4 stroke vs 2 smoker?

what 2 stroke with pipe and jackshaft is cheaper than what 4 stroke? what are you comparing? every time i look at everything i need to run a 2 stroke i find the 4 stroke is far less. and there is more competition running 4 cycle as well. if a Yamaha was the same price as a clone with longer race intervals between rebuilds and cheaper rebuilds everyone would be racing them.
Used BLUEPRINTED KT-100 $500.......j/s from BMIKarts.com - $200.....used pipe -- $100....Used 2 disc clutch -- $150....total: ~$1000. Will run circles around a clone, predator, and most animals. Rebuild 1x season - $300. I don't know where you're looking, but must not be the right places... :)
As to why more aren't racing them? Good question...they're cheaper AND faster, so a no brainer for me. :) Also, more speed reveals weaknesses more...ppl don't want to admit they aren't willing to do the work to win, so we have 30 classes with 20 weights and time trials instead of heats, consis, elims, and features...
May castor fumes never go away....
 
Used BLUEPRINTED KT-100 $500.......j/s from BMIKarts.com - $200.....used pipe -- $100....Used 2 disc clutch -- $150....total: ~$1000. Will run circles around a clone, predator, and most animals. Rebuild 1x season - $300. I don't know where you're looking, but must not be the right places... :)
As to why more aren't racing them? Good question...they're cheaper AND faster, so a no brainer for me. :) Also, more speed reveals weaknesses more...ppl don't want to admit they aren't willing to do the work to win, so we have 30 classes with 20 weights and time trials instead of heats, consis, elims, and features...
May castor fumes never go away....
You forgot about the motor mount, electric starter, Jack shaft, pipe cradle for the bumper and a qt of two cycle oil. Brand new national level clone with pipe and chain guard included is 1200. And there are lots of people to race against. Again brand new vs used crap shoot warn out junk. And no one to race you left out a bunch of stuff. I wish we ran Yamahas I would prefer a real racing engine vs a reworked tiller. Again no one to race against to shell out even 1000.
 
Haa ha this is like a ratio is a ratio lots of fun . Lots of factual opinions.
1200 dollar clone dont come with a motor mount either :) .
Took me along time to convince
The driver to run a kt . After that it was on . 3 kt's a parrilla and a wet 116 parilla hybrid .
If pay and play is the Goal .
A new clone is cheaper to start
From scratch .
 
Haa ha this is like a ratio is a ratio lots of fun . Lots of factual opinions.
1200 dollar clone dont come with a motor mount either :) .
Took me along time to convince
The driver to run a kt . After that it was on . 3 kt's a parrilla and a wet 116 parilla hybrid .
If pay and play is the Goal .
A new clone is cheaper to start
From scratch .
ok
215-335 dollars for the jackshaft motor mount (this price does to include driver pully) or 60-85 clone mount.
any way you want to slice it the math always comes out with the 4 stroke on top. and ill keep sayin nobody to race against
don't say its cheaper! you are lying to yourself
https://www.facebook.com/marketplac...wse_serp:7274b11d-9af7-4a0b-9b08-cbb964fd8443
^^^^ they come with one free refresh. LOL
 
ok
215-335 dollars for the jackshaft motor mount (this price does to include driver pully) or 60-85 clone mount.
any way you want to slice it the math always comes out with the 4 stroke on top. and ill keep sayin nobody to race against
don't say its cheaper! you are lying to yourself
https://www.facebook.com/marketplace/item/230294932779904/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp:7274b11d-9af7-4a0b-9b08-cbb964fd8443
^^^^ they come with one free refresh. LOL
Reed Jet 825.00 jackshaft 200.00 clutch 250.00 I already had a pipe = 1275.00 and will beat any clone ect.
 
The OP didn't ask what to buy, just opinions on which is faster. Again, it depends on what kind of track you race on. Again they make similar lap times when by themselves and the 2 strokes do not like their momentum interrupted. To some degree the same can be said about 4 strokes but 2 strokes take longer to recover than they do.
 
Doesn’t matter how fast it is when you’re the only one on the track. Best to pick the package with the bigger classes IMO.
 
