# engine swap



## mowerman42 (9 mo ago)

im doing a project on a mower and i want to race it currently has no engine what is a big powerful engine i can use and where can i find it thanks


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## pogobill (Jan 31, 2012)

Welcome to the forum. If you're asking about a big powerful engine, you may be in over your head already. 

Some details would be in order, I think. What type of mower.... front engine, rear engine? Brand of mower you have and a few numbers on model and serial number. This would give the members a bit of information to lead you in the right direction. 
Here's some food for thought.....








Honda’s 150MPH, CBR1000RR-powered Riding Lawn Mower


A test ride review of the world’s fastest riding lawn mower, Honda’s Mean Mower.




www.cycleworld.com


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> im doing a project on a mower and i want to race it currently has no engine what is a big powerful engine i can use and where can i find it thanks


OK, define "race".... Are you talking about organized events? You realize that "sanctioned races" have rules and classes? You can't just slap a big engine on a stock mower and show up. When you go to a sanctioned event, the first thing that happens is your machine goes through "Tech Inspection". That's where it gets inspected to see if it meets the rules. Like any form of racing, it's not cheap. Most guys that are serious will spend $2,500 - $5,000 on a machine depending of what class they run. The upper class machines are basically go-karts that look like lawnmowers and can 60MPH on a 1/4 mile oval track. The Pro's (Yes there a professional lawn mower racers) that run the top "unlimited" class can reach speeds of 100MPH

Don't know about Canada, but here in the U.S. most organized events are sanctioned by the USLMRA. Here's a link to their 2021 rule book.....

USLMRA 2021 Rule Book

Local USLMRA Race


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## pogobill (Jan 31, 2012)

I don't believe there no governing association in Canada, but there are a few racing associations, particularly in Ontario.


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## Bob Driver (Nov 1, 2017)

pogobill said:


> I don't believe there no governing association in Canada, but there are a few racing associations, particularly in Ontario.


Looks like there is nothing like the nationwide USLMRA up that way. It's more of a "club" thing, but you can bet there are still rules. Two kinds of people that cheat whenever possible .... Politicians and Racers

Here's a link to the Western Ontario Outlaws rule book. It's the "Outlaw Class", so almost anything goes, but you'll see what I mean by them essentially being go-karts that look like lawnmowers
Outlaw Class Rules

Looks like that start next month and run through October and the track is at a place called Petrolia......


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## mowerman42 (9 mo ago)

pogobill said:


> Welcome to the forum. If you're asking about a big powerful engine, you may be in over your head already.
> 
> Some details would be in order, I think. What type of mower.... front engine, rear engine? Brand of mower you have and a few numbers on model and serial number. This would give the members a bit of information to lead you in the right direction.
> Here's some food for thought.....
> ...


its a front engine no idea what brand or model


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## mowerman42 (9 mo ago)

Bob Driver said:


> OK, define "race".... Are you talking about organized events? You realize that "sanctioned races" have rules and classes? You can't just slap a big engine on a stock mower and show up. When you go to a sanctioned event, the first thing that happens is your machine goes through "Tech Inspection". That's where it gets inspected to see if it meets the rules. Like any form of racing, it's not cheap. Most guys that are serious will spend $2,500 - $5,000 on a machine depending of what class they run. The upper class machines are basically go-karts that look like lawnmowers and can 60MPH on a 1/4 mile oval track. The Pro's (Yes there a professional lawn mower racers) that run the top "unlimited" class can reach speeds of 100MPH
> 
> Don't know about Canada, but here in the U.S. most organized events are sanctioned by the USLMRA. Here's a link to their 2021 rule book.....
> 
> ...


just something that i can play around on with a few buddies


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## Bob Driver (Nov 1, 2017)

"Big Bore" Kohler (83mm)....... CV25, 730, 740, 750.

25, 730, 740 have the shorter stroke (67mm) so you can get more RPM out of them. 750 has a 69mm stroke, so it has more low end torque. 67mm on an oval track..... 750 on a road course, or off-road muddin'

New.... Any of those will run $2,000 +. Used they run $200-$300. O/H (including machining if it needs to go oversize) will run about $500 for just machining/parts. It's generally about 8 hours if there is a labor charge


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## mowerman42 (9 mo ago)

is this it? https://kohlerpower.com/en/engines/product/command-pro-cv730


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> is this it? https://kohlerpower.com/en/engines/product/command-pro-cv730


That's one of them..... 83mm bore x 67mm stroke


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## mowerman42 (9 mo ago)

ok is it 2000$ us or cad?


