Damaged Lehman 120?

I have a pair of Ford lehaman 120's from 1969 running my boat. They were beginning to smoke more than usual. A mechanic suggested having the injectors rebuilt. I did that and he did the removal and reinstallation on the engines. It still didn't run well. And now was hard to start. But he said all it needed was running hard for 30 minutes to "clean" them out. That did nothing and the engines were still difficult to start. Turns out the mechanic failed to set the timeing properly and it was a cog out... So now I'm worried that I damaged the engines by running them hard with the timeing so far off. Anyone know if that could have caused permanent damage? Incidently, it still smokes more than it should. So the injectors was a waste of money... Except that it eliminated that as a possible cause.

Post your concern over at boatdiesel and one of the pros there should know the answer. It would help to know if the injection was retarded or advanced. I suspect retarded is no problem, just poor combustion which should clean up by guess what, running hard for a while after setting correctly.

David

Why would the mechanic mess with the injector pump? Sounds like a moron to me... Don't pay him. I hope you got your injectors at a farm shop, not a marine store. Saves boat dollars...

All you need to do to a Lehman is change the oil and filter regularly, change the Simms oil as per the manual, set the valves each decade, likewise change the fuel filter every leap year and replace the gasket on the lift pump whenever it appears you have a head gasket leak. Then there's the other stuff like replacing the transmission and oil coolers with each new owner and making sure to carefully watch the zincs.

The injector change on the Lehman is dead easy, don't forget the new (or anneal your old ones) copper washers. Sounds like your "mechanic" isn't. Find a real mechanic and reset the injector pump, then go boating.

Lehmans smoke when cold, no worries.

If anything happens, you will likely blow cylinder number 6 and then you get to have a rebuild. The rebuilt Lehman will smoke too.

Thanks for the info... I've had the boat 12 years and I will admit I'm no mechanic. But all that you mentioned has been done and more. Still the last couple of years the smoke has no died away after warm up as it used to. And it is more smokey at start up as well. In fact, I'm embarassed to start in a whatever marine we've stopped in... Especially if there's no breeze. We leave a light blue haze over the whole place. Not to mention a sheen of oil behind us as well. It seems like ther must be something amiss. But you are right about the mechanic.. He blew a bunch of smoke up me!

Certainly as xsbank already mentioned, the injector pump should not be removed to pull and have the injectors tested. Maybe he pulled to have it checked as well? That would not usually be the case though. Anyway, I would consider locating someone better qualified, and repeat what was suppose to already be done. What you are looking for is the reason you have un burned fuel coming out of your exhaust. Two possibilities are the injectors are popping off at a lower than specified pressure (not atomizing the fuel) and low compression (if it is low it won't "fire" the cylinder very well). Since the injectors have possibly been checked already, I would hire the new guy to check cylinder compression first when he arrives. I'm sure it should be checked with the engine hot, so make sure he runs them first. The injectors will have to come out to insert the compression tester, so this should all go hand in hand. As suggested earlier, check on boatdiesel to see what the minimum compression should be, then you can tell your mechanic what he is looking for.
You might also want to check your local Ford tractor dealership for a possible mechanic, if there are not a lot of choices. Good luck!


1983 Present 42 Sundeck
Twin Lehman 135's

Bermudas2 said:

Thanks for the info... I've had the boat 12 years and I will admit I'm no mechanic. But all that you mentioned has been done and more. Still the last couple of years the smoke has no died away after warm up as it used to. And it is more smokey at start up as well. In fact, I'm embarassed to start in a whatever marine we've stopped in... Especially if there's no breeze. We leave a light blue haze over the whole place. Not to mention a sheen of oil behind us as well. It seems like ther must be something amiss. But you are right about the mechanic.. He blew a bunch of smoke up me!

Click to expand...

Are you sure somebody didn't sneak in and replace your Lehman with a old Volvo..
It sounds just like mine at start up..look on the positive side..your helping to reduce the mosquito population!

Hollywood

Get a new mechanic. Does the smoke mostly clear up once the engines warm up? If so the get block heaters if the smoke really bothers you.

Bermudas2 said:

I have a pair of Ford lehaman 120's from 1969 running my boat. They were beginning to smoke more than usual. A mechanic suggested having the injectors rebuilt. I did that and he did the removal and reinstallation on the engines. It still didn't run well. And now was hard to start. But he said all it needed was running hard for 30 minutes to "clean" them out. That did nothing and the engines were still difficult to start. Turns out the mechanic failed to set the timeing properly and it was a cog out... So now I'm worried that I damaged the engines by running them hard with the timeing so far off. Anyone know if that could have caused permanent damage? Incidently, it still smokes more than it should. So the injectors was a waste of money... Except that it eliminated that as a possible cause.

