Slightly off topic, old 2 stroke lawnmower engine thoughts

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anlinkay

anlinkay

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2 stroke iron horse lawn mower engine as fitted to outboard motor

has anyone out there got any info on 2 stroke iron horse lawn mower engines as fitted to outboard motor, sometimes known as dolphin. I have an old one which im trying to restore , it has a bing carburettor and I need more info on this type and numerous other tech details , any info would be much appreciated thanks I no its old but its a very good one so would like to get it to go properly photos also would be appreciated thanks
 
old 040

old 040

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has anyone out there got any info on 2 stroke iron horse lawn mower engines as fitted to outboard motor, sometimes known as dolphin. I have an old one which im trying to restore , it has a bing carburettor and I need more info on this type and numerous other tech details , any info would be much appreciated thanks I no its old but its a very good one so would like to get it to go properly photos also would be appreciated thanks

i believe i've read about the dolphin somewhere, but that was a long time ago, may want to check "the old outboard book", you may have some luck there for info.................................found this custom mower on the net a few months ago, pretty slick.......................View attachment 312592View attachment 312593View attachment 312594
 
67L36Driver
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312592-cimg0062-jpg



Someone had way too much time on their hands.:msp_wub:


The same can be said for us saw cranks.....................................................................................
 
zogger

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i believe i've read about the dolphin somewhere, but that was a long time ago, may want to check "the old outboard book", you may have some luck there for info.................................found this custom mower on the net a few months ago, pretty slick.......................

Tim the Toolman meets Hank Hill meets the Jetsons meets Batman!!
Every boy *needs* one!
 
Zombiechopper

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just saw this thread hiding in the background.

I have been running Stihl Ultra at 50:1 or 40:1 (whatever I have mixed for saw gas) in my two D series lawnboys for years now. Burns clean and the mowers seem to run nice and cool on it. These are big two strokes with relatively low compression, big bearings and very low RPM's. They do just fine on pretty much any oil and a good synthetic at 50:1 works just dandy.
 
Rusty Barlow

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i've been using echo's two cycle oil for years now, i've owned, and still own many oldies, but i do run them at a richer mix, around 32/1 with no issues, here's a pic of one of my rarest two strokes using this mix, it's a power products "free air" twin, yes, it's running in the photos..................View attachment 294734................;)View attachment 294736

I know this is a zombie post quote, but gahdam! A vintage 2 stroke boxer lawnmower - that's cool!
 
Hddnis

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I can see doing the underside with bedliner material on my next new mower. But, Lawnboy don't build two stroke engines anymore.



I tried bedliner on the underside of a mower deck and it didn't work at all. Prep was top notch, sandblasting, etching primer and then bedliner. I also tried it with a deck that was only sandblasted and it was worse. These were commercial mowers running 50+ hours a week, but the bedliner still failed within just a couple of months. It might last a few years on a personal use mower.



Mr. HE:cool:
 
splitpost

splitpost

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run the oldies on whatever you use in your modern stuff,i got a 40yr old victa that dad gave me when I left home and I been running it whatever I been using the most, its badged to run BP zoom ,when I had my cr500 the old mower ran 33:1 then back to 25:1 when it was the only two stroker I owned,
now I run all my stuff on 25:1 mixed with synthetic,the old girl still goes today although I have better means to cut with now ,she still gets fired up now and then
 
Miles86

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Howdy:

You really should follow the Lawnboy directions and use an ASH LESS 2 stroke oil. Your LB motors has an iron cylinder, and is very low rpm and HP.

Low Ash oil will not burn hot enough in your LB and the ash will just form lots of deposits due to the low temperatures. AshLESS oils will be much better make sure it's NMMA certified on the bottle. (Rust protection).
 

7600

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My lawnboy was made in the 90's. I used Pennzoil air cooled oil in it for years. Have been using echo power blend at 50:1 since 2009. No problems.
 
zogger

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I tried bedliner on the underside of a mower deck and it didn't work at all. Prep was top notch, sandblasting, etching primer and then bedliner. I also tried it with a deck that was only sandblasted and it was worse. These were commercial mowers running 50+ hours a week, but the bedliner still failed within just a couple of months. It might last a few years on a personal use mower.



Mr. HE:cool:

When I lived in the salt on the roads belt, in ye olden daze, we used the drain oil as rust proofing under the cars.

Well, some people did, I sure did, hate working on rust buckets...

Do it in the summer, dry day, go to car wash, blast it all off underneath, drive home, it is dry by then, change oil. While oil is still hot and in the drain bucket, any old paint brush and have at it underneath, everywhere.

Might work on mower decks, don't know, just thought about that old trick....

Two birds, one stone, etc. it worked too.
 
saxman

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I have two F series Lawn Boys from the mid 80's and I use 50:1 Stihl Ultra that I keep for my saws. They run great with no smoke like the old Lawn Boy mix produced. I use his same mix in all my vintage chainsaws as well with no issues

Steve
 
2twins

2twins

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I have an old alloy deck Toro two stroke mower that I Bought in 1988 and A Kawasaki Hedge Trimer and Kaaz (TU26 Mitsubishi engine) strimmer (weed whacker) that all run 50:1 Stihl Ultra that I use in my chainsaws. The Kaaz and Kawasaki both originally ran on 25:1 and seem to run better on 50:1 synthetic. The old Toro motor recently failed as the balls from the top caged roller crank bearing started to escape and the crank counterweight knocked a chunk off the piston skirt. However, when I stripped the engine the failure was not oil related the cylinder walls and piston walls were fine. I think that years of the mower mowing half an acre on a 1:4 slope and hitting detritus roots etc over the years had physically damaged the bearing and it just wore out!! 25 years of use seems ok. The top and bottom bearings were easy to get here but the piston and rings less so I'm on the lookout for an old engine to cannabalise! :)
 
naturelover

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The used oil under the mower deck seems to work okay, but comes off if you wash it much.

I started painting mine after every season, will see if that works better. It's working better than the oil so far.




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redfin

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I have question for you 2stroke lawnmower gurus. I just rehabbed my old 21 lawnboy that I had put away years ago because it would not start.

Do I need to run this thing at full throttle like a chainsaw? I don't cut the entire yard with my pushmowers only aroune bushes and trees the tractor can't get. The grass is not ever a heavy load on the mower.
 

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