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Engine trouble

Printed From: Laser 28 International Class Association
Category: Laser 28 General
Forum Name: Maintenance
Forum Description: All the things to care for your boat
URL: http://www.laser28.org/forum/forum_posts.asp?TID=682
Printed Date: 10 July 2020 at 3:38pm
Software Version: Web Wiz Forums 11.03 - http://www.webwizforums.com


Topic: Engine trouble
Posted By: fatjohnz
Subject: Engine trouble
Date Posted: 14 October 2014 at 10:08pm

The kill switch position of the ignition stopped working reliably. Since it was intermittent, I replaced the ignition swith. It still only works occasionally. The solenoid is on the top rear of the engine right? The metal tab on top is loose so I was going to try to solder it. In the mean time, we shut down the engine with the lever behind the air cleaner.

The engine has not been starting as of late although we have plenty of cranking power. It takes a shot of diesel starting fluid to get her going after sitting, even if she's warm. And it has also stalled once or twice after the fluid burns off. I'm thinking there is a leak in the fuel line letting air up to the injector. I'm planning to change the fuel filter and then loosen/tighten all the fittings from the pump to the injector.

Today when I checked my oil, it was milky. Could the starting fluid be generating too much pressure in the cylinder and causing a temporary gasket fail? Once started , the engine has been running fine. I'm going to change the oil for starters.

Any suggestions on how to diagnose and fix this baby? thx, js   



Replies:
Posted By: Bill Layton
Date Posted: 15 October 2014 at 12:52am
Milky oil means a blown headgasket and or a warped cylinder head. Don't run the engine with milky oil as you will cause further damage if it runs for too long. This certainly causes your other problems. If your engine has plenty of cranking power then not sure what would be wrong with the ignition switch. Time to get that head off and in for service.


Posted By: fatjohnz
Date Posted: 20 October 2014 at 9:27am
Hi Bill, Would you suggest I send the head to Crinmar for evaluation/service? I guess the other option would be to just have it planed and re-install with a new head gasket... I don't have the tools to check the valve guides and seat myself... thanks, John


Posted By: Bill Layton
Date Posted: 20 October 2014 at 9:31am
You could do that but any engine shop should be able to pressure test the head and verify if it overheated and became warped or cracked etc. Crinmar sends it out to someone else for this service.


Posted By: fatjohnz
Date Posted: 20 October 2014 at 7:32pm
I removed the 4 nuts, exhaust, fuel, and water. Then cracked the joint by pounding a putty knife into it. It still didn't release all the way. Hopefully there is nothing internal holding it up and I can go after it with a flat bar? I didn't have the heart to pound a screwdriver into the joint. thx, john


Posted By: Bill Layton
Date Posted: 20 October 2014 at 8:48pm
Yeah some heads are seized in place by the carbon buildup on the studs. I've done approx. 12 head jobs and 50% of them are like this. I made plastic wedges from UHMW plastic and hammered the daylights out of them and it still can take a few hours to get off. Have patience it'll take some time but there is nothing else holding it in place.... just corrosion and carbon


Posted By: frfletch
Date Posted: 21 October 2014 at 2:22pm
Don't use a screwdriver. You will end up with burrs on both the head and top of cylinder. Make a plastic wedge as Bill suggests using nylon or P.E. The best way to have removed your head would have been to remove the injector nozzle, stick a skinny screwdriver into the hole to feel the top of the piston then turn the flywheel until the piston is at the bottom. Then, use some gear oil and put it in the hole where the nozzle fits. Replace the nozzle, loosen the four bolts holding the head and cylinder about 1/4", place some towels at the bottom, and crank the engine over with the ignition. The head will blow off without force. However, now that the seal is cracked, you will likely have to continue using wedges.


Posted By: fatjohnz
Date Posted: 07 November 2014 at 8:31pm
The head made it to the machine shop and they cleaned up the valve seats and checked it out. Everything is good now -except- they found compromised structure between the exhaust port and the adjacent water jacket. He said if it was on the intake side, he would seal it with epoxy but did not believe epoxy would hold up on the exhaust side due to temp. Any suggestions? he told me to look for a replacement head body... thx, john


Posted By: frfletch
Date Posted: 08 November 2014 at 1:07am
Yes. Silicon bronze brazing to exhaust side.


