which looks like a double mark, is probably a mark and then a T below it which is TDC. ATM it looks as though my mark is past the pointer when my injector pops fuel. I will clean marks again with some solvent and check again to make sure. I think the marks are the same through the window in bellhousing as they are at other side when starter is removed. I think you could time it without removing Injector or breaking any fuel lines.
You can hear when the Injector pops in there quite easily. It sounds like a stiff spring giving a loud squeak.
You can hear when the Injector pops in there quite easily. It sounds like a stiff spring giving a loud squeak.
lexi
Member
It turns out that my injector is firing halfway between TDC and 15deg BTDC. That equates to 7 deg out! I have checked with starter out, and it is the same through the window facing aft. The shims only move timing 1deg. If this was a car you would think cam belt had jumped a tooth. Could the pump be a tooth out in there?
lexi
Member
Just to come back on this one. I timed the fuel pump at the delivery valve rather than the injector. It seemed the same. On reading about the importance of delivery valve torque, I did it up to the 30 ft lb nominal figure. It did tighten a touch before my wrench clicked. It now times around the mark now with fuel just coming up the valve. With this done and new elbow I have at least some hope it may start now. Try later in week.
14K478
Well-known member
The Doxford big ship diesel engine was well known for starting in the wrong direction. Big ship crosshead diesels are direct coupled, with no gear box or clutch, so you stop the engine and start it again, going backwards, to reverse, but the Doxford would sometimes start in the direction that suited it at the time. Piers and jetties around the world, but particularly in the South Pacific, the stamping ground of two British companies, Bank Line and CNCo, both of which favoured Doxfords, bear witness to this...
Biggles Wader
Well-known member
Message to head office---------Vessel contacted wharf at Yandina------Demolished same.
14K478
Well-known member
This snap of a CNCo C/K class (with Doxford!) is thought to have been taken at Yandina, but nobody, peering back to the 1960´s through a haze of Gordon’s and Schweppes, is quite sure, now!Message to head office---------Vessel contacted wharf at Yandina------Demolished same.
Biggles Wader
Well-known member
Looks very much like Yandina. I went there as a teenager and steered the ship alongside as part of my steering certificate. No pilot and no tugs there, just a bloke in a rowing boat to take a line ashore. The wharf was tiny and we would winch the ship fore and aft to get it alongside the required hatch for loading copra(very slowly). I still can't quite believe that people like me used to get paid to amble round the world and visit places like that. It couldnt last, and it didnt!