ysb8, its drives me crazy!!

[Halifax Sailor]

This issue started last season, no start when launching, finally started after 15 minutes countinuous tries. Was hard start when back at the marina so this is what I have done since. Launching again Monday for another season, somewhat same issue. Slow start, 30-90 seconds before it catches and slowly starts. It wants to start, gives thoise bumps like an almost start then back to just winding. It used to start 10 secs. I know that 30 secs doesn't sound long but the admiral needs a quick start like it used to, for her comfort.

1) replaced all fuel lines
2) new filters
3) drained old fuel, made me cry at the price of it but thought it might be the issue, so new fuel in tank, old fuel had no smell! thought that was a little weird.
4) new exhaust elbow and hose
5) rebuilt injector, third party so I know it's correct. Even had them check it again, proper yanmar setting, torqued the injector to 15 ft/lbs. new crush washer when installing.
6) blew out all fuel lines, including tank vent to ensure no blockages
7) rechecked valve lash, it's correct
8) checked the ball valve in racor filter, its clean and working, prime pump works as well
9) checked fuel pickup in tank, clear and working
10) turned on elec fuel pump, fuel at hp pump, no bubbles
11) no leaks in hp line

I have an elec fuel pump that filled filters and lines no issue.
When it starts, it runs smooth like it never has before, no smoke ( nothing out of the usual for a diesel), however the slow starting is making me crazy. A fwllow club member jsut rebuilt/calibrated his hp pump on a 2gm. Waiting for him to install so maybe thats my issue? grasping at straws here.

Any idea would be helpful

[ranger58sb]

How old is the start battery? And what CCA is it (was it, when new) compared to whatever it is your engine spec needs?

Or... as a test, add another known-good battery to your start bank, see if that makes any difference...

-Chris

[capblasters]

Ranger58sb beat me to it. From what I can see, you got all the fuel issues covered so next step is compression rate. The compression rate has to overcome the temperature losses for the fuel-air moisture to reach is autoignition temperature. A weaker battery might be able to get the pistons moving but not fast enough to get that temperature up. This is also why these engines have glow plugs or elements to preheat the cylinder chamber or fuel. Are those working?

Graham
Canadian expat living in Australia

[Halifax Sailor]

No glow plugs, way too old for those, 1978 and single culinder. Have tried starting with 3 batteries and charger on line so lots of power. Two batteries are 550 and one is 650. all seem to hold charge and turn engine over with no issue. All three batteries will fill up and turn charger off so I am assuming they are holding charge. Have tested them and over two days they do not fall in voltage. This is why I am mystified. Grew up on a farm and we used to use ether on tractors cold start, perkins diesels. Do not want to do that, small engine single cylinder. Last resort if I was in trouble. Might have to try a new starter battery.

[ranger58sb]

Originally Posted by Halifax Sailor

No glow plugs, way too old for those, 1978 and single culinder. Have tried starting with 3 batteries and charger on line so lots of power. Two batteries are 550 and one is 650. all seem to hold charge and turn engine over with no issue. All three batteries will fill up and turn charger off so I am assuming they are holding charge. Have tested them and over two days they do not fall in voltage. This is why I am mystified. Grew up on a farm and we used to use ether on tractors cold start, perkins diesels. Do not want to do that, small engine single cylinder. Last resort if I was in trouble. Might have to try a new starter battery.

It's possible that old batteries will SEEM to show themselves holding a charge... but as capacity has fallen off over the years, the amount of that charge they'll hold may have diminished over time.

And a battery with original CCA of 650 may not be giving you that anymore.

What is minimum CCA required, as specified by your engine manual?

Try a load test on some of your batteries? Battery stores will often do that for you...

Although, if you had a not-completely-dead battery hooked up with a decent sized charger TOO and it still balked at starting... I'd maybe begin to go back to fuel/air issues unless a load test gives you something useful to think about. HP pump balky?

-Chris

[Compass790]

I agree with everything that Wotname said in his PM.
Might be time for a compression test if the starting tricks Wottie gave you dont work. I'd leave the injection pump till last resort. I have a different injection pump so not au fait with your style.
Only trick I can add is hair dryer in air intake whilst cranking if you have access to shore power. If it starts a lot faster with hot air it points to low compression.
I feel yr pain

[Wotname]

I gotta make this clear - a good battery is no guarantee you don't have an electrical problem. You can have the world's biggest and best new battery and still have an electrical problem. The battery is only one part of the electrical circuit.