You can't beat cubic inches but if all things are equal then it's spin it to win it which puts the 2 stroke on top.
 
The OP didn't ask what to buy, just opinions on which is faster. Again, it depends on what kind of track you race on. Again they make similar lap times when by themselves and the 2 strokes do not like their momentum interrupted. To some degree the same can be said about 4 strokes but 2 strokes take longer to recover than they do.

I think the way I would approach this is...

(disclaimer: hypothetical example follows)

Let's say a track in question has a minimum speed of say... 35mph, and a max speed of 55mph.

Pick the gear ratio that puts the revs for both the 4-stroke and the 2-stroke in their "sweet spot" (more like "sweet range") -- and now the rev range that each engine will be using is known.

Dyno the engines, and see which setup has the most "area under the curve" within that rev range. I realize this won't provide a black and white answer on which engine will be faster around the race track ... there could be all sorts of nuances that could/would "sway" this in favor of one or the other (a big one would probably be simply whether a 4-stroke or a 2-stroke puts the power down better on the first hit of the throttle).

But this (area under curve) may at least give an indication of which setup has the "potential" to be faster.

.... or not. :unsure:

PM
 
look at lap times on race monitor is the easiest way. you will need to know who the drivers are. I've seen people on high hp two strokes do equal lap times to predators. Ill ask Barrett Terry next time I see him. he was/is successful at stock, limited and open 4 strokes as well as the king of Yamaha and open 2 cycle.
 
Fart knockers! Haha. Here in Oregon it’s sprint for me. The 2 smokers r faster for sure. There a quality race engine compared to a lawn mower. I like the modified Briggs 206. It’s a nice rabbit hole to go down. It would b a pleasure to c highly modified 9500 rpm 4 stroke run at my track. it’s been a lot of fun these last to years trying to figure out what it wants to run better. I just enjoy telling people I have a lawn mower that revs to 8500. im studying methanol fuel and hope to try it this year. To tell people I have a lawn mower that revs to 8500 on moon shine would b sweet.
 
You might want to consider rebuild cost. A lot more moving pieces in the 4 stroke.
I got my used lo206 for 400. And in no time found a 50 dollar wf coil 7000 rpm. Some one gave me a used wf cam. I got valve springs from Dyno cams. And couldn,t waite to cut the seal off it. I’m so glad I went down the modified road. It’s way faster then the spec lo206, wf, and a few clone, predators in my area. The 2nd year I spent 400 to rebuild it. This year I’m into it 550. It will b I great hobby till it hurts to much to drive this kart.
 
So the question is mainly...why are people spending so much money on slow stuff when they can spend the same amount and go maybe 2 seconds a lap faster? Are they just followers?
 
So the question is mainly...why are people spending so much money on slow stuff when they can spend the same amount and go maybe 2 seconds a lap faster? Are they just followers?
Basically, it is most started in a lower cost to get started, to see if they liked it.
So initial investment was less.
Then, parts and tools were accumulated for the low cost setup. Knowledge also accumulates.

Now, the time and money required to sell all, and make that step to higher power makes it much less attractive.

Also, if no one races that higher power class in your area, there is another investment. Travel time and costs.

Maybe they just like racing where driver and setup make more of a difference.
 
So the question is mainly...why are people spending so much money on slow stuff when they can spend the same amount and go maybe 2 seconds a lap faster? Are they just followers?
What people are you talking about that are spending loads of money to go slow? Are you referring to dirt oval clone racers or sprint track 206 racers?
 

