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Danny Lerner
Joined: 08 May 2005
Posts: 188
Location: United States, New York,
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 Posted: Wed Nov 23, 2005 1:51 pm Post subject: |
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I actually own and hand built my 500cc shifter. Believe me - I know what fast is... I am not looking for insane speeds in this kart I am going to build... I am looking for 2 stroke 125cc speeds/acceleration - in a reliable package that is low maintenance, cheap, electric start, isn't fussy, and is SCCA legal.
I understand that if I use the kart solely for autoxing (as I will most likely do - other than some parking lot fun) - the service intervals are infrequent.
The simple matter of fact, is that, 2 stroke motors are fussy. They don't like to start half the time, they want you to carry a change of jets along, they are annoying to mix fuel for, they smoke, they won't idle, they have terrible reliability, the list goes on...
Basically, I want a cheap, low maintenance, electric start, 4 stroke production engine with similar power to a 125 2 stroke.
Having said all that, I recently became aware of an EX250 project that is already completed and that is currently being tuned. From what I have heard, the project seems like a success.
Danny |
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Alan Sheidler
Joined: 09 Aug 2001
Posts: 471
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| Posted: Wed Nov 23, 2005 9:23 pm Post subject: |
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| Danny Lerner wrote: |
The simple matter of fact, is that, 2 stroke motors are fussy. They don't like to start half the time, they want you to carry a change of jets along, they are annoying to mix fuel for, they smoke, they won't idle, they have terrible reliability, the list goes on...
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That has not been my experience at all. Mine always starts easily, jetting is not a big issue or a constant need at every site. Adding 4 ounces per gallon is easy, my engine will idle for hours, and the smoke is not much unless your jetting is WAY off. I've never stuck, blown up, or had any engine issues at all, except for a rain event where I had to drive through a lake and the ignition coil packed it in.
| Quote: |
Basically, I want a cheap, low maintenance, electric start, 4 stroke production engine with similar power to a 125 2 stroke.
Having said all that, I recently became aware of an EX250 project that is already completed and that is currently being tuned. From what I have heard, the project seems like a success.
Danny |
Again... seb@scca.com, with facts, figures, hp numbers, weights, etc....
Alan |
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Danny Lerner
Joined: 08 May 2005
Posts: 188
Location: United States, New York,
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| Posted: Wed Nov 23, 2005 9:45 pm Post subject: |
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Alan, I appreciate both of your posts. I do agree that the rules are there for good reasons  . But, that doesn't mean I have to be happy  . I am going to wait to see how my friend's project turns out, and may then petition the scca to include the engine. I will use his specs to give to the scca before I invest. In the meantime, I guess I will live with my cr80 shifter. If the ninja motor turns out to be a handful on a tight course, or I see myself not willing to go through another completely custom build project, I will probably go 125...
I do want to know though, how in the hell does your engine idle for hours? Mine won't idle for 5 mins... And, if it does by some miracle idle for a min or two, I can expect the plug to be fouled... The carb is not set rich, and I dont really want to lean out the mixture... (My jetting is good).
Also, when did you buy your motor? Wondering because if you bought a regular cr125 package - what year, and 5 or 6 speed.
Also, how often do you clean out the power valves? Do you feel you gain an advantage over a stock cr125 autoxing with the power valves, or are they dead weight because the pipe does not allow them to properly "tune"?
Danny |
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Ted Long
Joined: 08 Nov 2005
Posts: 29
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| Posted: Thu Nov 24, 2005 12:52 am Post subject: |
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| Alan Sheidler wrote: | | Danny Lerner wrote: |
The simple matter of fact, is that, 2 stroke motors are fussy. They don't like to start half the time, they want you to carry a change of jets along, they are annoying to mix fuel for, they smoke, they won't idle, they have terrible reliability, the list goes on...
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That has not been my experience at all. Mine always starts easily, jetting is not a big issue or a constant need at every site. Adding 4 ounces per gallon is easy, my engine will idle for hours, and the smoke is not much unless your jetting is WAY off. I've never stuck, blown up, or had any engine issues at all, except for a rain event where I had to drive through a lake and the ignition coil packed it in.
| Quote: |
Basically, I want a cheap, low maintenance, electric start, 4 stroke production engine with similar power to a 125 2 stroke.
Having said all that, I recently became aware of an EX250 project that is already completed and that is currently being tuned. From what I have heard, the project seems like a success.
Danny |
Again... seb@scca.com, with facts, figures, hp numbers, weights, etc....
Alan |
I agree, i love ours for their reliability and lack of "fussyness". If your worried about rejetting bolt on a set of pumper carbs from a snomobile! They don't have conventional jets, just screws and you can adjust them on the fly. The only thing in that string of pre-requisites you listed that our 2 stroke twins DON'T have is electric start. And we make more HP's.
Think about the battery and all that stuff that will be dead weight.
Do you have pics of this kart thats already built? I'de love to see how they put the package together. |
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Danny Lerner
Joined: 08 May 2005
Posts: 188
Location: United States, New York,
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| Posted: Thu Nov 24, 2005 10:38 am Post subject: |
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I dont have a picture of the built 250 kart. I am waiting for it myself. When the pics get sent, I will ask the owner if it is ok to post them. I'm not sure if he wants to "publicize" yet.