Click to expand...

Just curious how many hours the engine has. My father's 1977 Lehman smokes quite a bit even after warmed up. It's been doing that for years, he's got 5,000 hours on it. My 1983 Lehman smokes, then virtually stops after reaching temp, I have 1500 hours. I am concerned with the sheen.... have you had your oil tested? That's where I would start..... it's inexpensive and can help rule some things out. Good luck, let us know what you find out.

I`ll throw out a few thoughts
I read it`s blue smoke. Are they using oil? They are 45 years old.
Both exhibiting the same change at the same time seems a big coincidence.
Did you do anything that might have glazed the bores on both? Like long unloaded idling.
Any change of fuel supply about the time it started?

I did have the oil checked when I purchased the boat in 2002... It was fine. As to the engine hours I have no reliable information. When I purchased it both Hobbs meters were broken. One read 1200 hours and the other 1600 hours. Since then I've put 2000 hours on the engines. And it is a good point that both engines are showing the same problems. It was the end of the summer before last that the engines began to continue smoking after warm up along with more smoke at start up. Also, the oil sheen that is now evident all the time became much more obvious... although it's only visible when we're anchoring or docking. There has never been a period of running unloaded during my ownership. Although that makes me think they are possibly running too cool in general.. One runs at about 170 f. The other at about 180. Could that cause the problems?

Thanks to all those who have replied.. I have a number of useful ideas to follow up on. And the first will be to find a decent mechanic.

A new mechanic will give a fresh assessment.
Another thought. Did you change the brand or weight of oil when symptoms appeared?
You can raise a query with Brian Smith of American Diesel, the "successors" to Lehman (Bob Smith was Lehman VP, he wrote the forward to the FL Manual).

A bit of an oil sheen is no big deal, could be unburned diesel, could be lube oil getting past worn rings.

Either way forgetaboutit.

The amount of fuel will not add up to a gallon a season , and if the oil consumption gets up to a quart in 10 hours (500 miles car equivelant ,) its still cheaper to just by oil.

Have someone that is familiar with your engine to time it , and enjoy.

FF said:

A bit of an oil sheen is no big deal, could be unburned diesel, could be lube oil getting past worn rings.

Either way forgetaboutit.

The amount of fuel will not add up to a gallon a season , and if the oil consumption gets up to a quart in 10 hours (500 miles car equivelant ,) its still cheaper to just by oil.

Have someone that is familiar with your engine to time it , and enjoy.

Click to expand...

Sounds like mine

I'm up to aobut a qourt of oil every 50 hours.

I thought the oil sheen was telling me all was normal and as for the smoke, I thought it's purpose is to remind me to close the salon door

I will (may) adjust the valves this winter. and I just changed the oil, so I'm good til spring.

A beautiful engine. i think I'm in love

I tend to agree with Fred. But here are a couple of suggestions:

Blue smoke is an indication of oil, not fuel. Does it use oil? Maybe the oil level is too high and the crankshaft is whipping it up and out. Try running for a while with a quart less.

Sometimes a grade change can have a dramatic affect on oil consumption. Try a single grade, either 30 weight or 40 in warm climates and see if that has an effect.

Finally, rather than a compression test, try a simple blowby test. Open the oil filler cap while under way at moderate rpms. Feel for exhaust pulses. Heavy flow that blows your hand back is an indication of worn rings. If so it will take a full rebuild to fix, so forgetaboutit!!

David

FF said:

A bit of an oil sheen is no big deal, could be unburned diesel, could be lube oil getting past worn rings.

Either way forgetaboutit.

The amount of fuel will not add up to a gallon a season , and if the oil consumption gets up to a quart in 10 hours (500 miles car equivelant ,) its still cheaper to just by oil.

Have someone that is familiar with your engine to time it , and enjoy.

Click to expand...

Have you done the dreaded dipstick re-mark? How much oil do you put in at oil change time? $5 says your dipstick has never been re-calibrated and you put too much in. Think level engine in combine, then look how your engine tilts back for your boat install. They never gave you a "marine" dipstick as there was no such thing. Too much oil gives you more blow-by and more sheen and higher risk for leaks until it can get rid of the excess to the level it likes. Measure the oil. Use antique Delo oil, it likes that best. The new injectors will lower the amount of sheen on the water but it's always there.
Try and warm them up in gear. They like that too and the wash hides the sheen 8^)

Please don't start an oil argument!

