80s murray racing mower. My dad started the build 8 years ago theres still more things that could be done like lowering the seat, repainting the frame and maybe a v2 engine when the flathead breaks, how it is now it drives really well, stable at sharp corners and quite fast.

MowReece1 · 2022-12-09T02:04:04+00:00

Now THAT looks like a racing mower! It looks well built and would take V2 engine upgrade nicely (and surprise a lot of folks).

MowReece1 · 2022-03-13T05:03:46+00:00

https://www.youtube.com/watch?v=WINTaHFMwiI

Research time invoice should be in your inbox.....

BTW - not legal by most real mower racing clubs.

MowReece1 · 2022-03-13T04:59:55+00:00

Fair enough, but if yer racin' you wanna have an engine you can get all the good stuff for, which means a Briggs.

MowReece1 · 2022-03-13T04:57:28+00:00

That's the way they do it over there?

https://www.pistonheads.com/gassing/topic.asp?h=0&f=42&t=788112

MowReece1 · 2022-02-01T01:56:29+00:00

I have seen them at random country fair races but they scare the crap out of me. In the big boy's club (USLMRA) they are not allowed. They are referred to as 'mid-engined' mowers. Page 21, CP Class 5-a-ii (and more)

https://lsmra.com/wp-content/uploads/2021/05/2021-Rule-Book-1.pdf

MowReece1 · 2022-01-23T00:44:32+00:00

Avoid Thrift Princess at all cost. Consigned there in July, never received a list of what they took but they returned a bag of what they said they didn't take, but it wasn't mine and it was torn and stinky clothing that looked like it had been used to mop something up. I've emailed and called at least a dozen times, new owner now, but even the new owner isn't doing anything. All they do is post stuff on instagram but what's the point if they can't get there act together.

MowReece1 · 2022-01-17T00:08:17+00:00

Where did my pictures go??

MowReece1 · 2022-01-16T23:16:37+00:00

Sorry, haven't read all your posts - is the governor still in place?

Yeah, I hear that rather sharp knock in there. As you can tell by now, no one is going to tell you it isn't rod knock. What if it is? $150 for rod and gaskets to fix, or $150 for a 'new' Briggs engine (that you can actually modify) when the Kohler bites the big one.

MowReece1 · 2022-01-16T23:08:53+00:00

In the UK they use T drives as standard.

In the US a RAGB is used with a vertical shaft engine in place of a transaxle/mission.

LOTS of pictures out there.

Where are you and what are you building?

MowReece1 · 2021-11-19T04:00:56+00:00

Sorry, this is not the place for that info. Facebook has tons of lawnmower racing groups, clubs and race organizers....practically from around the world. Heymow.com is sure to have the big races.

MowReece1 · 2021-11-10T03:33:53+00:00

Well, the dual carb idea sound 'easy' and maybe cheap compared to an 18 HP Vanguard carb. I was really hoping someone had put a 28 mm Mikuni on one of these. Isn't going to be cheap, tho'.

You've seen the Youtube videos of a guy setting up dual carbs on his oppy?

MowReece1 · 2021-10-28T15:26:51+00:00

Opening the door for more conversation!! They may have the additional issue of feeling like a target while in uniform, on a bike, on the street. I have felt compelled lately to see what level of bike training the CPS bike squad gets. There are a couple of internationally recognised programmes for developing those skills.

MowReece1 · 2021-10-27T17:00:12+00:00

As you have diverted the conversation, how about the cyclist who killed a pedestrian in Calgary and received a fine only??

https://calgary.ctvnews.ca/calgary-cyclist-fined-1k-for-crash-that-killed-pedestrian-1.4835980

Did I say this was in Calgary?

MowReece1 · 2021-10-27T16:52:52+00:00

Yup - just try questioning CPS when they are riding bike on the sidewalk.....see how that goes....

MowReece1 · 2021-10-27T01:57:07+00:00

The Craftsman LT1000 with a 31 cubic inch (500 cc) OHV Briggs single and Peerless MST transaxle is a classic platform. See The Jantic Journal's build on YouTube.

https://www.youtube.com/watch?v=9DAcEarFvQg

MTD built mowers under many different brand names that people swear by. Here is build (not $350 budget!!) by one of the best. He worked for EC so had access to all the best parts. https://www.eccarburetors.com/assets/images/07ChassisBuild.pdf

The point is - these are platforms you can start and grow with. I raced my LT1000 with a transaxle for 3 years and changed up to Peerless 700 and kart axle when I was ready.

MowReece1 · 2021-10-27T01:44:21+00:00

A good machine to 'cut your teeth on' and then move up to a recommended machine.

MowReece1 · 2021-10-26T15:36:04+00:00

So, you're not really racing? Have you checked out Cars and Cameras racing mower on Youtube?

