# Murray 11 36 replacement motor?



## SuthernStylin (Apr 29, 2014)

I bought this thing about a month ago for really cheap, just hoping to at least make it through the season. It cuts great, but the 11hp Briggs in it has been nothing but trouble. It leaks oil like crazy, smokes etc. I was mowing yesterday and it started to Did like it was running out of gas. I parked it toletit cool off cause of the smoke from oil leak I guess? Went and got gas, but it won't start back up. I don't know how to work on these things or where to begin. I'd almost rather replace the engine bc of that. What would be an easy swap for this old Murray 11? Can i get by with say 9 hp from harbor freight? Any help with great details would be greatly appreciated. 


Thanks in advance


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## Ed_GT5000 (Sep 30, 2003)

Don't know what engine you are looking at from harbor freight but I think those are china made cheapos.
If it was me, I would look for a used briggs replacement Craigslist it a good place to start. Check out farm & garden as well as tool section.
But if you are looking at any engine replacement The first thing to do is measure the output shaft of your current engine so you don't have to worry about pulleys and such.


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## SuthernStylin (Apr 29, 2014)

This tell y'all anything


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## Mickey (Aug 14, 2010)

I suspect your Murray has a vert shaft motor. If it does, HF doesn't offer anything large enough to fit the bill. Your current engine has a 400cc engine and the one HF offers is only 170cc. Need to look elsewhere.


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## SuthernStylin (Apr 29, 2014)

Well I figured out what it is. There is 2 linkage rods on the back of carb. There is one with a big j hook/bend in it. I don't know where to hook the other end away from carb at


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## man00 (Jun 18, 2014)

Those engines at HF are pretty darn good. (for the money) I agree go back with B/S


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## jhngardner367 (Apr 5, 2011)

That rod should go from the throttle arm to the governor arm,and the shorter one goes from the linkage to the governor arm. You can get an online PDF manual for it,free. Just google Briggs service manual for your engine #s.


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## yobry1 (Mar 17, 2012)

Hey SouthernStylin, I was in the same boat a couple yrs ago like you when I bought a used murray cheap and these folks helped me out a lot. I suggest you find your model number of the mower(usually under the seat) write it down and google that model number "xxxx-xxxx-xx manual" so you can find the ownsers manual online, then download it and save it to your desktop or print it out for future referrence like I did. Also google the model number with "parts" after it. Searspartsdirect.com and e-replacementparts,com both have great parts diagrams for murray lawn tractors. When you find the parts you need, write down the part numbers and search amazon and ebay for them and pay a lot less for them. You'd be surprised all the mower parts on amazon and ebay.


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## jhngardner367 (Apr 5, 2011)

Dude,
Just find a 12.5 hp OHV Briggs vertical shaft engine ,and put it on. It should bolt right up,as long as the output shaft length and diameter is the same.
You could,actually ,even use a vertical shaft 18 hp twin.


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## Fredneck (May 25, 2012)

a few years ago, the original engine in my craftsman (actually made by murray) blew up, thanks to the factory failing to tighten one of the bearing cap bolts. it slowly worked its way out, and needless to say, the results were catastrophic. happily, at least in terms of my curiosity, it was easy to examine the pieces that came flying out of the new hole in the block and see what had happened.

the original engine was a 14hp B&S. i ended up getting a 17.5hp B&S Intek to replace it, and i'm thrilled with it. love the extra power, allows me to maintain a better speed thru thick stuff than the old engine would. i can't even imagine mowing with 11hp, let alone less, unless your deck is very narrow. in the words of tim taylor... MORE POWER!


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## Fredneck (May 25, 2012)

oh, duh, i'm guessing the 36 in the model number is the deck width. i'd still recommend a horsepower upgrade. seems like even the cheap riding mowers sold these days start around 20hp now.


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## skunkhome (Nov 30, 2008)

We used to mow all day at 3/4 throttle and high gear (about 5mph) with a little 7.25 hp Briggs Cast Iron powering a 42" mower. With the proper setup 11hp is plenty all due respect to Tim Allen. Nice thing about it is that used vertical shaft engines are ubiquitous, cheap and easily interchangeable.