Posted By: fatjohnz
Date Posted: 18 November 2014 at 3:58pm
Found another motor-head guru. Not looking good; he said welding this spot is not a option.... paper thin metal and not accessible w/ the tig.
He said a long shot would be to drill an access hole though the outer body into the water jacket to access to compromised area from behind. Bead-blast and apply epoxy from behind. Then close the access hole with a pipe tap.
Crinmar said head-bodies are no longer available from Buhk.
I've got that sinking feeling....


Posted By: Bill Layton
Date Posted: 18 November 2014 at 4:06pm
How about that fellow parting his boat out? Perhaps you could acquire the engine from him. Just an idea.


Posted By: Mike V
Date Posted: 18 November 2014 at 8:46pm
Can you send me a picture. I will check with they guys at UWP. These guys do very good work. If anyone can fix it , it would be them. I watched them repair a broken crankshaft from a ship. They are very popular with the local shops.
Mike

-------------
Sparkplug
Hull #182
NYC


Posted By: fatjohnz
Date Posted: 18 November 2014 at 10:58pm
Checked w/ MikeM earlier today and the engine and sail drive already sold.
Keith from Crinmar wants to take a look at mine so the dead head is on its way to Ontario.... Thanks for the offer MikeV but its boxed and gone.
js


Posted By: Bill Layton
Date Posted: 19 November 2014 at 8:57am
Dieter Adolphs had a complete engine/ SD for sale. PM me if you want his contact info


Posted By: fatjohnz
Date Posted: 07 December 2014 at 10:03pm
Bill , thanks for the info on the forestay.
I'm going to pull the engine and I could use any hints or tips or removal sequence that you have to make this easier.
I read a post with a trick for lifting the engine but the details were not in the post. If you would PM me or email me at fatjohnz28 at gmail dot com
much apprciated, john


Posted By: fatjohnz
Date Posted: 11 March 2015 at 11:30pm
The replacement engine has broken the bank for this season. If anyone is desperate to get rid of a racing main with a season left in it, I might be interested. js


Posted By: frfletch
Date Posted: 12 March 2015 at 1:55pm
What did you finally do in your engine replacement? Did you abandon the Bukh, or did you re-build yours?


Posted By: fatjohnz
Date Posted: 12 March 2015 at 2:05pm
I contacted Dieter as Bill suggested. Dieter had pulled the Bukh from his Laser28 and replaced it. I'm going to swap in the salvage engine(and hope it lasts for a while), and I'm going to attempt to rebuild the original motor. js


Posted By: frfletch
Date Posted: 12 March 2015 at 2:15pm
Great idea. I am a strong believer in that little engine. I did have to re-build mine a few years ago, but it was not that difficult and it runs perfectly and starts immediately every time. Of all the modern sail drive/engine combinations, I still think the Bukh is the best for our Laser.
I dream of swapping out the diesel for a 10-15 hp 4-cycle outboard power head adapted to the Bukh sail drive to try saving about 50 lbs, but don't really have the time for it and I just love the economy and reliability of the Bukh diesel.


Posted By: fatjohnz
Date Posted: 12 March 2015 at 7:40pm
{removed to continue thread}


Posted By: fatjohnz
Date Posted: 18 March 2015 at 2:49pm
Does anyone have a copy of the electrical that that is more clear than the online manuals. I can't read the colors or the component names. thx


Posted By: fatjohnz
Date Posted: 06 May 2015 at 8:42am
Can I pick your brain?
I launched the boat and fired the engine. It fired right up at high speed. I shut it down to correct a linkage problem.
I fired it again and it idled fine for a minute then I shut it down to get ready to make way.
Then it would not restart. I hit it with starter fluid multiple times and it would run for a few seconds then quit. Fuel pump is moving fuel thru the system fine and I checked that fuel can bleed out up at the injector.
So my only guess is that my injector is clogged, whatever that means. How does one clear an injector?
thanks, John



Posted By: Bill Layton
Date Posted: 06 May 2015 at 9:01am
How do you know the fuel lift pump is moving fuel thru the system? You can have fuel at the injector while the low pressure side doesn't have enough pressure. Initially anyways.

Was anything done to the fuel system or engine before this started? Why was there a linkage problem? Is the fuel shut off selonoid working correctly?

