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First problem with Lehr outboard?

Nov 9, 2012
Oday 192 Lake Nockamixon
I've been reading about Lehr propane outboards, and the folks who have bought them all seem pretty happy with them... except one guy on my dock.

Last night I heard him firing up 2.5hp on his Day Sailer a few times, and it was revving pretty fast. Then I saw him heading out, at well above 1/2 throttle, maybe WOT. (I dunno how fast those 2.5hp go...)

When he came back in, I asked if he was having engine trouble. And, he was. It seems his throttle is stuck open. He said he traced the cable all the way back to the "carb" and the cable was moving, so something must be stuck in the "carb." (I am assuming it's not a carburetor as we know it, what with the propane and all...)

He was going to call Lehr today to talk to them, before he starts ripping things open.

May 11, 2005
Seidelman S37 Slidell, La.
I know nothing

About these motors, except! Any time you get anything mechanical that is a small production item, with very few dealers, service is always a nightmare. And the same with parts. No matter how well designed and engineered. No matter how good the quality control. Service and parts are always hard to come by.
Nov 6, 2006
Hunter 34 Mandeville Louisiana
The engine that Lehr uses is a "PARSUN" engine made in China..
The engines look to be well built, but i don't have any experience with them. I don't think that they have a big service base here in the US but as I understand it, Lehr will be able to get parts and service them.. I wouldn't buy one unless I were a pretty good small engine mechanic. The propane conversion that Lehr does to the gasoline Parsun involves a slide throttle (like a motorcycle) and a "demand" regulator supplying a flow sensor and gas distributor (in place of a gasoline carburetor). When ya open the throttle, the regulator feels more demand and supplies more propane. Sounds like his regulator is not feeling the correct fuel signal.. could be a stuck throttle piston or a sensor tube disconnected or a faulty or dirty regulator.. or even leaks in the fuel supply hoses/tubing inside the cowl. It will be interesting to hear what Lehr has to say.
Nov 9, 2012
Oday 192 Lake Nockamixon
Kloudie, that's interesting about Parsun. I heard from a dealer at the Atlantic City Boat Show this spring that they were Yamaha motors. And I heard elsewhere that they were Tohatsu. Hopefully the Parsun manufacturing has good quality control - sometimes Chinese companies do not.

I wonder if I'll see the guy this weekend to find out what Lehr said...

Oct 20, 2013
Pearson Ensign San Diego
This may be a little late for this post, I look after three of the Lehr 5 Hp motors . They have turned out to be very reliable. They did have a few teething problems when they were new, and one of them was the sticking throttle. This was caused by the guys in the factory screwing the cap down a little too tight on the slide retainer on the slide carburetor. Backing this off a 10th of a turn makes this problem go away. Later we also discovered an additional slide sticking problem caused by mis- use . One engine got drowned by a following wave. 2 days later the throttle stuck. On dis-assembling the carb slide, corrosion products from salt water, white fuzz and salt crystals were found gumming up the works.
Cleaning this out restored perfect working order. the problems with water in the gasoline and corrosion products in the carbs are a thing of the past . These motors start first time every time.
Mar 20, 2004
Hunter 356 and 216 Portland, ME
We've found Lehr support to be very helpful - you have to burp the 2.5 carb by pushing a paperclip into the small hole on the carb ( on the round plate) when you first set it up. Based on the parts we've seen, I'd guess that parsun makes to small yamahas, too.
Oct 20, 2013
Pearson Ensign San Diego
That is the rich start, if you have to do this in warm weather , the mixture is set a bit too lean. Or you have a new hose for an external tank which has air in it.


May 23, 2011
Nauticat 32 Portland
I purchased a Lehr 2.5 hp outboard in Feburary of 2013 to replace a Honda 5 hp outboard on my inflatable dinghy. I was tired of smelling gasoline fumes and the Honda was larger than I needed for our rollup dinghy. Initiallyl, I was quite enthusiastic about the Lehr motor. It solved the gasoline fumes problem, always started on the first or second pull and was quite reliable. I really like the idea of eliminating one of the fuels from my boat, and I already use the propane camping cylinders for my barbeque grill. I found that I had to replace the propane cylinders more than I had expected, but if I ran the motor at a low speed, I could get about two hours of operation from one camping cylinder.