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## Fredneck (May 25, 2012)

well, then what i take away from that is that murray mowers, at least mine, do not have the "proper setup", or else briggs engines aren't what they used to be. certainly, that was not something my old engine would do, and it was 14 horse.


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## jhngardner367 (Apr 5, 2011)

Usually,if the engine holes the block,it's because of some mechanical problem.
Most often it is due to low/dirty oil, governor not set properly, or damaged,fuel in the oil,or in the case of your engine model,the synchro-balancer having worn bushings or a broken synchro-balancer "dog bone".
Under normal use,that engine( model 252707 ) is reliable,and long-lasting. On the few I've seen that had the rod cap come off,it was not due to the factory not torquing them properly,but rather,engine over-speed causing it to vibrate loose .
When ever an engine is tuned,or adjustments made,the FIRST adjustment should be the governed idle and max high speed .
On some of the OHV engines,Briggs sent out a service bulletin about the crankcase bolts being slightly too long,and allowing the bolts to work out,and the oil to leak out and in some cases,the upper crankcase would twist,and break .
Briggs advised replacement bolts,or, to simply trim 1/4" off the bolts,and retorque them.


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## skunkhome (Nov 30, 2008)

Fredneck said:


> well, then what i take away from that is that murray mowers, at least mine, do not have the "proper setup", or else briggs engines aren't what they used to be. certainly, that was not something my old engine would do, and it was 14 horse.


Well I don't want to stick my finger in anyone's eye. I was just saying that hp ratings don't mean much. A few years ago I happened to have my 1974 3414 Simplicity powered by a nearly worn out 13 hp cast iron single cylinder at school to perform some gravel hauling tasks. We had the opportunity (need) to cut the Football practice field. 
The school had a nearly new Sabre 22/54 lawn tractor. The tractor was an impressive looking thing. I decided since I had a 42" mower I would cut the more cluttered areas along the sidelines. I shortly finished my portion and decided to help on the main field. I started in cutting about 1/2 lap behind the Sabre tractor and in short order caught up and found that I could pass him up. Since the two tractors threw the grass in opposite directions we decided to divide the field roughly in two. Short story is I finished my half and had to divide the work again. I ended up cutting most of that section also before the saber got through with its reduced section. I figure I cut about 60% of the field after cutting the field boundaries. I never refueled while the Sabre refueled once and was running out of gas on the way back to the shed. 

My brother has about 7 acre in grass on his place most of which he cuts with a 40 hp Mahindra but there is about 1.5-2 acres around the house he cuts with a finishing mower. For about 20 years he cut this area with a Craftsman 20 Hp Twin with a 50" mower. He wore out the front end on the tractor and replaced the front axle off a junk tractor he found on the side of the road. He wore that out also and then was looking to buy a new tractor. He really never had any other issues with the lawn tractor. A couple of years ago I talked him into buying a 1976 Allis Chalmers 716-6 I found in Indiana that had been repowered with a 16hp Briggs cast iron single. We have a history with AC so he was really looking at getting it for a play tractor. When the tractor arrived he took it off the trailer and gave it a test run on mowing the grass. He was so impressed, after giving it a through going over and buying a new battery he retired the craftsman. This is his second season mowing with the tractor (usually his wife mows with it) and every time he mows, he calls me and brags about how quick it cuts and the high quality of the cut with the 42" mower. He also believes he is using less than half the gasoline he was before. Just saying it is remarkable what you can do if you don't get sucked into the hp race.


