Lehr Propane outboard: horizontal tank? liquid propane?

[juggleandhope]

thanks much. sounds like a good bet then.

[Roy M]

Ditto. I just bought a Lehr 15 electric start,short shaft, which arrives Monday. I will be mounting it on an AB VS10. I'm stoked.

[HopCar]

Roy, congrats on the motor, I think you'll like it.
What are you going to use for a fuel tank?
Who did you buy the motor from?

[Roy M]

Thanks, HopCar! I hope this isn't a repeat, as I tried to answer on my smartphone. I plan on installing a mounting plate for my 20# horizontal aluminum tank, under the thwart seat. I use these tanks for my boat's cooking supply, and propane seems available more places than good, fresh, clean gasoline. Plus I'm really jazzed about it starting every time. I'm going to especially appreciate it as I get older and less willing to pull that starter cord on cold, wet mornings when I visit the Pacific Northwest. I have storage space for four 20 pound horizontal tanks in my self-draining underwing lockers.I got the motor from my supplier, Port Supply. If you want I'll send you a PM with the cost, but, out of professional courtesy, I'll refrain from doing so with mere mortals, though, I expect you would have been equally generous. But shipping across the country is a deal-breaker. After I get the boat tricked out I'll send some pics. Thanks again for all of the info you have passed along about the Lehr.

[HopCar]

Roy, you'll love the electric start but you will be surprised how easy it is to pull it over by hand. The 15 actually pulls over easier than the 9.9. The 15 has a compression release that the 9.9 doesn't have.

Did you buy the one with the internal battery or the conventional electric start?

I'm anxious to hear how you like the 15 as I'm planning to buy one for a little 14 foot plywood skiff I'm building, and building, and building, and building! When I started building it, I planned to put a 9.9 on it as there wasn't even talk of a 15. By the time I'm done, they'll have a twenty five available.

Do your horizontal tanks supply liquid or gaseous propane? Lehr is saying you need to supply liquid propane to the engine but talking to people who know, I hear that you only loose a little power at the top end on gaseous propane.

If you have any questions, don't hesitate to ask me. If I don't know the answer, I know who at Lehr to ask.

I would be interested to know what you paid for it.

[Roy M]

Thanks, again, HopCar! Mine has the internal battery (I think). I was hoping they would have produced one with an small alternator to charge a battery for nav lights and electronics. I want to use this boat for my scout vehicle, as well a for diving and ferrying supplies and crew. My fantasy is to be able to record data that I can later transfer to my electronic charts and make my own detailed explorations with the StructureScan sounder.

My tanks are horizontals designed to provide gaseous propane. I will experiment with using a standard vertical bottle on its side to see if I can detect any difference in output. I am very excited to see how the fuel economy works out. I know gasoline has greater potential energy available, I just don't know if it's enough for me to be concerned. Having only diesel and propane will make things easier, in many ways. I have a couple gas outboards in the shop if it turns out I can use them. Who knows, they may make better trade goods than transportation devices.

[HopCar]

Roy, there is an alternator in there, it's how they keep the lithium battery charged. I'm not sure if there is a way to power external loads with the internal battery,
but I know who to ask. I'll get back to you on Monday on this issue.

You seem unsure if yours has the internal battery. If it doesn't have the internal battery, you'll need an external battery that you can use to power other things as well as start the engine. A motorcycle battery should be big enough to start the engine and power some small external loads. Keep the loads light as I'm sure it's a very small alternator.

[Roy M]

HopCar, again, thanks for being on top of all of this. Yes, mine has the internal battery and charging. This is very cool. Can you ask about the output of the alternator? I would, ultimately, like to be able to charge a battery which allows me to have a 25 watt vhf, operate a very low power nav system, and run some led lights at night. Just the stuff to make the dink a true scouting vehicle, able to preceed the mother ship into strange places and record the findings. The engine is so new that the manual isn't online yet.

[Roy M]

Does anyone know what the liquid volume of a standard LP tank is? From the info at Lehr, a standard tank can deliver better than 7 hours, at wide-open throttle (WOT). I'm curious what the equivalent for a four-stroke 15 hp gasoline outboard would be. It could help in considering how much extra propane to carry when I am in the middle of nowhere.