Also you shouldn't use ether on a diesel as it's too volatile and can blow the rings off the piston... use WD40 instead




Posted By: fatjohnz
Date Posted: 06 May 2015 at 10:23pm
Thanks for the PM Bill. This engine is the salvage engine I found to replace my failed motor. You were correct that there was air in the high pressure pump. I got 2 friends and bled the line at the banjo bolt near the bottom of the hard fuel line. I bled while one crew cranked the motor and the other held the compression relief to stop her from firing. After that task was done, it started right up. thank you, john


Posted By: Seawolf
Date Posted: 25 May 2015 at 11:13am
I rebuilt my engine 3 years ago due to a crack head. Luckily I manage to find the "last one" and with the help of Frank and the group I manage to learn what a wrench was and proceeded to re build an engine. Since then it has been flawless.

This weekend I decide to reacquaint myself with the engine as I took it through it's spring re-commissioning and pulled the thermostat, the trap below the thermostat to check for sediment (all clean) But then I notice some oil had dripped from the rear cap to the cylinder head. So I took that off and about 4-5 tablespoons of oil poured out.

Hmmm, I hand turned the fly wheel, no oil came spitting out of the valves. So then what? The bow of the boat had been elevated for the winter to promote good drainage out of the cockpit, could some oil seeped backwards during the winter? Last summer I had to hand crank the engine and used some oil to encourage easier starting, also did it a second time for a cold start. Could this be some residue from that?

So if I am expressing a little concern, it's I am hoping this is a no big deal and I won't have to repeat my experience of three years ago.

Any thoughts?   


Posted By: Bill Layton
Date Posted: 25 May 2015 at 11:23am
The only place to check for sediment is the bypass area... follow the cooling hose from the y connection stb side thermostat to down under the head. Air snorkle must be removed then you must remove the 2 bolts and remove that fitting. In the fitting is where sediment first starts and when it gets full can cause the head to overheat and warp. Seen it many times.

You said: But then I notice some oil had dripped from the rear cap to the cylinder head

I have no idea what you are saying? What rear cap?


Posted By: frfletch
Date Posted: 25 May 2015 at 11:56am
I assume Seawolf is speaking of the valve cover (cap?) There should not be a significant amount of oil accumulating there. Perhaps if the valve guides were worn, or valve shafts worn, then maybe, but I think that would usually translate into a smoky exhaust and some loss of oil. I have not seen oil accumulate in there. When you got this replacement head, had it been rebuilt, or was it just a working head?


Posted By: Seawolf
Date Posted: 25 May 2015 at 12:24pm
I am speaking of the value cover cap. Last summer I had no black smoke and my oil level has remain consistent, always on the top mark. I change oil once a season, which translate to 1/2 a tank of fuel. Maybe 10 hours. This was a brand new head which I purchased at Crimar.

Bill corrected me on the bypass hose, this is where I checked for no sediment.


Posted By: Bill Layton
Date Posted: 25 May 2015 at 12:36pm
I know the DV8 ME has a cap on the valve cover but I've never seen a cap on the valve cover on the DV8 LSME (saildrive version) or on a Laser 28 before. 


Posted By: frfletch
Date Posted: 25 May 2015 at 2:13pm
Aren't we speaking of the little triangular valve cover at the back of the engine held in place with three screws?


Posted By: frfletch
Date Posted: 25 May 2015 at 2:15pm
The one that gives access to the adjustments for the valve clearances? I assume this is the cover we are focused on and that oil is being found to have accumulated inside such that when the screws are removes and the seal broken that there is oil accumulated in there, which there is usually very little.


Posted By: Bill Layton
Date Posted: 25 May 2015 at 3:10pm
Yes there is only a valve cover... no cap to be found. It has 2 bolts holding it in place. There is supposed to be oil in there. 

Seawolf wrote:"I notice some oil had dripped from the rear cap to the cylinder head"

The valve cover bolts onto the cylinder head. So I'm unclear what you are saying. Is it dripping/leaking from the valve cover on the outside? externally?

The motor mounts have locknuts on them and the measurement between the top surface of the bottom nut to the flat spot on the metal mount is meant to be 25mm. If that got changed or moved the engine may now be tilted back which is the only way oil could pool in the cylinder head. If those nuts got repositioned when changing the engine it could explain excess oil in the cylinder head. But it would not hurt it.


Posted By: Seawolf
Date Posted: 25 May 2015 at 5:04pm
Thanks for the clarification, yes I am talking about the valve cover. When inspecting the motor I notice, literally a drop of oil hanging onto the bottom on the valve cover. Which got me curious so I took the cover off to find the oil which I questioned if it should be there.