The other parts are the conductors and the load. In other words, the wiring (positive and negative), the switch(s), the solenoid, the starter motor. A fault in any one of these areas will prevent fast starting.

You first need to confirm if you have a fuel issue or a compression issue.

If you have confirmed the fuel side of things is OK, then you need to concentrate on the compression side of things.

On the compression issue, you first have to determine if it is electrical or mechanical problem. The use of the decompression lever is your friend here and will help to determine if you have a problematic electrical starting circuit. Remember this engine can be hand started using the decompression lever if you have the hand starting gears fitted.

[grantmc]

Not clear as to exact symptoms other than hard to start. So a YS8 series (very very old now, and super basic engines) all share a common issue (as do the YS12s for that matter). Raw sea water cooling. Horizontal cylinders. And over time there's a minute build up of sea water in the chamber that sits at the low side of the cylinder and ever so slowly erodes the the cylinder head gasket. Reduces compression and then hard to start.

The gaskets need to be replaced as a part of preventative maintenance every 500 hours or so. I humbly suggest that a replacement cylinder head gasket will solve your problem OP. I spent a great deal of money some years back to gain this understanding.

[Wotname]

Grantmc is correct. It is certainly possible the engine has a corroded head gasket for all the reasons Grant notes and this is one possible explanation for the reported symptoms. It could be correct explanation.

When trouble shooting, there are several different techniques and the 'proper' technique is different for different people. One can take the shot gun approach which is repair/replace everything until the engine runs. Another approach is to make an educated guess and look in that area until you find the fault.

The approach I prefer is the diagnostic approach and do a series of simple cheap tests to isolate the area where the fault lies.

1. Determine if fuel, compression or (unlikely) air related.

Using a small atomiser bottle filled with diesel, mist some diesel spray into the air intake while cranking. If fires quickly, then the fault is in the fuel system. If it doesn't fire, it isn't fuel related so likely to be compression related.

2. If compression related, then determine if it mechanical or low starting rpm (i.e. electrical).

To test for low starting rpm, spin the engine over decompressed for 5 secs and then while keeping the starter motor engaged, recompress the engine. If it now starts quickly (after recompressing), then the fault is likely to be electrical in nature. If it still taking a long time to start then likely to be a mechanical low compression issue.

Pull the head and inspect head gasket, valves and liner or do a compression test if you have access to a compression tester suitable for a diesel engine.

Doing the above tests only takes a few minutes and should point you towards the problem

[Halifax Sailor]

I want to thank everyone for the input. I launch Monday so will start on the above list once in the water. I can do all the tests and possible repairs in the water so would rather be in than still on the hard. I will keep you informed. Again thx for the advice and encouragement.

[skipmac]

Hi HS.

Maybe I missed it but wasn't clear to me that when you try to start the engine that when you engage the starter the engine turns over fast or slow when it isn't starting. To me that's the test of the starter and battery, how fast the engine goes round and round when trying to start. If it turns over fast but isn't firing then I would look at something besides the starter or battery.

Had a similar problem and tried this and that and checked different things. Determined the problem was in the fuel supply (air leak) but couldn't tell where. Finally went through the fuel supply systematically starting at the engine and working my way back.

Get a quart size more or less, very clean bottle. Emphasis on clean. Should rinse it with diesel then fill it with clean, fresh fuel. First make sure there is fuel from the secondary filter all the way to the injector, then take the hose that leads to the injector pump (make sure the hose is clean so no dirt or dust can fall off into the fuel) and put the hose into the bottle and see if it cranks and runs. If so then work your way step by step back to the tank and see if the problem reappears.

[crashley]

Immediately Before trying to start bleed the injector and then immediately try for a start sometimes the injector will leak down or back to the pump

[basssears]

Originally Posted by grantmc

I humbly suggest that a replacement cylinder head gasket will solve your problem OP. I spent a great deal of money some years back to gain this understanding.

I can't help with the OP's particular issue, but I humbly submit that the sort of comment here is the best of CF and honestly the internet... freely offered very specific comment, on topic.

Awesome.

[hjohnson]

Had something like this happen on my 1GM10. Turns out the faulty bit of the fuel system was the Gauge Sender in our tank. Gauge was reading 2/3 of a tank, when it was in fact bone dry. Only figured this out after replacing all the fuel lines, the filter system, and the lift pump on the engine.



But it looks like you have that covered, so that's not it.

[Lepke]

Any heat like a hair dryer pointed into the intake will help a balky engine start if it's compression related. If that helps, put in a block or pan heater or figure out where to put glow plugs in the intake.