It's not how much power, but how it is delivered, the 300 has every bit as hp as the 450's by rating and the 300 delivers it so linear it is deceptive how much it is doing because you don't feel the big "hit" of power, the exhaust port is way down there; the 500 2stroke on the other hand is rated quite a bit higher hp (70-80plus). In the woods over rocks and roots etc. is where that linear power delivery is so effective along with the suspension, lightweight.. Even in a drag on the asphalt will surprise you how well the 300 will do by the time you reach the finish line. That said I would like to try a AF 500 stroke in the snow.
Lets talk ktm 300 xc
- Thread starter relentless rider
- Start date
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portgrinder
Well-known member
Good read here for sure. A few things I'll throw my 2 cents in on
You'd never believe it by my engine builder did the same test on oil and pretty sure he told me 16:1 was the best. Repeatable results for sure. Oil = hp
A quick note on RPMS 4 vs 2 stroke. You can't really just compare them straight up. Piston speed is your limiting factor from things flying apart lots of times. Longer stroke means your piston max speed is higher for a given rpm. 4 stroke pistons just "wiggle" up and down. It's all bore. Whereas 2 cycles are somewhere around square (bore=stroke)
That's the same reason you can rev a 125 to the moon and a 1200cc twin usually isn't much past 8k
I really like the PC pipe. Dyno tested a bunch on my yz250. The PC platinum two made 3 horse on pretty much the entire rev range. Cutting 25 thou off the head got another two. Boysen rad valve really sharpens up the bottom.
You'd never believe it by my engine builder did the same test on oil and pretty sure he told me 16:1 was the best. Repeatable results for sure. Oil = hp
A quick note on RPMS 4 vs 2 stroke. You can't really just compare them straight up. Piston speed is your limiting factor from things flying apart lots of times. Longer stroke means your piston max speed is higher for a given rpm. 4 stroke pistons just "wiggle" up and down. It's all bore. Whereas 2 cycles are somewhere around square (bore=stroke)
That's the same reason you can rev a 125 to the moon and a 1200cc twin usually isn't much past 8k
I really like the PC pipe. Dyno tested a bunch on my yz250. The PC platinum two made 3 horse on pretty much the entire rev range. Cutting 25 thou off the head got another two. Boysen rad valve really sharpens up the bottom.
The pipe is subjective ! It really depends on the model of bike.
For instance on the CR500 the FMF gnarly is way better than every other pipe out there except the FMF Fatty lol (dyno proven by Millar Racing).
On the 300 i have a PC2. Its a pile pile of junk ! The fit was the first issue. PC had to send me two pipes because it never fit right. Finally fit it and then... I thought the power was good......
Until i rode a identical 300 with a FMF gnarly. It not only sounded better but ran and had more power than my PC2.
On top of that i hit it one time and it folded over like a piece of tin foil. This is a PC2, not a first gen !
My PC2 is gone ! If anyone wants a Pirie P2 carbon pipe guard for a PC2 (best pipe guard built PERIOD, eline and all other brands don't compare) let me know an i will sell you one ! I don't think they even make them for the PC2 anymore !
FMF is the only pipe i will buy for the KTM 300 !
The Boysen RAD valve for my 500 is ok, but Millars other valves are much better than the RAD !
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mtn-doo
Well-known member
The RPM point is something a lot of people don't realize. You often hear about a 2 stroke. "I have to rev the sh%t out of it". People don't realize the 450F actually rev's much higher than the 2 stroke 250, 300,. The 300 for example flattens out just over 8K RPM. That's not very high at all. The 500's in the high 6's not over 7K. Very low. They are deceiving when you listen to them. The thumpers have been all everyone knows and some good old 2 stroke knowledge has been lost, or never learned. If a 2 stroke and a 4 stroke were cruising side by side at 6K RPM. "everyone" would swear the 2 stroke is revving "much higher". It isn't. The 2 stroke is firing and getting a "power stroke" with every stroke, the 4 stroke on "every other". That makes the 2 stroke sound like it's revving higher, but it's not. They are both at 6k. A 300, WOT breaking trail in the deep is stabilized under 8K. A 450F is bouncing off the rev limiter at 10.5 or higher!
Let the little honey sing! You won't hurt it.
Let the little honey sing! You won't hurt it.
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snowboatboy
New member
Summitboy you got a web site for Millar racing? tried to find them on google, but couldn't.
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relentless rider
Well-known member
Well I just ordered the apt smartcarb! Cant wait to be done jetting the 300, hopefully ill see it before snow hits.im hoping the fuel will last longer too, ive been sucking down a tank in 40 miles
http://www.millarengines.com/About.page
Ask for Adam ! Tell him Chris sent you. He is the best. Knowledgable and gives you support like no other way after the sale. He has built some crazy 500 motors. Some rev to 11-12,000rpm lol. Thats the special service lol
When you say 40 miles are you talking on the snow ? Or singletrack ?
Ask for Adam ! Tell him Chris sent you. He is the best. Knowledgable and gives you support like no other way after the sale. He has built some crazy 500 motors. Some rev to 11-12,000rpm lol. Thats the special service lol
When you say 40 miles are you talking on the snow ? Or singletrack ?
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relentless rider
Well-known member
Single track , and hill climbs, but im nearly out of fuel when my friends ktm 500 is at a half tank .I cant say 40 miles I guess cuz I dont have a speedo just going off of his.i ride from 3600 to 7800 on a loop trail , im no jetting expert ether lol just running 36 plot 162 main and the needle was stock,2 turns out on air srew. So the apt will be awesome.
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relentless rider
Well-known member
How much fuel are you burning in the snow on the 500.? That was one of my worrys with the 300 the way I was using fuel on dirt id never be able to pack the gas for snow,
Wow. Your 300 burns a ton of fuel ?? I just did 90km of single track and i still had a pile of fuel left. Do you have spooge on your silenecer ?? My 300 has aleays been way better on fuel than my 450 was. Id go riding my 450 with all the 300's and i would be empty way before them. Weird. Where is your needle set ? I cant wait to try a Smarty on my 300 !
I have not had the 500 on the snow yet. Will be interesting to see what it burns. I
was surprised in the sand on a day ride it used less fuel than i thought it would and i was on then pipe a lot LOL !
I have not had the 500 on the snow yet. Will be interesting to see what it burns. I
was surprised in the sand on a day ride it used less fuel than i thought it would and i was on then pipe a lot LOL !
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mtn-doo
Well-known member
I ran a 40MM Billet Smart carb on the "KX500 Monster". It had the 250F gas tank, 1.6 gal, "tiny" and my 3.3 on the back. Ran all day and came home with gas left over. The Smart Carb is super efficient. A 38MM on a KTM300, metering rod correctly set should run for ever. Their test's are 30% more efficient than EFI. You will burn less gas than your buddies.
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relentless rider
Well-known member
I think I was losing alot of fuel because of the float bowl over flow my skid plate was always wet, and id look down and it would be dripping every time id put the kick stand down , not much for spooge , and was always crisp unless im going slow and lug n around in 3 rd for a long time than it would start loading up , hopefully thats a thing of the past now
anyone want a stock 300 carb...? Ill sell it cheap lol
anyone want a stock 300 carb...? Ill sell it cheap lol
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relentless rider
Well-known member
Mtn-doo , did you order the 38 cast apt carb for the 300 project ? How long of a wait for the pre order? Anyone know?
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mtn-doo
Well-known member
Wow, I will be watching for it. The YZ325 would also be an excellent choice. I will post the info on "who's riding a 2-stroke thread". Very impressive