The boat sat this winter with the bow high to help water drain out to the cockpit sculptors. So I reasoned that maybe some oil migrated into the valves, the area where I would check for timing. But your comment that the oil in this area is normal and as I understand it, quit worrying about it and go sailing!


Posted By: Bill Layton
Date Posted: 25 May 2015 at 6:07pm
Perhaps you should replace that valve cover gasket.. it should not drip no matter how much oil is behind it. Have a good summer!


Posted By: frfletch
Date Posted: 26 May 2015 at 10:58am
Yes. I second that. "Have a good summer"! I'm now sure you will with a rebuilt engine and no problem with the head. Oil must lubricate the rocker arms under that valve cover, so there is oil in there. Have lots of fun!


Posted By: bal149
Date Posted: 05 July 2015 at 7:58pm
Hatz-Diesel has a 722 cc vertical shaft air-cooled diesel wit 8 to 14 hp and 3000 rpm max revs in the D series - This might be something that can be adapted to replace an ailing Bukh.


Posted By: fatjohnz
Date Posted: 22 April 2020 at 8:38am
Engine rebuild fail
To recap, the original failure resulted in water in the oil and the head going to Canada for water jacket repair.
I've reassembled the engine and the test start did not go well. As the water started to fill the water jackets, an unused bolt hole on the starter side of the cylinder head started leaking water. I plugged the hole but can only assume that a water jacket in the cylinder block is leaking into a previously dry void in the block.
I continued cranking to see what else would happen. By the time water started coming out of the muffler, I also had a small amount of water/mist coming from the air intake. Still no water in the oil though.
I'm left to assume the water jacket in the head has failed again. Anything else I should investigate before pulling the head?
thx, john


Posted By: frfletch
Date Posted: 22 April 2020 at 9:07am
John,
That is a strange place for water to leak from. I have an engine block at home and I will try having a look to see what path water can take to come out from such a bolt hole. It doesn't sound likely to me, but if it is....it is.
Frank


Posted By: fatjohnz
Date Posted: 22 April 2020 at 7:18pm
Thanks Frank, I backflushed the bolt hole and it's going into the water jacket. I'll leave it plugged with a bolt.
I guess the good news is that I'm an idiot. When I installed the head I was holding up the rods with a thin piece of wire and it was still in there today when I removed the head. Luckily I have another head gasket on hand.
What I need help on is the injector. When I removed it, the cavity had liquid. It was installed with 1 thin washer.
john


Posted By: Bill Layton
Date Posted: 24 April 2020 at 2:54pm
If the injector wasn't removed before the head was sent into be repaired then they would have pressure tested the head with the injector installed.. the copper gasket seals the nozzle to the head. If it was cracked in there they wouldn't find it by pressure testing because that area would get bypassed. Before you send in the head again be sure it's completely stripped of all parts. I suspect you will also need to send in your cylinder to get repaired too. Maybe someone local to you can pressure test the head... I understand how the cylinder is built. If that bolt fixes the water leak then it's likely to be ok with that as a repair. Water can only blow out the intake if water can make it into the combustion chamber. This is typically caused by a failed headgasket, or warped deck on the head (from overheating) or a crack in the head... I've never seen a cylinder crack before, but I have seen the frost plugs blow out. Clearly this engine froze up good so you'll need a good light once the head is removed to see if you can find cracking on the cylinder deck.


Posted By: fatjohnz
Date Posted: 26 April 2020 at 3:04pm
ok. Not getting fuel out of the high pressure pump.
New head gasket and the engine is back together. I have bled the fuel system to the high pressure pump and I can get it's outlet to drip a little if I loosen the outlet fitting while I'm pumping the lift pump.
Problem is that it is not pumping when I roll the engine over. I removed the shutoff solenoid an put on a spring to pull it fully open so that should not be stopping the fuel.
I'm stumped why the high pressure is not pushing fuel.
thx, john


Posted By: Bill Layton
Date Posted: 26 April 2020 at 4:06pm
The handle on the lift pump doesn't work well enough to bleed the system. The engine must be cranked with the starter in order to bleed the system. Not sure if that is what you meant when you said " roll the engine over" I usually tie down the decompression lever so when the starter cranks it won't start and it cranks faster (no compression)... be sure when you do this to have the throttle on full "WOT"... this opens the rack fully on the injection pump so the air bleeds out much faster.


Posted By: fatjohnz
Date Posted: 26 April 2020 at 5:55pm
Thanks Bill, That got it pumping.



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