RB240Mike
New member
haha yes you definitely don't need more bottom end
RM 250 Powered Road Race kart
- Thread starter Rickracer
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RB240Mike
New member
Hey Rick where did you get your clutch lever hub and your shifter lever? I think those are the only things I really really need I can't make if I have some time later I might stop by your shop I got a couple questions for ya
RB240Mike
New member
really? it looks amazing in person I thought the shifter might be home made but really thought the clutch lever he bought
Rickracer
RM250 Race Kart Driver
Yes Mike, I fabricated both pieces, actually the steering hub is just "modified" to add the pivot for the clutch lever. I could do yours too, and make you a clutch lever just like mine. Just bring me the steering hub and some 1/2" square tubing, 
RB240Mike
New member
I'll do that and buy ya some lunch!!!
RB240Mike
New member
Hmmm they have a new clutch lever I didn't see last time I checked on TSracing I think I'm gonna try first because it's only like $30
Rickracer
RM250 Race Kart Driver
It was there before, you just didn't see it,
RB240Mike
New member
quite possibly haha I kinda decided on a even cheaper way right now haha I wanna get the kart together and running with he essentials then buy the nicer stuff
Rickracer
RM250 Race Kart Driver
I hope you're not trying a bike clutch lever, I did one of those the other day on a customer's kart at their request, it really didn't work and I wound up having to make it like mine. This was on a factory built shifter kart, I had to duplicate my throttle linkage and clutch linkage. Somebody had added a bracket on the steering shaft to use a different clutch cable, then the cable broke, the new cable was too short, so I converted it back to the same setup as it had, with an adjuster added, which made the new cable long enough. I'll be racing that guy at CFRC soon.
jr dragster T
New member
Hey Rick, Is this motor equipped with Powervalves?
RB240Mike
New member
darn that is what I was thinking :/ o well anyways made my motor mount and ordered the ignitor I needed so I think the only 2 things I really really need are chain and sprocket/gear. Have you been out to CFRC lately?
RB240Mike
New member
i envy the amount of room you have on your kart haha I'd say my motor is at least 1/3 larger.. I kinda wish I had gone with something about the size of your motor now
Rickracer
RM250 Race Kart Driver
Tyler, my motor is a pre power valves era '84,
From what I've seen, I'm kinda glad of that, I've seen a few power valve failures, that's one less thing for me to worry about.
Mike, the bike clutch lever would release and re-engage the clutch, but didn't really have enough leverage to be able to do it smoothly, causing it to either stall or burn the tires, you just couldn't feather it out to get a smooth start. I finally got all my bodywork mounted, and plan to get to CFRC one of these weekends, but I've been kinda busy working on the Vega, since the 400 that was/is in it spun a rod bearing, I'm building a 355 I've had tucked back for a rainy day, should be about 565~575 hp, (without either of the 2 nitrous plate systems I have,
), should wake that little Vega RIGHT up,
From what I've seen, I'm kinda glad of that, I've seen a few power valve failures, that's one less thing for me to worry about.
Mike, the bike clutch lever would release and re-engage the clutch, but didn't really have enough leverage to be able to do it smoothly, causing it to either stall or burn the tires, you just couldn't feather it out to get a smooth start. I finally got all my bodywork mounted, and plan to get to CFRC one of these weekends, but I've been kinda busy working on the Vega, since the 400 that was/is in it spun a rod bearing, I'm building a 355 I've had tucked back for a rainy day, should be about 565~575 hp, (without either of the 2 nitrous plate systems I have,
), should wake that little Vega RIGHT up, 
anderkart
Moderator
Speaking of shifter-kart power valves... I was surprised to resently learn the brand new CR125 engines Honda sells specificly for shifter kart racing dont have powervalves either.
I was told its been this way for quite awhile because the higher rpm ranges shifters tend to maintain on road race type courses never realy requires the widened powerband anyway. The races begin with a brisk rolling start and from there the rpm's never dip low enough to utilize any advantage the various Honda powervalve systems might have to offer. So basicly they were just found to cause aditional maintenance/weight without lowering lap times on shifter kart tracks.
I'm still not sure if the curent Honda's CR-80 shifter class engines use power valves or not.
I was told its been this way for quite awhile because the higher rpm ranges shifters tend to maintain on road race type courses never realy requires the widened powerband anyway. The races begin with a brisk rolling start and from there the rpm's never dip low enough to utilize any advantage the various Honda powervalve systems might have to offer. So basicly they were just found to cause aditional maintenance/weight without lowering lap times on shifter kart tracks.
I'm still not sure if the curent Honda's CR-80 shifter class engines use power valves or not.
jr dragster T
New member
I've rebuilt a 2004 CR85 top end for a customer and that bike was not equipped with power valves. Sorry Rick, Once I took a close look at your engine I realized it didn't have power valves either. I know my freinds 1998? RM250 has power valves though.
600ccdeathkart
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brakes
Rick,
I didn't see where you got the brakes I've been looking for awhile I found some on Ebay but they got too rich for me they went over $350.
Rick,
I didn't see where you got the brakes I've been looking for awhile I found some on Ebay but they got too rich for me they went over $350.
Rickracer
RM250 Race Kart Driver
I found them on http://karting.4cycle.com/index.php? , I don't remember now if I found an ad, or posted looking for brakes, but I bought them from a guy in Cali for $200 + shipping. He had some more too, if you want, P/M me and I'll try to get you in touch with him. 
Rickracer
RM250 Race Kart Driver
I know it's been forever since there was an update to this thread, but I've just got too may irons in the fire to keep them all stoked at the same time. :toetap05:
I finally took the kart to the road course, they sent me an email about an Owner/Operator Appreciation Day. What normally costs $50 for 3 hours, was 4 hours +, for free. All I can say is.....