not even funny what this animal does to those ring dings . im sure its an open but those 2 cycles are built too
The motor Evan is running in this video from 2016 is a 100cc Controlled Stock Reedjet on alky. (stock port, WKA Controlled engine) This was Evans first time in anything bigger than a blue plate Jr Clone. He was sent to the rear of the feature because we went out without a transponder and had to stop to get one after he entered the track.
That being said, the power between a 14.5 OHV Open and a Stock Reedjet are pretty much on par. Close to equal HP and more torque on the OHV. Evan and Kenny Buff were pretty much equal in lap times in the feature. Both karts were at 380 lbs.
Currently the OHV is favored with advancements in billet blocks, heads and titanium valves where as the air cooled 2-strokes are decades old with no advancements. The biggest disadvantage now is in the Junior UAS rules which allow a fully built billet 14.5 OHV to compete against 100cc Piston Ports with single carbs and a max to 120cc. The issue is the 14.5 OHV motors have the ability to be in the 40 plus HP range with lots of torque, the availability of billet and titanium components versus Piston Port motors that are difficult to find ( with the exception of the KT100) and parts availability are very hard to come by. Bullers best 120cc Yamaha with custom stroker crank, updated ports and liner and custom pistons are 4 grand and forget getting one within a year. This motor would be on par with a 14.5 OHV. The Italian 100cc JICA Piston Ports are nearly extinct stateside. My suggestion when the rules come up for review in the JR UAS is to allow 100cc REED motors up to 120cc and any carb. This would at least allow for more parts availability and hopefully increase entries.
 
You people realize that this subject has been argued for over 50 years. There are people that like the 'Fart Knockers' and there are people that like the 'Peanut Shellers' and nothing you can say will change their minds. As far as which one is faster, it's really very simple. The one that has the smartest engine builder..... I have been racing for over 60 years and I have seen both engines dominate on different occasions at many national events. It's not the engine, It's the entire package. If you want your kart to go faster, I'll give you a speed tip. Work on it......

You people are beating a dead horse.......
 
The motor Evan is running in this video from 2016 is a 100cc Controlled Stock Reedjet on alky. (stock port, WKA Controlled engine) This was Evans first time in anything bigger than a blue plate Jr Clone. He was sent to the rear of the feature because we went out without a transponder and had to stop to get one after he entered the track.
That being said, the power between a 14.5 OHV Open and a Stock Reedjet are pretty much on par. Close to equal HP and more torque on the OHV. Evan and Kenny Buff were pretty much equal in lap times in the feature. Both karts were at 380 lbs.
Currently the OHV is favored with advancements in billet blocks, heads and titanium valves where as the air cooled 2-strokes are decades old with no advancements. The biggest disadvantage now is in the Junior UAS rules which allow a fully built billet 14.5 OHV to compete against 100cc Piston Ports with single carbs and a max to 120cc. The issue is the 14.5 OHV motors have the ability to be in the 40 plus HP range with lots of torque, the availability of billet and titanium components versus Piston Port motors that are difficult to find ( with the exception of the KT100) and parts availability are very hard to come by. Bullers best 120cc Yamaha with custom stroker crank, updated ports and liner and custom pistons are 4 grand and forget getting one within a year. This motor would be on par with a 14.5 OHV. The Italian 100cc JICA Piston Ports are nearly extinct stateside. My suggestion when the rules come up for review in the JR UAS is to allow 100cc REED motors up to 120cc and any carb. This would at least allow for more parts availability and hopefully increase entries.
Chris, the original intent was to run limited mods against a stock appearing kt with a max bore of 110cc. This would have been fairly even performance wise and budget friendly. Plenty fast enough to be a stepping stone for the Juniors. The discussion about what should and shouldn’t be allowed was an open dialogue consisting mainly of people with zero intent to run. The rules quickly blew up to a 14.5 billet 4 cycle vs an open piston port… and still pushing for reed engines then because of course, there are advantages and disadvantages to both sides. The 4cycle drives like a lazy boy and has plenty of tourque to make up for a shotty setup. The open jica requires a bit more nerve to drive and has a more narrow setup window, but wound up over 15000 with bite in the track they’re lightning quick. Personally, I don’t think that 2-4000 dollar engine packages are what’s needed to get kids participating in this class.
 
While I do agree that the engines prices are a concern. But, it's the UAS, so price point is sort of out the window.
But, at the same time allowing 85-100CC reed engines would then put them relatively back on the cheaper side of things. The cases and jackshaft setup for an 85-100cc MX engine could easily fall within that price frame after pipe and everything. So it's still pricey, but I agree with Chris that the Reed engines are the answer for the availability of piston port engines, and they would more closely compare to current technology in OHV four strokes.

(Edit) I should make it clear this is more in terms of Jr UAS, NOT so much the class being discussed here persey.
 
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