Xsbank said:

Have you done the dreaded dipstick re-mark? How much oil do you put in at oil change time? $5 says your dipstick has never been re-calibrated and you put too much in. Think level engine in combine, then look how your engine tilts back for your boat install. They never gave you a "marine" dipstick as there was no such thing.

Click to expand...

The service manual for our Yanmar states it takes between 2.5 and 7 litres, and the low/high marks on the dipstick are over an inch apart. Seems happy at around 4 litres where the PO made a mark on the dipstick.

Sure would help if manufacturers printed a graph showing the amount of oil needed at what degree of incline.

Bermudas2 said:

Not to mention a sheen of oil behind us as well.

Click to expand...

The sheen on the water behind a Lehman after startup is not oil as many people tend to believe, it's unburned fuel. This is the nature of the beast with old generation engines like the Fords, and does not indicate there is a problem. The reason is that until the cylinders come up to temperature, some of the fuel injected into the cylinder is not burned, so it goes out with the exhaust and forms a sheen on the water behind the boat. This is more noticeable in the winter than in the summer because the engine(s) will be even colder and it will take longer for the cylinders to come up to temperature.

The sheen should go away once the cylinders get up into the proper temperature range and all the fuel being injected is being burned.

Oil in the cylinders, as from leakdown past the valve stem seals after the engines are shut off, goes out the exhaust as blue smoke, which is why the Fords smoke at startup. They should clean up pretty well within a few minutes after startup. If they continue to smoke (blue), then there is a problem that is allowing lube oil to get into one or more cylinders This is most commonly a worn valve stem or guide, or shot valve stem seals, or all of the above.

A good friend who was the head of the engineering department at Northern Lights/Lugger (formerly Alaska Diesel Electric) for decades until his retirement the other year, told us when we bought our boat back in 1998 that eliminating the unburned-fuel-when-cold problem (because of the pollution) was one of the hardest things the engine designers had to figure out how to do. A I said, it's the nature of the beast.

Thanks to everyone who took thier time to offer an opinion or advice. I was mostly concerned about running the engines hard with the timing out by almost a cog. It seems that the conesus is that damage from that is unlikely. So I can relax about that. But I cannot, as has been suggested just forget about the excessive smoke and oil sheen. Both of those are significant, new this last year and remain after the engine is warmed up.

If it is a still day at an anchorge or marina I am embarassed to start my engines becasue there is now enough smoke that it will just settle in and hang over the area. Enen when arriving after running for hours the engiones are smoking and putting out an oil slick. The intensity is new, just starting the past summer... So something is wrong and I need to get to the bottom of it.

I havce calibrated my dip sticks at the 3 gallon mark. And I always use Delo 400 SAE30. I change the engine and injector oil regularly.

The smoke is grey. It looks almost like steam. And the unburned fuel sheen is what it is.. I don't think it's oil.

Unfortunatly, the mechanic who took care of my engines for many years retired a couple of years ago and I have not been able to find someone to replace him. My latest attemps has just cost me a bundle (for rebuilding the injectors & pump) and did nothing for the problem. And not only is the smoke and unburned fuel sheen still present... and actually worse. Now the engines clack and knock more than they did (I was concerned that was caused by running them hard with the timing off). And one of them tends to be seeking (RPM) all the time. Since the mecahanic who removed and replaced the injectors failed to set the timing I suspect he never checked the valves when the cover was off either. And who knows what else he failed to do... or did incorrectly. I have a big problem with that outfit. But at least the engines have not been damaged by my following their service managers insistance that I run them hard... That was a big concern for me.

Again, thanks to everyone for the ideas and suggestions. I will try the oil cap removal test. And continue to look for a decent mechanic in Seattle... Anyone have one he'd like to suggest?

Lots of good ones in Seattle. Call Ken Bowles at that big Grand Banks charter place (senior moment), he is very friendly and will recommend some good ones - he had one of his rebuilt very successfully by a local guy.

You should be at Rendezvous in Roche Harbour Sunday morning when 120 GBs or approximately 200 Lehmans all start up at once!

Bermudas2 said:

The smoke is grey. It looks almost like steam. And the unburned fuel sheen is what it is.. I don't think it's oil.

Click to expand...

That`s new information. Nigel Calder (Marine Diesel Engines) says : with white smoke, check if it is vapor or atomized unburnt fuel, briefly put a hand over the exhaust and sniff it. He says persisting unburnt fuel after warm up can mean a defective injector.(Isn`t that what the guy "fixed"?)
I`d expect water vapor to dissipate easily, like a car with a blown head gasket, not to pollute the marina.
[Reference: Nigel Calder - Marine Diesel Engines, 3rd Edn,pp 116-117.]