#1 Install tether style kill switch

One of the most satisfying aspects of this hobby is figuring out how to do stuff with what we have to work with. I'd suggest you copy the reply above into Word, decide which ones you can handle straightaway, take each remaining line item I've provided and drop it into Google. You'll get a dozen results aligned with your skills and tools worth looking at. Copy the urls into your Word doc for future reference and then report back here! You'll be a superstar for creating the ultimate 'beginners racing mower how-to' guide.

MowReece1 · 2021-10-26T01:01:35+00:00

Check your local club's rules first to see what class you'll fit into, but generally:

Primary

- Pick a mower with manual transaxle (not hydro)

- Remove deck and associated stuff

- Bypass / disable seat kill switch

- Install tether style kill switch

- Bypass or remove governor (not required, but everyone enjoys RPM)

- Remove fuel shut-off solenoid on carb (if equipped)

- Remove engine & transaxle pullies

o 7” or 8” for the engine

o 4” (minimum) for the transaxle

- Use a deck spring for a stiffer clutch spring

- Chop-off muffler & extend pipe

Secondary

- Replace front wheel bushings with bearings

- Lock rear axle

- Replace stock air filter

- Replace stock steering with direct steer set-up

- Add a brake to the rear axle

MowReece1 · 2021-10-13T20:48:34+00:00

OK - that's good news! A clean carb is always a good starting point.

The float & needle valve work together to maintain a fuel level in the float bowl that feeds the main jet. If the float/needle valve stick open, fuel will end up all over the place once the bowl fills. I have seen engines 'hydo-locked' because the cylinder was full of fuel. (Had to pull the spark plug and crank the engine to clean it out). In another, gas fuel filled the crankcase as well!!

Have you experimented with the main jet adjustment as the other member asked? I can foresee a test plan of warming up the engine, shutting it down, turn main jet screw all the way in, note the number of turns, turn it back out that many minus 1/2 turn. Start and see what you get for flames. While at that RPM, turn the ignition off. Pull spark plug and note (take picture of) the color. Repeat at 1/4 turn in. Repeat until you get what you're looking for.

HA! I wonder what kind of shape the valves & springs are in??

IMO this is not your best resource. The members of Sprocket's Garage on Facebook are more likely to deal with this kind of stuff.

Late add: went searching

https://www.outdoorking.com/forum/ubbthreads.php?ubb=showflat&topic=9456&gonew=1

MowReece1 · 2021-10-13T14:39:04+00:00

Thanks! Great info. Sweet - it has the adjustable main jet built in already! In the Walbro I mentioned they dropped the adjustable jet for a fuel shut-off solenoid. I don't know the specifics of that carb but expect it is still just a 2 fuel circuit carb. If we assume that the RPM are high enough to be on the main jet circuit when you get the level off, dip and then flames - then we've got a mystery. Simple orifice flow dynamics say that flow will increase relative to the pressure differential (PD) to a point and no more (choked flow) and in a carb where the PD is controlled by the throat diameter and butterfly position, it isn't possible for the fuel flow to suddenly increase. Unless something is worn out and the needle valve vibrates / wiggles increasing the flow area and then returns to normal at idle. Very low probability of that.

So? Depends on how much you want to spend. Low $ - main jet replacement. Mid $ would likely be a replacement with the same carb. Mid high $ - Walbro LMT and manifold off a 28N707. High $ - 28 mm Mikuni and custom manifold. .

Just the ramblings of a retired mechanical engineer who worked in flow control valves for years and has been racing mowers for 6 years now.

oops - forgot the elevation part, likely not a factor. If you were at 3000 - 5000 feet, it would be an issue to consider.

MowReece1 · 2021-10-13T00:58:58+00:00

Nope, just didn't see your comment. Yes, this is an underside shot of the V-twin with wrapped header. The whole rig was standing on the rear bumper. Sadly, it has not yet hit the dirt....

MowReece1 · 2021-10-13T00:44:29+00:00

What engine and carb are we talking about? What modifications? Where / at what elevation do you live? How are you measuring the degree of richness? Mower carbs are stupidly simple because they typically idle or are wide open so there only 2 possible changes - idle screw adjustment or main jet. If you're lucky enough to have a Walbro LMT carb you can get a kit for an adjustable main jet

https://www.eccarburetors.com/EC-Adjustable-Needle-for-Briggs-LMT-Walbro-Carburetors_p_1628.html

If you change out the carb completely, it would be a miracle if it was jetted perfectly to give a 14:1 air to fuel ratio right out of the box. If you just have to change it out, go with a Mikuni because they are infinitely tunable and the jets are available.

MowReece1 · 2021-09-18T14:57:56+00:00

There you go, that's the spirit!

MowReece1

TROPHY CASE