BTW, that twin looks pretty nice, but just a tad out of my skill level.
Danny |
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Chris Livengood
Joined: 24 Jul 2001
Posts: 2432
Location: United States, Pennsylvania, Da Burgh
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Alan Sheidler
Joined: 09 Aug 2001
Posts: 471
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| Posted: Fri Nov 25, 2005 11:03 pm Post subject: |
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| Danny Lerner wrote: |
I do want to know though, how in the hell does your engine idle for hours? Mine won't idle for 5 mins... And, if it does by some miracle idle for a min or two, I can expect the plug to be fouled... The carb is not set rich, and I dont really want to lean out the mixture... (My jetting is good).
Also, when did you buy your motor? Wondering because if you bought a regular cr125 package - what year, and 5 or 6 speed.
Also, how often do you clean out the power valves? Do you feel you gain an advantage over a stock cr125 autoxing with the power valves, or are they dead weight because the pipe does not allow them to properly "tune"?
Danny |
That is how Honda designed it.... I run the original 36mm carb, and original (factory installed) pilot jet. That is why it idles. I have tuned for torque, not HP. I am using a V-Force reeds setup, and a reed block spacer as well. The engine is a '96, (6-speed) which I found online via a karting classified section December of '99. It had never been run, a part of a stillborn homebuilt shifter kart project. First fire was in Florida for the Ft. Myers pro February 2000.
I took out the kick start system when I first put in a piston, Spring 2003. At that time I also changed the clutch, and cleaned the power valves. I also blended the exhaust port to match the Atomic 22 o-ring flange I run.
The engine did not see much use in 2003. I did not compete a lot in '04, and used another ($) motor for Nationals those two years. Before spring, I'll change the piston and ring for the second time.
I did experiment with pipes a couple of times. I even tried an aftermarket Motocross pipe. The rusults were mixed, and I have stuck with the RCE T3 pipe that I got when I first started. One dirt bike silencer produced a power band that was "unboggable" as I called it, since the engine had so much low end grunt with it installed. But the top end was off considerably, and lap times at a track I practice at were decidedly slower.
I have driven engines without the power valves which were peaky as hell. I have also driven engines without them which had a very broad power band. How much mine contribute to drivability for my use is a good question. I may experiment and find out; I just bought a set of p-valve plugs. One thing is for sure, if I make a mistake and miss a downshift, my engine does not leave me dead in the water on corner exit as I have had it set up for the last 5 years.
Alan |
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Ted Long
Joined: 08 Nov 2005
Posts: 29
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| Posted: Sat Nov 26, 2005 12:41 pm Post subject: |
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| Danny Lerner wrote: | I dont have a picture of the built 250 kart. I am waiting for it myself. When the pics get sent, I will ask the owner if it is ok to post them. I'm not sure if he wants to "publicize" yet.
BTW, that twin looks pretty nice, but just a tad out of my skill level.
Danny |
I would be hesitant to send out new pics of anything right away, i guess we'll see!
Yeah, our twins were long in the making, going from Yamaha rd-350 air cooled to td-250 (pre tz)air cooled. We finally decided the RZ-350 would be the best bang for the buck and they are plentiful in the junk yards where my folks live. We shortened the crankshaft about an inch and a half to keep it from drilling into my leg again, and we use a pvl ignition meant for an rd-350. We make around 72-75 hp with very minimal clean-up on the ports and v-force reeds with 32mm mikini bike carbs. The pipes are toomy t5's that my dad cut up and modified to fit. We could run a whole season without touching the motor, and it will sit there and idle for as long as you want it to. We hav'nt had any problems fouling plugs or anything like that either.
The one thing we're working on right now is trying to get a small YPVS controller, we're running with them wide open all the time, which is a bit peaky in some situations, but you learn to use it well. The motor has so much torque that it can pull you out of any situation without a problem even without power valves. If we can get the power valves to work right  ......sheesh, its already a tire shredding machine.......! They are a handful at first, but we've got some time in them now and its all about tweaking them and figuring out what they like. |
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Danny Lerner
Joined: 08 May 2005
Posts: 188
Location: United States, New York,
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| Posted: Wed Nov 30, 2005 6:01 pm Post subject: |
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I was ok'ed on the pictures. The yellow one with the EX250 is the kart I am deciding to build or not. As it happens, this particular ex250 kart is very well done, and has turned lap times VERY similar if not faster than a cr125. The questions are, is that doable on an auto-x course? AND, also would it be possible to mount on a 125 shifter chassis to keep weight down?
The other two karts currently call my garage home.
http://community.webshots.com/user/gto7419
Danny |
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Ted Long
Joined: 08 Nov 2005
Posts: 29
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| Posted: Thu Dec 01, 2005 12:43 am Post subject: |
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HOLY CRAP that motor is huge! I thought ours were big! I dunno if you could fit that on a 125 chassis without moving the driver over a good 3 inches. You would have to move the tank over too (not a big deal) and the pedals could stay the same, but man, that thing could put the hurt on you if you wadded it up and it came loose. It looks really tall too which would make me wonder about the change in center of gravity. Would a 125 have a tendency to come up on two wheels more with a motor that tall? It seems like it might get in your way alot too(on a 125). Wow.
I 'll give it to you're friend, he did an execllent job with the overall package, but was it worth it? |
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