There were minor issues that tempered my enthusiasm a bit. First, Lehr recommends “disconnecting the fuel” after every use. It was not clear to me if that meant removing the small cylinders or (if used) disconnecting a larger external tank. I never used an external tank and left the cylinder in place until empty, partly because I found switching cylinders to be painful to my fingers due to the short hose in the engine and the limited clearance it affords to hold the threaded gas fitting while installing a new cylinder.

Another issue (perhaps not unique to Lehr,) is that in salt water, they recommend running fresh water through the engine after every use. This is easier said than done. There is no fitting to attach a garden hose or other water source to introduce cooling water to the engine. And the usual “ear muff like” flushing accessories won’t seal around the water inlet due to protective fins and the small size of the shaft housing. So that left me having to use several gallons of water in a plastic trash can held in place by a strap while I ran the engine attached to the rail of my sailboat. I don’t know what the requirements for other outboards is, but I ran my Honda for entire seasons without rinsing until the end of the season and never had any problems.

All in all, I was very happy with the Lehr outboard for the first season of use. I used it several times per week for the entire 4 months I lived on our sailboat in the Pacific Northwest, and apart from the minor issues above, had no complaints. THIS SEASON, however, is a completely different story,

After being properly put away for storage in the winter, I first attempted to fire up the Lehr on a trip from Washington to Barkely Sound on Vancouver Island. The instant I attached a gas cylinder, I heard and smelled propane shooting out from inside the engine in the vicinity of the fitting for the external tank hose. At the time, I was far from any authorized service location, but desperate to get it running, so I contacted Lehr and got a timely response to my inquiry about repairing the leak with O rings purchased from a hardware store. I was able to replace the seals of the internal fuel line with O rings and new gas compatible Teflon tape, and there were no more leaks. The motor ran fine for about a week.

Then, the motor started becoming difficult to start and was not running well. Finally, when it would not start at all, I tried replacing the spark plug. I was able to start it and it ran badly for about an hour. At the point it died again, and I noticed that the oil had turned white, looking at the oil level inspection glass. At this point, I contacted Lehr again and began the (arduous) process of finding somebody authorized to work on it. There are plenty of stores which sell the Lehr motors, but apparently far fewer that actually service them. Finally, I was able to get the motor to Harbour Chandlers in Nanaimo and after a brief diagnosis (mainly to be sure I hadn’t dropped it in the water, I suspect,) they ordered new seals and a head gasket. Lehr was able to get them the parts in a timely fashion, only three days including customs, as the parts were shipped from California. The mechanic replaced all relevant seals and the head gasket and (four weeks after the problem arose) I now have a working motor, which once again starts on the first or second pull and seems to run just fine. There was no cost to me, apart from the moorage fees, taxis and time lost on our trip. The engine comes with a three year parts and labor warranty, and they seem to honor that without a problem.