On second thought, I may use the composite tanks for the outboard since I can easily view the volume of fuel remaining. Building a small cradle under the thwart seat won't be a problem when carrying the tank on its side, and if, as you mention, it's more efficient to provide liquid fuel, even better. Then again, if I mounted the tank upside down, it would always provide liquid fuel, until it sputters out. That's how I fill my Sodastream bottles with liquid CO2, and how I plan to transfer propane to refill my tanks in extremis.

[HopCar]

Roy, propane weighs a little more than 4 pounds per gallon. A standard 20 pound barbeque tank holds about 4-3/4 gallons of propane.

Your idea to turn a tank upside down to supply liquid propane will work. Just be sure to turn it right side up when you're not using it. When the tank is upside down, the safety valve will vent liquid propane if the tank overheats. I'm told that this is not good in a fire.

[Roy M]

I picked up a composite tank yesterday and I get the motor tomorrow, the boat will be delivered to my place on Wednesday, I got the registration yesterday, and I am searching for my 3" stencils and black rubber paint for the numbers. I probably won't get the tank mounted before I actually take it out for a spin, but I'll, at least, be able to confirm the position of the tank before doing anything more permanent.

The DMV was a little surprised when I pointed out my fuel was "other" than gas or diesel. I'm looking, now, for a good means to secure the tank and motor from those who would dearly love to have one for less than I paid. My boat has an alarm system that allows me to attach an instant alarm cable to the motor, so if I am not aboard and someone attempts to take it, well, it won't go quietly. There's an old adage in the security business that says the only way to reduce the chance of theft is to make the attempt noisy and time-consuming. With the possible threat of consequence...... That's why Fort Knox is inside a camp filled with tanks.

[ngermain]

With regards to power output with gaseous vs liquid propane...I have a 5hp and have not noticed a difference when the tank is full and warm. With a full and warm (haven't been running wide open for long) tank I tried horizontal or vertical with no noticeable power difference.

I do notice a major power loss when the tank starts to freeze. This only happened once when it was less than half full, I'd been running it for 3 hours, and it was only about 5 degrees C ambient. When the tank is cold or empty, it makes a big difference to tip it and deliver liquid.

With regards to ease of starting...When recently started (less than a day), my engine starts easily on 2nd or 3rd pull. When I disconnect the tank hose (for refilling etc) and reconnect later, it takes many pulls to start. Like 20 pulls or more. I suspect a serious air lock in the lines.

Does anyone know if there's a release on the 5hp? Something to fill up the system with propane after connecting an empty hose? I can't see anything in the manual about it.

[HopCar]

Hi ngermain, The 5 should be happy running on either liquid or gaseous propane. Only when you get to low temperatures on the small bottle that is less than half full will you see a reduction in power. When the little bottle is more than half full you're feeding liquid propane to the engine.

If you give it three pulls and it hasn't started, you've got air in the lines. It's very easy to bleed the air out but you need a very expensive tool called a paper clip.

Go here and read the Quick Start Guide. The section on priming tells you how to bleed the air. I don't know why this isn't in the owners manual.
Quick Start Guide for the 5HP outboard engine : LEHR inc.

[HopCar]

ngermain, If you're using a remote tank, you can remove the hose from the engine without getting air into the hose. If you remove the hose from the big tank, you'll need to bleed the air out or you'll pull your arm off trying to start it.

[ngermain]

Thanks HopCar! I knew there had to be something like that.

I always use a remote tank and the re-filler guys always need the hose taken off. So it's a bit of a workout to start that thing with an air-filled hose. Now I'm going to tie a paper clip in there somewhere.

Even with a 20lb remote tank, I found a big power drop when things got cold and less than half full. Shaking the tank and alternating it from horizontal to vertical was the only way I got to port. The entire lower third of the tank was covered in ice. It seemed that the propane had to at least be over a warmer, non-frozen area to get the RPMs back up. Then when that part froze over, I'd rotate the tank again.


Now the only other thing this awesome engine needs is an easy way to flush. Like a garden hose fitting built-in, somewhere up high and accessible.

I've tried flushing in a bucket supporting ropes--that's a big pain and very awkward. I've tried with a flushing attachment that fits to a garden hose. This proved tricky and unsustainable. You need to remove the flush screw on the bottom of the foot each time which is awkward and prone to dropping in the ocean. Then using some anti-seizing on the screw is a must because any water on it seems to make it seize--I broke 2 screw drivers trying to remove it the one time after I didn't apply anti-seize to it. Then I gave up flushing. Is there an easier way? Something in the quickstart guide maybe that's missing from the manual