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## Bob Driver (Nov 1, 2017)

Bob Driver said:


> That's one of them..... 83mm bore x 67mm stroke


You need to dump the transaxle/belts and go to a "live axle" like a go-kart.... To do that, you'll need a Peerless 700. It allows you to go to chain drive and gives you 5-speeds. This is where you get the 60MPH by playing with sprocket ratios


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> ok is it 2000$ us or cad?


Pick your HP.... ECV's are EFI engines, you'll need a laptop/software to tune the fuel map. CV's are carb, you just need a screwdriver and a handful of main jets
Kohler Verticals


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## mowerman42 (9 mo ago)

Bob Driver said:


> Kohler Verticals


ok where would i put the peerless?


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> ok where would i put the peerless?


Installing Peerless 700/Live Axle


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## mowerman42 (9 mo ago)

Bob Driver said:


> Installing Peerless 700/Live Axle


ok ill order one then


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> ok ill order one then


Peerless 700 E-bay


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## mowerman42 (9 mo ago)

Bob Driver said:


> Peerless 700 E-bay


cant get that it doesnt ship to canada


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> cant get that it doesnt ship to canada


Just an idea on price and what you're searching for in the way of a model. Actual acquisition is going to be up to you. They're all over the inter-net, pick one. Sounds like you better do some deep research before you start buying stuff for this project

Installing a Peerless 700 and a live axle set up in a lawn mower chassis are complicated projects that require a high level of welding/fabricating skills. You want to run a clutch, or a torque convertor between the engine and the Peerless? What size sprockets/chain from the Peerless to the live axle. What size axle/bearing set up are you thinking about? You're going to need hydraulic disc brakes all the way around now that your 500lbs machine will run 60MPH. Surely you're not figuring on leaving that 8-10 MPH steering system in it? What are you going to do for a variable speed throttle, you can't use the lawn mower friction throttle and just nail it wide open. What size/style of tires are you going to run? How much are going to lower the seat mounting. There's a lot to be considered........

All you're basically going to use on the lawnmower you have is the frame rails and the body tin (you're actually building a racing go-kart that looks like a lawnmower) You'll be amazed at what this is going to take in the way of $$$, time, and skills. That link I sent you about installing the Peerless 700 is a whole series of that guy building a racing lawnmower. I highly suggest you watch the entire series so you know what you're getting into before you start buying parts. If you're actually serious about buying a *new* Big Bore Kohler for this machine, my guess is you're going to be $3,500 - $4,000 and 100-150 hours into this project by the time you're ready to take it for the first test run.


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## LouNY (Dec 15, 2016)

Ah the heck with a Kohler, get you a Yamaha 1200 or 1300 V4 out of a Yamaha Venture bike.
That would make one heck of a lawn mower.


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## SidecarFlip (Mar 25, 2021)

probably a ton of them in salvage too. I think that is where the 'Super Kart' drivers get their engines at. Not sure if it would mow the lawn but it would flatten your hair for sure.


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## LouNY (Dec 15, 2016)

They ran pretty good in an 800 pound touring bike, I've got two sitting here I should get rid of.
Haven't ridden them hardly a bit since I got the 14 Harley and haven't ridden it much the last two years.


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## Bob Driver (Nov 1, 2017)

LouNY said:


> Ah the heck with a Kohler, get you a Yamaha 1200 or 1300 V4 out of a Yamaha Venture bike.
> That would make one heck of a lawn mower.


SOS.... Anybody can get the power coming off of a big engine... How do you put it to the ground, how do you stop it, and how do you keep the damn thing pointed in the direction you want to go? All things that need to be considered, unless you're just bat crap crazy like this guy...

Bat Crap Crazy with Mechanical Skills


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## pogobill (Jan 31, 2012)

Looks like he could be one of our members!! LOL


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## Bob Driver (Nov 1, 2017)

pogobill said:


> Looks like he could be one of our members!! LOL


Yep.... I'm thinking Bontai Joe from some of his post, or I can see FredM in his younger days down under


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## FredM (Nov 18, 2015)

Bob Driver said:


> Yep.... I'm thinking Bontai Joe from some of his post, or I can see FredM in his younger days down under


