1958 Evinrude Lark 35 Water Pump ?'s

[warstoryz]

Hello to everyone. Please excuse my lack of knowledge about outboard motors, but up until my son brought home an old Lone Star with a 58 Evinrude 35 HP Lark engine, I had limited my 2 cycle work to chain saws and mowers. To get to the point, can anyone help me to understand why this old engine will not pump water. I relaced the seals and the impeller, submerged the lower unit in a big barrel of water and put the motor in gear. The prop turns as it should , but all i am getting out of the water hole is comparable to a heavy drizzling rain, not a stream of water. If I run it long enough steam also starts to come out of the hole. This looked liked a pretty simple internal system, but now it has me stumped. Any help would be very much appreciated. John

 

[R.Johnson]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

You probably need the whole water pump assembly. Tahe off the thermostat cover on top of the cylinder head, and see how much water flow you have there.

 

[jameswilson95]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

John, I have a 69 40 hp evinrude and I have changed just about everything in the gearcase. I also have water coming out of the hole along with exhaust(steam) which is normal for my motor. It doesnt seem like much (like a heavy rain)but as you increase the rpms it should also increase the amount of water being pumped. Something else you might check to see if your water intake has a screen which might be partially blocked with something. Just trying to be helpful. Some old fart on this forum probably knows lots about your particular motor...you just need to be patient and keep asking you question. Eventually you'll get the answer you're after. cheers! Jim

 

[rogerwa]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

I'm not sure how many of the old motors had telltale streams like the new one do, if any. The drizzle or spray may be absolutely normal. If your powerhead remains cool, I think it is working fine. You should be able to touch the power head for a few seconds. If you can't it is running too hot.<br /><br />This may be the exhaust relief holes you are looking at in which case all you get is a drizzle and not a steady stream.<br /><br />If you running hot you've got a cooling problem. If not then you should be fine..<br /><br />After reading your post again I think it is working as designed..

 

[BoatBuoy]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

John,<br /> As has been said, you may be OK. But then you may not. Not knowing the history, replacing the water pump impeller is strongly advised by most of the veterans. Not a complicated job, but you will need a manual. You can probably find one at your library, a Clymer's or Seloc. Not as good as OMC reprint, but borrowing from a library is cheap.<br /><br />Parts are available from your local johnson/evinrude dealer or right here at iboats.

 

[warstoryz]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

Thanks to all for the help. I'll wait until the manual arrives and let you know if I get out on the water and back or if I end up floating around somewhere looking to hitch a ride. <smile>

 

[cheburashka]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

If it's any help, my '57 Lark also drizzles at idle. Once you bring it up to speed the flow increases.<br /><br />One other thing bears mentioning--the transom mount on these engines has a built-in stay that flips up to hold the engine up when you're trailering the boat. On my engine I find that this stay makes it almost impossible to get the prop deep enough into the barrel to have the pump submerged. You don't mention how much water you're running it in, but most of the gurus here agree that the pump won't suck water unless you have the seam below the cavitation plate under water. On mine, I don't get a really good stream unless the two screens on the sides of the lower unit above the cavitation plate are fully submerged.

 

[warstoryz]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

Hi cheburashka. Thanks for the information. After reading your post, I am certain I have the lower unit deep enough in the water. I did recieve the Seloc manual yesterday and upon looking at the drawing of the thermostat assembly on page 3-49, I proceeded to remove the thermostat cover and the thermostat at which point I got a very strong stream of water out of the top of the housing. I am not sure what some of the parts pictured along qith the termostat are or what bearing they might have on my problem and I can find no source that offers a kit to replace all these parts, so once again I am somewhat stumped. I did test the termostat and found that it began opening at 152 degrees, but did not fully open until it reached 185 degrees. Since it is a 143degree unit I am thinking it may be faulty. Might I ask you or anyone else who wants to comment, what would be the harm in simply Not installing a thermostat? It seems to me that would keep the engine much cooler anyway. Thanks again, John

 

[itstippy]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

You don't want your motor to run "much cooler". You want it to run at the engineered temperature. When the motor is "cold" and you start it the aluminum pistons expand pretty quickly. The steel cylinders not so quickly. So for a short while you got big pistons in small cylinders. The tolerances allow this, but it's not good in the long term. That's why it's good to warm up an outboard for a few minutes before putting the coals to it. Running a motor in a constantly "cold" state will wear things out much much sooner.<br />It sounds like you need a new thermostat. They wear out and are considered a "consumable", i.e. it is normal to replace them at given intervals.

 

[cheburashka]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

You might want to run it without the 'stat, just to see if you have a blockage in the passages beyond the thermostat. And if it comes down to running it with a thermostat that opens late and running it without a thermostat, I'd err on the side of caution and leave it out. I think the inners on that engine are identical to a number of OMC engines that never had thermostats and still seemed to run reliably.

 

[Paul Moir]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

Yeah, that's a pretty wide range for that thermostat. You can get a new one from Iboats, NAPA autoparts 18-3672. You can get it from your local J/E dealer too with a different part number. The spring and plunger affair underneath the thermostat is designed to open & let water bypass the thermostat when the water pressure gets high. That is when operating at higher rpms.<br /><br />When ordering cooling parts for your '58, it's important to understand that yours is like the '59. There were two different 35hp engines sold in '58 - one like the '57 (no thermostat) and one like the '59 (thermostat). They have different waterpumps and impellers. What P/N is your replacement impeller?<br /><br />With a thermostat in place, the engine will last a lot longer. There's good reasons they went to all the trouble to put one on.

 

[warstoryz]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

Hi Paul. Replacement Impeller I used was <br /># 18-3083. Thanks again to everyone for helping me out. I think I am pretty close to putting this old horse in the water. Once i put in a new thermostat I think she'll be set.

 

[Paul Moir]

Re: 1958 Evinrude Lark 35 Water Pump ?'s

Ok, good that's the right one. I'm not certain that the "no thermostat" one will even fit, but now we're sure.