I understand that a Chinese company (Parsun) manufactures this motor for Lehr, and also very similar motors (except for the fuel system) for Yamaha, Tohatsu and other companies. That gives me some confidence that the reliability of everything except the fuel system should be similar to other small outboards on the market, despite my unfortunate experience. I am keeping my fingers crossed that this is the last problem I have with this motor and that I get a few good seasons of use from it. My serial number ends in 00090, so I think I have a very early motor. The manufacturing date is shown inside the engine as May 2012, even though I bought it in February 2013. Hopefully, the new motors are less prone to problems.
Oct 20, 2013
Pearson Ensign San Diego
I have 3 of the 5hp motors. we use a 1 gallon tank with ours, leave the gas lines connected ,and turn the gas off at the tank. In order to flush our motors we use a flush bag, ( http://yachtsee.com/flushingbag.htm), this has a hose attachment at the bottom and a flap at the top that fits around the outboard motor bracket. Just slide it under the motor shaft, secure it and turn on the water. When the water starts flowing out of the bag, start the motor and run for ten min's or so. One problem one of our early Lehr motors had was hard starting, this turned out to be an overly rich mixture. the mixture is set by turning a tapered needle in, or out , on the slide of the carburetor . In this particular case the screw thread was sloppy, it was fixed by putting a drop of Loctite on the thread and setting the mixture before the Loctite cured. Lehr has stood by their product, and supplied parts in a timely manner, sometimes for free. Here is a list of problems I have had, not all of them the fault of the motors which are now pushing 450 to 500 hours. :
Rich mixture detailed above, bad kill switch, wax build up on tapered needle, Starter cord broke, (one instance). salt crystals built up in carb slide, ( splashing water on motor)
steering friction screw jamming from salt corrosion.
All in all not bad performance , it sounds like from your description that you had a leaking head gasket. I must point out that prior to buying the propane motors , I was spending 2 to 300 dollars per month on carb parts for gasoline motors.
Oct 20, 2013
Pearson Ensign San Diego
I have just hit my first problem with the Lehr motors that relates to fuel contamination of the propane. I am working with Lehr and my propane supplier to resolve this and will post more info as I update the problem. This applies to people using a remote tank rather than the small on board cylinders which are filled with a higher quality gas.
Essentially the motor draws vapor from the tank. The propane supplier provides the propane to you as a liquid, when you run the motor the propane boils off, leaving whatever was dissolved in the propane behind. It turns out Propane is a pretty good solvent and will dissolve oil , grease and plasticizers from pipes and hoses and whatever else it goes through on its way to you.
The problem manifested itself as a motor ( remember I have 3 of these) that would start and run for one minute then quit. Thinking the burst hose feature had tripped on the tank, I shut the valve and removed the line, as the pressure dropped as I unscrewed the hose fitting, a foam ,like spray grease came out of the fitting, this then settled down to a thick light brown oil. Looking into the opening of the valve It appeared to be plugged with what appeared to be wax polish. this I was able to scoop out with a screwdriver. I have taken the hose and the tank to my propane supply house, they were flaring the tank off so it could be inspected. They also cut the ends off the hose and split it lengthwise finding clumps of wax in the hose.
I have now ordered inline propane gas filters ( IMPCO A3-514 ) I am also going to look at the Mr. heater F273699 filter But I am going to have to check with Lehr first to see if that one is acceptable. Again this problem is not a fault with the motor, but a problem with a batch of bad gas. The RV folks also have this same problem and I found quite a bit of info on the problem on their sites.
Maint chief.
Aug 4, 2018
Pearson Yachts 39-II Punta Gorda, FL
I own a LEHR LP15S outboard, i.e. 15 HP Propane fueled, std length, manual pull start motor. Bought it April, 2015, so my 3-year warranty expired several months ago. Until this month my only failure with this outstanding engine was a broken shift lever - my fault as I tilted the motor up shifted into forward with the thwart board seat of my Achilles drifted pretty far aft. Lehr service replaced that within a few days - no problem.

But last week the carburetor blew a diaphragm, so propane leaked audibly and totally as soon as the tank supply was opened [soap bubble trace isolated it]. After getting the carb out [easy] and buying a Tamper-Proof Torx T-20 key at Home Depot I opened the carb and inspected the 3 diaphragms. The primary regulating one at the gas supply was the failed one. Although LEHR does not provide parts for the carb below assembly level, just the entire carb assy at over $160 each, the customer service Mgr in NC immediately routed my issue to the LEHR engineers in CA just to see if they might have a diaphragm on hand. They did and sent me one overnight for only the costs of shipping. Almost incredible level of Customer Support. That's my real brag. These folks are exceptional - outstanding. But there's more:

Just to be certain which of the 3 diaphragms I needed I sent the engineer a photo of the failed part. Not only did that nail down the part number but also he looked very carefully and noted deposits of some greasy/oily residue on the part and in the carb, and alerted me to that possibly of that being the cause of failure of the part, of the carburetor - contaminants in the propane supply/tank as noted earlier by Maint. Chief's post. To be continued...
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Aug 4, 2018
Pearson Yachts 39-II Punta Gorda, FL
Continuing from 5 min ago: Further research showed commercial propane supplies are commonly contaminated with many hydrocarbons and users like us in Marine but also in RVs , propane fork lifts, and just plain gas grill users have seen this issue of contamination and damage to regulators, etc. Here is a link to a very clear and thorough tech paper on this issue which names the top five representative contaminant culprits in commercial propane supplies: http://www.adeptscience.net/Presentations/061020 gtc paper-decont.pdf
The Nitrile rubber used by LEHR for its carburetor parts, and about every mfr who designs parts for propane, is susceptible to at least one of the common contaminants identified in the paper: Benzyl Butyl Phthalate or Butyl Benzyl Phthalate. This is a plasticizer that is also used to manufacture Nitrile rubber itself, and so can be expected to weaken if not dissolve it over time - just as warned, generally, by the LEHR engineer. I am working with LEHR Engineering on this, suggesting alternate elastomers like Parker's HiFluor fluorcarbon FKM for their carb parts so that even in the presence of these contaminants in their chosen fuel supply their product will be resistant to such failures. Meanwhile, it does seem sensible to take a look at coalescing or other filters that might be placed inline between the propane tank and the engine to try to remove these oils/greases/contaminants. I'm asking if anyone has employed such filters, at what cost, and what results you may have gotten before and after?


Mar 16, 2010
Beneteau 411 Oceanis Annapolis
As noted earlier, MrHeater recommendations use of their in-line gas filter for just this contamination issue. Never had a problem as a result. Still on the original filter, 8 years and 100 lbs of LPG later
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Aug 4, 2018
Pearson Yachts 39-II Punta Gorda, FL
Good to hear, Gunni. Thanks for your post. I just ordered one of the Big Buddy Heaters #F273699 filters @ only $12.79 on Amazon Prime. It looks like its threaded ports are all set for direct insertion between my LEHR supply port and its supply hose. The IMPCO A3-514 filter also mentioned by MaintChief has 3/8 SAE Male flare threads apparently all set for fuel tubing fitting to Yale/Hyster forklift engines and would have to be adapted to fit in the LEHR setup.
Aug 4, 2018
Pearson Yachts 39-II Punta Gorda, FL
After repairing the carb as described above then installing the propane filter recommended in this forum I found I'd experienced my second LEHR LP15S engine failure. The plastic latch that enforces transmission-in-neutral before allowing pull start broke in the way of preventing the rope pull more than an inch or two. Removing the broken part allowed easy starting again.

While waiting for LEHR service to quote the replacement part & recalling kloudie1's post here about the LEHR engines being fuel modified Parsun products I did some web searching by description. I was able to identify the exact same custom molded plastic part online using illustrated parts breakdown drawings for Yamaha, Tohatsu, Parsun themselves, and Mercury 15HP outboards though they called the part "stopper", "starter lock", and "arrester" and all had their own part numbers. LEHR got back to me with their quote for the "Stopper OB323.1-182" for a whopping $26.20 ! I thanked them then ordered the Mercury equivalent 852788 1 from Buster Marine, via Walmart online, for only $5.22, free shipping! Anyway, it's good to know that so many other engine mfrs stock parts, other than the fuel system, of course, that fit the LEHRs.
Jan 18, 2016
Catalina 387 Dana Point
Ahhh... Story time...

Recently took a short sail to Newport Beach for the weekend - was on a mooring so we brought the dinghy to cruise around the harbor. 'Cause that's the sport at Newport. A few weeks earlier my Lehr 2.5 blew it's fuel line at the isthmus's dinghy dock. Yup, a pound of propane blown all over the place. I got a replacement (the 3rd one!) from Lehr and fixed it the day before heading to Newport.