I don't have the bushy beard Bob and yeh! me and a Kiwi mate in the 70's built a drag bike from the ground up, built a moly tube frame and fitted a Ford 1500CC OHV Cortina motor crosswise, started with a single 45mm side draft Weber, upgraded to twin 45mm side draft webers when I could afford it,
Tiger cub front forks with a Honda step through front wheel assembly, remember the 350CC Bridgestone two stroke that come out back then Bob??, we used the rear wheel assembly from that bike and the rear brake was crap, I had a very rare BSA 4 speed gear box with the Trumpy shift and we incorporated Jawa speedway clutch parts with the BSA box, worked quite well too, The owner of a transport depot that we used to frequent a lot made us a fuel injected setup just using a helix assembly, didn't that engine rev, I can still hear it, sadly there was no low down power where it was needed on the line, so we went Weber, my Kiwi mate had one ride and he told me I can have it, he wasn't riding again, we talked about using a bit of Nitro and I wish I had at least tried a small percentage, the trouble was having to rely on the small front brake because the rear brake was useless, and the jetting for the carbies and by now the Ministers for war and finances started to get in our ear about spending so much money on the project, so eventually we broke the bike down for parts and sold off what we could, my Kiwi mate had to pack up and take his family back home as his father wasn't faring too well.

The most annoying part is there was only a couple of photos taken of the bike and I don't think I have any copies here, I know my mates wife had a copy but she has MS and I doubt if she would be able to find them now.

From memory, the best we got from the bike was very low 12's and about 109 MPH for the standing Quarter.

I also drove midget speedcars at out local track, I had a sponsor (owned a car wrecking yard) who owned the car and I did the work and looking after the car, also helped the owner build a modified dirt track car which is built out of any small car, I think we used a 1000 Datsun as the base and fitted a 186CI red Holden engine and gear box (GM) and I drove that a few times until his wife started to get in his ear about costs also, so that was short lived too.

I guess I could be classed as crazy and at my age, I would still throw my leg over a motorcycle if I got the chance, I keep hoping this may happen sometime soon.

Sorry Bill, if this is not pertinent to this thread, please shift to Bob's latest thread.


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## Bob Driver (Nov 1, 2017)

FredM said:


> I don't have the bushy beard Bob and yeh! me and a Kiwi mate in the 70's built a drag bike from the ground up, built a moly tube frame and fitted a Ford 1500CC OHV Cortina motor crosswise, started with a single 45mm side draft Weber, upgraded to twin 45mm side draft webers when I could afford it,
> Tiger cub front forks with a Honda step through front wheel assembly, remember the 350CC Bridgestone two stroke that come out back then Bob??, we used the rear wheel assembly from that bike and the rear brake was crap, I had a very rare BSA 4 speed gear box with the Trumpy shift and we incorporated Jawa speedway clutch parts with the BSA box, worked quite well too, The owner of a transport depot that we used to frequent a lot made us a fuel injected setup just using a helix assembly, didn't that engine rev, I can still hear it, sadly there was no low down power where it was needed on the line, so we went Weber, my Kiwi mate had one ride and he told me I can have it, he wasn't riding again, we talked about using a bit of Nitro and I wish I had at least tried a small percentage, the trouble was having to rely on the small front brake because the rear brake was useless, and the jetting for the carbies and by now the Ministers for war and finances started to get in our ear about spending so much money on the project, so eventually we broke the bike down for parts and sold off what we could, my Kiwi mate had to pack up and take his family back home as his father wasn't faring too well.
> 
> The most annoying part is there was only a couple of photos taken of the bike and I don't think I have any copies here, I know my mates wife had a copy but she has MS and I doubt if she would be able to find them now.
> ...


I knew it..... That's exactly why I mentioned your name. Awesome mechanical skills and just barely enough common sense/luck to have survived it. Although Burt Munro was a Kiwi, I watched "The World's Fastest Indian" a few weeks ago and I couldn't help but think of you

Bravo to you mate...... You are a hero in my book


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## FredM (Nov 18, 2015)

Yeh!!, I really liked that story on Bert Munro, I have watched the movie a few times and what got me in was the fact the Indian had 4 valves per cylinder and I think this was 1923, when you think about it, those oldies were quite advanced mechanically for the age period, really astounds me what they were doing back then.

Have you ever seen the engine breakdown of the inverted Daimler V12 used in the ME109??, if you haven't, it may interest you somewhat seeing it was built around 1932, I have a see through drawing if you are interested.


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## SidecarFlip (Mar 25, 2021)

The one thing that vintage bikes lacked were good brakes. Have as friend with a Vincent Black Shadow that goes like a raped ape. Problem is, it cannot stop very well.


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## mowerman42 (9 mo ago)

LouNY said:


> Ah the heck with a Kohler, get you a Yamaha 1200 or 1300 V4 out of a Yamaha Venture bike.
> That would make one heck of a lawn mower.


yeah that would


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## Bob Driver (Nov 1, 2017)

mowerman42 said:


> yeah that would


Well, you should have said that's the kind of racing you wanted to do..... These guys are running in-line 4-cylinder bike engines

Mower Drag Racing


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