anybody considered swapping in a 4 stroke?

[Scott Nagler]

With the new 4 strokes like the Yamaha WR250 rapping out at 13k and plenty of stock power and more to be had through exhaust mods n other little things. I've thought about swapping one in as it would still be legal for F125, could get into the 30+hp range easily, elec start, 4 stroke quietness, and I can only assume its got broader hp thus ideal for autox. Anybody else look into this yet? I'm already a light driver so a little extra weight is inevidible.
_________________
Still a noob, but can't wait to be "on the pipe"

[Larry MacLeod]

[Scott Nagler]

actually I have read the rules, thus why I mentioned it. You can use up to a 250cc 4 stroke, no limitations on elec start, can't have a "gear box" and otherwise similar rules as a 2stroke. It still would have as much or more hp than my current 125cc, but be more linear with some slight peakiness still... titanium valves help there. It'd be nice n quiet too, I figured my gas savings would be good too. Rebuilding costs aren't as bad, and because the exhaust pipe isn't as critical you don't have to worry about the industry dropping them off the list of motors to support.
_________________
Still a noob, but can't wait to be "on the pipe"

[Brian Garfield]

I'm confused, you said you read the rules, and say there's no 4 Stroke gearbox motors allowed, but suggest the WR250. Isn't that a shifter?? No 250 4 Stroke shifters allowed...right?

Brian

[Vernon Head]

Brian is correct:

3. Other Engines: Engines must be either a) mass produced
single cylinder two-stroke engines not to exceed 125cc or b)
mass produced single or twin cylinder, four-stroke engines
not to exceed 250cc of total displacement. No prototype, preproduction,
“works type” motors or road race engines are
allowed. Shifter or gear-box type motors are prohibited. Karts
with engines under this specification must run at a minimum
weight of 360 lbs. Exception: the engine must not appear on
the following list, which may be altered at any time by the
SEB upon notification of membership: No engines are currently
listed

[Brad Linkus]

We are the importers of all three 250cc 4-stroke engines you can use. Vampire, Biland, Oral. We can supply you with what you need. Engines 4 Racing, 303-833-0474, imimotorsports@hotmail.com

Brad Linkus

[Kristian Werkley]

Has anyone tried using the current crop of 250 4 stroke MX motors, or try to have them homologated for moto classes?

[Vernon Head]

Not that I know of. You can ask your local region to allow it, since it should be about the same performance as the current formula. Or, you can write to SCCA Solo Events Board and ask them to add this to the list of allowed motors. If enough people show interest, they will give it more serious consideration.

The future of karting in general is, in my opinion, probably headed towards 4-strokes because of the pollution. At least that's what I've been reading. Nobody knows how long this will take. I would guess 3-5 years. It's already happening in Motocross, and the manufacturers are no longer developing the 2-stroke technology (also my opinion).

[Kristian Werkley]

Yea I definitely agree with all of that.

I think it could probably be an advantage just as it has been in motocross, firing the thing up would probably become more painful though.

I imagine it wouldn't be terribley hard to get the SCCA to come around, but I was thinking more interms of what it takes the likes of WKA, CIK, or some of the others to homologate engines.

[Scott Nagler]

well now I'm confused... I thought I understood that it could have the same tranny config as a 125cc. Wouldn't make any sense to not allow a 4stroke to have a 5 or 6spd tranny like the 125's do. In motox they are allowed to, so I can only assume that you can in karting too?

"Shifter or gear-box type motors are prohibited" I understood this to be a generic statement for the karts and not specifically attributed to 4 strokes since the 125cc was also mentioned in this section. If they can put ICC 125's with tranny's then they can do the same with 4strokes. I understood shifter/gearbox to be some sort of specialized tranny other than the normal motox tranny... like a paddle shifter or what not, and something that would allow LSD. I don't recall seeing the 360lb, always thought 385 for F125 no matter what. If doesn't get to have a tranny then its not F125, its Jr Kart.
_________________
Still a noob, but can't wait to be "on the pipe"

[Scott Nagler]

[Christian Hubbell]

[Scott Nagler]

lol, just found it... guess I'm wrong... I sure didn't read it that way when I first read it... I mean how could you prohibit a tranny'd motor in a class full of em... seems like BS to me. I'm gonna see if I can get them to make a specific 4stroke section like they did for the ICC's. 4 stroke not exceeding 250cc and be of MotoX origins..... cam changes allowed or not allowed... etc. We need to get some more interesting competition and I think the world is going 4 stroke anyways so why not go with it? Maybe make a 4 stroke class all together
_________________
Still a noob, but can't wait to be "on the pipe"

[Vernon Head]

I need to take back what I said earlier about asking your local region for a 250 4-stroke gearbox class. Can't do it for insurance reasons. 125cc is the largest gearbox engine allowed in SCCA Solo karts.

[Scott Nagler]

really?? that is interesting, hadn't even thought about that... would it just be too wicked of a setup or something? If its geared for 70mph and makes 30hp, I don't see how thats soo diff from 125cc 2strk
_________________
Still a noob, but can't wait to be "on the pipe"