We use Tri-County Diesel in Bellingham, proprietor Mike. You also might call Bob or Brian Smith at American Diesel back east. While diagnosing an engine problem is nigh on impossible over the phone, they may be able to hazard some pretty good guesses at potential causes, and they may have some folks in the Puget Sound area to recommend.

Engines & Generators : Harbor Marine

These guys are very helpful. Good luck.

Ah... More very useful information! That sounds like something I might try... The heavier oil that is. I actually happen to have the boat for sale already. It's been on the market for a while now. But being wooden it will only appeal to a few buyers.

I had hoped the new injectors would help with the problem as I'm afraid that the smoking may put off a buyer. Also I did go to the diesel engine blog you mentioned and a mechanic in Nanaimo answered with some good suggestions. As we are now heading south and just coming up on that city I have arranged to have him look at them as we pass through. I'm hoping he can put things right. It may be that just setting everything properly (valves, timing, injectors, etc.) may help and get the engines back to the standard Lehman smoking scenariio. I think the last diesel outfit I used sent out a mechanic who didn't have a clue and so who knows how he left things! Anyway I'm going to be there tomorrow and see what he says...

Thanks for the ideas, though. I may well try the oil. I'll let you know the results if I do....

BruceK said:

That`s new information. Nigel Calder (Marine Diesel Engines) says : with white smoke, check if it is vapor or atomized unburnt fuel, briefly put a hand over the exhaust and sniff it. He says persisting unburnt fuel after warm up can mean a defective injector.(Isn`t that what the guy "fixed"?)
I`d expect water vapor to dissipate easily, like a car with a blown head gasket, not to pollute the marina.
[Reference: Nigel Calder - Marine Diesel Engines, 3rd Edn,pp 116-117.]

Click to expand...

You can have both a sheen, steam and no white fuel smoke.

You don't always get white fuel smoke and a sheen. In fact most of the times I've seen a sheen there is no smoke because if you're getting a sheen it's due to dumping raw fuel out the exhaust. Not just running rich.

That makes a lot of sense, becasue the smoke struck me as steam-like as it disappears rather quickly... as if it was evaporating... This is under way I'm talking about, with fully warmed up engines. It could well be unburned fuel vapor and the slick looks like fuel to me as it has that lite look about it... different from an engine oil slick... At least that's my sense when I look at it in the water... It looks the same as spilled fuel (Don't ask me how I know what that looks like!)
Anyway, I'm going to do the sniff test and see. If it is some sort of injector problem I wouldn't be surprised... And if it is, heads will surely roll... Not to mention a refund.

Anyway, thanks.... I think I'll get that book... sounds like a whole diesel forum in one handy place... Besides, I've heard it praised by a couple of other people...

The process of elimination

Well, I took someone's advice on this forum and posted my concerns on boat diesel.com. There I had a reply from a mechanic in Nananimo, BC. He had some great advice and obviously knew his way around these old engines. As luck would have it, we were then two days north of Nanaiamo, heading south. So I emailed his shop and they shifted their schedule to allow Rob the day to go over my engines. He went over them in detail, checking everything that might be the casue of excessive smoke. He set the timing, checked the valves and pressure tested the engines. The result was that nothing helped and the smoke remained. His view is that they are just old and wearing out... Need the dreaded rebuild. So, now I know the situation.

It was important for me to know everyhting has been properly checked and all possible smoke casues have been elimited... leaving only worn/stuck rings or something along those lines.

So, the stop was well worth it. Rob and his service manage we both outstanding... one with the work on the engines, the other with adjusting his service schedule to accomodate mine. (Stone's marina/Nanaimo Yacht Services). Very professional and thorough... I just wish they were in Seattle.

Thanks to everyone here who spent thier time offering infomation and advice. It was all useful and helped in one way or another...

Good to hear.

In ten years let us know how the rebuild goes a long.

Glad Stones worked for you, that's where I get hauled...

Took the boat into a recommended diesel outfit in Seattle for a second opinion... They checked them over quite thoroughly. They couldn't find anything wrong... Saying that Lehman's will always smoke some, even when warm... That's just the nature of these engines. They were, after all, built to lower tolerances than modern engines. They acknowledge the engines are getting up there in years, but that alone is not the criteria they say. Apparently they have seen other, older Lehmans' with a lots of hours running just fine. In the end they basically suggested I was being too fussy and overreacting....! I think they looked around the boat and decided I was just a perfectionist! Perhaps they are right... They did suggest I use 40 wt oil based on the running temperature in the engine room, not the outside air temperature...