HOLY SH*T BATMAN!!!!!
It was the 3rd fastest kart there, and only not the fastest by far because of: (1), no front brakes, (2), carb bogging badly at anything over half throttle, and (3), fuel pickup in the wrong place.
No front brakes because I strap-started the kart on July 4th weekend on my (patent pending, once I get the bugs worked out, :biggrin5, roll-up kart lift, which means throttle partially opened, and in 3rd gear. When it fired, it went to about 6 grand and started vibrating quite a bit, probably from one of the back tires being flat for a while, even though it was aired up when I cranked it. Well, it vibrated off the stand and took off on it's own, turning about 5 or 6 grand in 3rd gear, down the driveway, across the street, and into the neighbor's yard across the street, smashing into a tree. Fortunately, no cars or pedestrians were in the street, and no one was in her front yard. The only damage to the kart was a broken front rotor, and of course, the scar in the tree. Rotor = "Made in Italy, $93 + shipping", 
I think the carb problem is just from it sitting up for too long, gonna give it a good cleaning and see what happens with it. After I took the rotor off and set the brake balance bar to all rear and no front brakes, I drove around the neighborhood for about 15 minutes, but there was no place to even think about going full throttle at all, so I didn't know how bad the carb was til I got to the track.
All the high $$ race karts have their fuel pickups going in the top of the tank, with a weighted, swinging pickup that can follow the fuel. Mine is at the right rear of the tank (typical oval track tank), once it gets near half a tank, high G right turns have the fuel pump sucking air til the track straightens out again. Next time out. mine will have a swinging pickup as well,
The two faster karts were both GREAT running 125 shifter karts, which are supposed to have like 35 hp stock, (99 CR125), and as much as 45~50 when properly modified. My old dinosaur (93) RM250 motor is supposed to be 42 hp stock, with the pipe and K&N filter, let's say...maybe 45. But the other two would pull hard right from the turns and keep shifting, putting 5~10 kart lengths on mine...til it stopped bogging spitting and sputtering, then it would reel em back in almost like they put the brakes on, right on their bumper, even go around em on the outside if it was a long sweeping turn, next tight turn, they'd go by, and the whole thing would start all over again. One person standing on the observation platform said they actually saw it pull the front wheels coming out of the tight left-hander in front of the platform, it felt like it to me as well, but I wasn't sure til they came to me and said so too. That ain't horsepower, it's TORQUE,
All in all, this thing is even more of a BEAST than I thought it would be, and I had some pretty high hopes. I promise to get video next time, there was just no time this time around, I was thrashing on the kart right up till midnight Friday night to get it ready and loaded up for Saturday morning.
I finally took the kart to the road course, they sent me an email about an Owner/Operator Appreciation Day. What normally costs $50 for 3 hours, was 4 hours +, for free. All I can say is.....
HOLY SH*T BATMAN!!!!!
It was the 3rd fastest kart there, and only not the fastest by far because of: (1), no front brakes, (2), carb bogging badly at anything over half throttle, and (3), fuel pickup in the wrong place.
No front brakes because I strap-started the kart on July 4th weekend on my (patent pending, once I get the bugs worked out, :biggrin5
, roll-up kart lift, which means throttle partially opened, and in 3rd gear. When it fired, it went to about 6 grand and started vibrating quite a bit, probably from one of the back tires being flat for a while, even though it was aired up when I cranked it. Well, it vibrated off the stand and took off on it's own, turning about 5 or 6 grand in 3rd gear, down the driveway, across the street, and into the neighbor's yard across the street, smashing into a tree. Fortunately, no cars or pedestrians were in the street, and no one was in her front yard. The only damage to the kart was a broken front rotor, and of course, the scar in the tree. Rotor = "Made in Italy, $93 + shipping", I think the carb problem is just from it sitting up for too long, gonna give it a good cleaning and see what happens with it. After I took the rotor off and set the brake balance bar to all rear and no front brakes, I drove around the neighborhood for about 15 minutes, but there was no place to even think about going full throttle at all, so I didn't know how bad the carb was til I got to the track.
All the high $$ race karts have their fuel pickups going in the top of the tank, with a weighted, swinging pickup that can follow the fuel. Mine is at the right rear of the tank (typical oval track tank), once it gets near half a tank, high G right turns have the fuel pump sucking air til the track straightens out again. Next time out. mine will have a swinging pickup as well,
The two faster karts were both GREAT running 125 shifter karts, which are supposed to have like 35 hp stock, (99 CR125), and as much as 45~50 when properly modified. My old dinosaur (93) RM250 motor is supposed to be 42 hp stock, with the pipe and K&N filter, let's say...maybe 45. But the other two would pull hard right from the turns and keep shifting, putting 5~10 kart lengths on mine...til it stopped bogging spitting and sputtering, then it would reel em back in almost like they put the brakes on, right on their bumper, even go around em on the outside if it was a long sweeping turn, next tight turn, they'd go by, and the whole thing would start all over again. One person standing on the observation platform said they actually saw it pull the front wheels coming out of the tight left-hander in front of the platform, it felt like it to me as well, but I wasn't sure til they came to me and said so too. That ain't horsepower, it's TORQUE,
All in all, this thing is even more of a BEAST than I thought it would be, and I had some pretty high hopes. I promise to get video next time, there was just no time this time around, I was thrashing on the kart right up till midnight Friday night to get it ready and loaded up for Saturday morning.
88s10Durango
New member
Still need some vids Rick , lol , Bill ..
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