RM 250 Powered Road Race kart

[Rickracer]

Actually found out it's NOT a Margay, not sure what it is, maybe an Emmick?
Here's a few pics...not really that current though, got a belly tank now and a few other mods...

Here's one out on the road course:

Brakes:

These are the most current ones, yesterday in fact:

I'll be taking more as I get into Stage II, installing the Suzuki RM250 motor, extra master cylinder and front brakes, shifter and clutch linkage, etc.

 

[kitcarguy]

Looks good Rick. Did you pick that up local?

 

[Rickracer]

Yes, one of the local roundy round kart guys sold it to me for $125 as a rolling chassis, gave me a spare motor mount, scared me up a clutch for $20, has given me a few tires and an extra rear wheel, and loaned me his tire changing equipment. He's got a several oval karts and a KE 85 shifter kart, I've been trying to get his butt out to CFRC to run it, but it's still got a couple bugs in it and he's been busy.

 

[jr dragster T]

Nice kart, Header is too short though. From flange to end it should be about 16-18" long.

 

[anderkart]

Cool kart Rick...

 

[Rickracer]

Nice kart, Header is too short though. From flange to end it should be about 16-18" long.

I guess looks can be deceiving, it's actually 20.5" flange to end, and the muffler is incorporated, sort of like a glasspack with no glass in it. I drilled 2 rows of (5) 5/16" or 3/8" holes all the way through the pipe at 90° to each other, then slipped the bigger diameter pipe over that section of pipe and welded it. It's mellow enough to keep the neighbors from complaining, but you can still hear it pretty well on the track.

 

[Rickracer]

Stage II begins.....

Motor Mount:

Mods to the Expansion Chamber:

Working on trying to find a hub and 23 tooth sprocket for this 520 chain now......more pics as I make more progress.
BTW, I fired it up last night too, sounds like it's gonna be NASTY FAST!!!!

More pics. Since I'm adding front brakes, I added another master cylinder as well, which causes a need for a bias adjuster too. Since I'm such a cheapskate, I made my own.

This will allow me to adjust which end grabs harder, or balance them out.

 

[anderkart]

Sweet, nice job man !

 

[jmorey92]

hers a 22 tooth sproket cheap
http://www.denniskirk.com/jsp/produ...Id=&productId=p8104322S&leafCatId=&mmyId=7856

 

[Rickracer]

Thanks, that is pretty cheap. I ordered a hub and sprocket from QRC yesterday, I hope it works well. Once I get it all together and test a little bit, then I'll blow it all apart, paint it up and make it look good. Right now I'm jonesin for some adrenaline rush,

 

[jmorey92]

what size sproket did it have before what top speed are you looking for?

 

[Rickracer]

It had a Honda 8 horse (about 12~13hp after mods, ) on it before, with 15/63 gearing, topped out about 65 or so. With the (40 hp) RM 250 motor, all the 125cc shifter kart guys are running around 1.53 to 1.8x final drive gearing. IIRC, 5th is actually slightly overdriven. Theoretically, it should do just short of 200 mph, but I probably will do good to hit 100 on the racecourse. I can swap to a tooth smaller or bigger front sprocket for a sizable change, and the front sprockets are only like $8~$12 each.

 

[jmorey92]

lol 200 id gear it to hit like only 120 or something so you get tons of toqure and it will do crazy burnouts and dounts on demand. because whats the point of havings the gearing to do 200. unless you plan on doing it.

 

[Rickracer]

Because I race on a road course, and all the shifter karts are geared about the same. If I can use more gear, it's a simple and cheap 10 minute swap to put in a higher or lower front sprocket. I know this thing is gonna be a handful to begin with, and I don't wanna be spinning out all over the place and get kicked off the track. It would do donuts easily with the Honda motor on it, so I know it will with this 40 HP monster on it, especially with a clutch, burnouts too. Once I get some seat time, I'll adjust the gearing to how the kart runs. I plan to do some 1/8 mile drag racing with it too, so I'll definitely be getting some alternate gearing a little later on,
May have to rig up a manual line lock too,

 

[jmorey92]

i see... im so jeolous i want a shifter kart so bad even just a frame because i want to do like 80 - 100 down the road and watch the cops try to catch me... lol

 

[Rickracer]

If a motorcycle engine is in your plans, better find a newer race frame to start with. This one is gonna be marginal at best, and I'm keeping my eyes open for a better chassis, once I find one, I'll put the Honda motor back on this one for a 2nd kart,

 

[crazycart]

What year is the RM engine? Better wear a diaper that's all i can say...

 

[Rickracer]

It's a 1990,
I don't think I'll be needing a diaper, I used to drive a 600hp 427 Vega on the street, (900 with the NOS turned on), this kart will hopefully get me about that same kind of adrenaline rush. BTW, did I mention that I'm an adrenaline junkie???

 

[Rickracer]

Added some more pics, of the brake bias adjuster. Next up is the shifter and the clutch lever. Waiting on bearings, a new seat, some more tires, and a clutch cable. :rolleyes3: :rolleyes3:

 

[Rickracer]

Got my new seat, pics later....