Newport day1: Dinghy about .25 miles to get a bag of ice for cocktail hour. Dink back. Have great G&Ts and enjoy watching duffy boats go by all evening showing questionable sobriety and seamanship. The boats are nice and quiet, the folks inside notsomuch. :)

Newport day2: Coffee. Watch the boats go by. Paddleboard yoga right next to my boat - that was interesting. Then "Let's do a Harbor Tour!" ok, I'm good for that. So we hop in the dink. Less than 5 min later there's a sheen behind the dink and it smells like oil. Yup, spitting a buttload of oil out the air filter. Row to the dingy dock. Ask some folks in a Beneteau 38 if they could give me some paper towels to limit how much oil ended up in the harbor. They obliged and I stuffed the bottom of the engine. I hear "you've been fixing that dang engine since you got it... it's over.." I agree. Thus the mile long walk to West Marine. A brand new merc 3.5 and a gas can were purchased. Unboxed the motor and left West the box, threw it into the back of a Lyft, had the driver get me to where I could buy a gallon of gas, and back to the dink. Got the new motor mounted, oiled, gassed, and it was just fine.

So I got a parts Lehr 2.5 if anybody needs one. I'd guess valve guides not rings as it was running while spitting oil. But I'm not going to fix it. Over my 5 years of ownership I've replaced 3 fuel lines, the 'carb' (the diaphragm blew out), and the shut-off switch. Not tooo bad, but it's been a pita - I'd just as soon rebuild the carb on a gas engine. The merc 3.5 is noticeably quieter and as expected more power. But it's definitely harder to start. Once it was primed, the Lehr was the easiest outboard in the world to start cold or warm. One maybe two pulls and it was going. Overall? IMHO, Great idea, mediocre implementation.
Mar 8, 2012
Morgan OutIsland 30 Perth Amboy
I'm having trouble locating a parts list anywhere on the web for my 2.5hp Lehr. Is anyone here aware of one? The part I need is a throttle cable and I thought (since the Lehr is mostly a Yamaha) that I would just pop down to the local Yamaha dealer and get one. No such dice. As they say. The part (being a propane-specific part) is definitely not one that's common to Yamaha. I tried 5 different phone numbers for Lehr and they all failed today. Right now I'm anchored in Grenada and it's a long windy row ashore.
Aug 4, 2018
Pearson Yachts 39-II Punta Gorda, FL
The service manual is located here:
On pg 72 it shows the part you asked about is OB072.6-025 [first character is letter "O", others are zeros], though back on pg 28 or so it also shows there's a throttle cable cap and slide assy that may be carburetor parts and may be what you also need?.

Lehr Customer Support : customersupport@golehr.com .

I tried calling for you, but also found their phone numbers inop. as well as their parts store, and their dealer locator. It looks like some serious website problems, maybe company problems, maybe just the Memorial Day holiday?

Last August I was getting good responses from :
Jay Mangano
LEHR Support Manager
424-250-6816 Direct
866-941-5347 Company
323-370-6811 Fax

He also mentioned :"Please contact LEHR's main office @ 704-827-9368 and ask for Angel."
And put me in contact with a very helpful tech, also in L.A:
David Kostka , david@golehr.com

You might also want to try West Marine customer service at Phone: 1 (800) 262-8464 to see if they at least know if Lehr Marine is still in business.
Dec 28, 2015
Laser, Hunter H30 Cherubini Tacoma
I bought my 2.5hp used for a song (325) last year and have used it maybe 2 1lb bottles. We noticed a propane smell/leak a couple weeks ago. Expecting the wort to took it home to work on it. I found the bango bolt that connects the regulator the the carb leaking. A little tightening up and all was well. I don’t think I would buy one new though. For the price, they have flimsy cowlings and obviously cheap materials.