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## jhngardner367 (Apr 5, 2011)

A friend,here has a Husqvarna LGT2554,and he mows 5 acres,with it. It does ok,but I do the repairs on it,and he's not kind to it!
One of the biggest problems I have with him(he's 77),is that he sometimes runs it at a low throttle setting,instead of using the speed control,to slow it,when mowing. 
This usually ends up fouling the plugs,or once,stalling the engine. I can't get it through to him,that it has to be set at high throttle,to get a good cut,and that he's actually stressing the engine,and deck.
These engines develope the hp,at certain speeds. That is why they HAVE different speeds. 
The older units,such as Skunkhome's,or mine,were made to WORK,not just cut grass. The newer ones are designed more for smooth lawns, and fast cutting . EITHER way,if the engine is not tuned properly,and the governor isn't set properly,you're going to use more fuel,get poor performance,due to reduced power,and generally stress the engine.
In over 15 yrs of working on these tractors,(and I'm sure Skunkhome has seen this),I've seen many owners "tweak" the governor,and then wonder why it blew the engine . Tractors that are set up the way they are designed,no matter the hp,will do the job they are meant for, but even a tractor with a big hp engine will fail,if it isn't set properly !
So,TUNE it,and SET THE GOVERNED RPMS to the book . It will save you $$$,and do its job .


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## Fredneck (May 25, 2012)

skunk, no problem - but again, i see u say "cast iron". i have a feeling that these engines u speak of are older models which generate more torque than what is sold these days, as a rule.

i know my 14hp briggs with a 46 inch deck would load down far more easily in the same conditions than the 17.5hp engine does. i didn't have the luxury of having an older engine which was most likely a better product 

john - interesting stuff. however, since only one of the bolts worked loose, and the other was still firmly torqued down, i suspect vibration was merely the messenger, not the culprit.


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## Fredneck (May 25, 2012)

and john, i should add a couple of things. i never adjusted the engine, ever. another thing i never did was mow at low throttle. what i DID do, tho, was properly maintain the oil.


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## jhngardner367 (Apr 5, 2011)

Fredneck,
Not saying it was anything you did,or didn't do. An engine can self-destruct for many reasons .
But, normal wear, over 5 years,can leave 1/16 " of slack in the governor,which could let it over speed by about 350 RPMs,or more.
These engines "cycle" at 60 hz,and if they do overspeed,it throws that " cycle " off . That's why it should be checked /reset once a year,or so.
You may not even notice it, but rods can lose one,or both cap bolts,so it can be difficult to tell if it were from a factory goof,or from something else.
When I get a replacement engine,whether used,or a factory new engine,I don't just install it,top off the oil,and run it. I check the governor adjustment,and set it according to the service manual for that engine. I do this,because I know factory engines etc.,CAN be goofed up,and used engines may have been "tweaked " , by the PO .
Even then,S*** happens,and I've had engines fail that WERE set up properly,and a run-in done. One such,was a Kohler horizontal single . Ran up great,and no problems for 3 days. Shut it off,and when I tried to restart it,the rod broke.
Pulled it apart,and the oil was clean,no metal ,no burns,or signs of stress to the rod.It just failed.


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## veeguy (Jun 9, 2014)

Fredneck said:


> skunk, no problem - but again, i see u say "cast iron". i have a feeling that these engines u speak of are older models which generate more torque than what is sold these days, as a rule.
> 
> i know my 14hp briggs with a 46 inch deck would load down far more easily in the same conditions than the 17.5hp engine does. i didn't have the luxury of having an older engine which was most likely a better product


I am currently working on my Briggs 16 HP cast iron engine. I finally got the flywheel off )after a week of effort.) The reason I mention this here is the damn flywheel alone weighs probably 25+ pounds! I can see why this old iron can perform work, just the stored energy in the spinning flywheel can out muscle most new aluminum engines.


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## jhngardner367 (Apr 5, 2011)

Most manufacturers went to the aluminum blocks,to save weight,and have better cooling abilities.
However,they had to make concessions on reliability,due to the stresses placed on the engines.
Also,the new designs often have problems,such as the OHV Briggs engines blowing head gaskets,due to no head bolt near the push rod gallery.
The older engines were made to WORK,and work hard,for many years. Now,it's a case of "planned obsolesence",so it has to be replaced with a new one,rather than replacing parts. This makes them more money than just selling parts.


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