300 TPI Fuel

[Sowa]

All, I'm looking at getting an RK Tek head insert for a snowbike setup. In an effort to get as much out of the bike I'm thinking of running a higher octane fuel and increasing the compression.

I called VP and they recommended T4 for the TPI bikes in a snowbike setup.

Has anyone had any luck with other fuels?

 

[portgrinder]

All, I'm looking at getting an RK Tek head insert for a snowbike setup. In an effort to get as much out of the bike I'm thinking of running a higher octane fuel and increasing the compression.

I called VP and they recommended T4 for the TPI bikes in a snowbike setup.

Has anyone had any luck with other fuels?

Run what fuel the head mfg tells you. Compression makes the power. Octane allows your motor to stay alive @ increased compression

 

[Sowa]

I spoke with the gents at RK Tek on the phone. Was told to reach out to the fuel suppliers for snowbike fuel recommendations. Head mfg didn't have any input on which fuel to run for this application.

 

[Sheetmetalfab]

I spoke with the gents at RK Tek on the phone. Was told to reach out to the fuel suppliers for snowbike fuel recommendations. Head mfg didn't have any input on which fuel to run for this application.

That’s because they don’t test their products…..

Kelsey has been selling snake oil for many many years.

i did 2 rounds with his products and won’t touch that disaster again.

 

[Sowa]

What did you end up with?

 

[capulin overdrive]

Slaven's knows altitude and snowbikes, talk to them.

 

[wwillf01]

Now for our yz250 we have been very happy with Rk Tek head… I know t2 (premix version) really wakes the bike up…. It expensive though for snow biking and the amount of fuel you run through? But if money is burning in the pocket you do feel the difference…. At high altitude you really have to pump up the compression pretty high to warrant it.


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[eric82930]

I've seen twice the rk tech heads are too high compression for the thin base gaskets most bikes seem to end up with after a rebuild. The best rk head builds I've done actually used 2 base gaskets which raised the ports but the compression was still plenty. It was not on a snow bike though. I don't have any tpi experience in snow but the ports on the 300 are way too low for peak power so if your series enough to run race fuel, I would also port the exhaust or raise the cylinder with gaskets the get the comp back with a super hc head.

 

[CB-BLR]

Now for our yz250 we have been very happy with Rk Tek head… I know t2 (premix version) really wakes the bike up…. It expensive though for snow biking and the amount of fuel you run through? But if money is burning in the pocket you do feel the difference…. At high altitude you really have to pump up the compression pretty high to warrant it.


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I have heard others say that the two stroke snow-bikes go through a lot more fuel than say a 450 or 500...Has that been your experience?

Chris

 

[wwillf01]

100 percent the yz250 will down 5 gallons for every 3 or so on the 450… the yz is at a constant pin it to win it state .. I compare it to a 125 on dirt a blast to ride but for sure you need to be way more aggressive or lighter .. I have used u4.4 on the 4 stroke it was good for 2 hp on the dyno when tuned and mapped for it … the 2 stroke t2 gives it the same kick in the pants feel but here in utah you would burn through a lot… at 10 or more a gallon it gets pricy .


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[portgrinder]

I spoke with the gents at RK Tek on the phone. Was told to reach out to the fuel suppliers for snowbike fuel recommendations. Head mfg didn't have any input on which fuel to run for this application.

that is absolutely ridiculous. I would return it. 100% would not run it.

 

[portgrinder]

I have heard others say that the two stroke snow-bikes go through a lot more fuel than say a 450 or 500...Has that been your experience?

Chris

mine is pretty even with the 450s I run with. Maybe a smidge more. Also making more power than them tho. ?

 

[CB-BLR]

mine is pretty even with the 450s I run with. Maybe a smidge more. Also making more power than them tho. [emoji14]

What kind of hp and torque are you making? And at what rpm?

Thinking of playing with a 300 tpi after tweeking on my 550.


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[portgrinder]

What kind of hp and torque are you making? And at what rpm?

Thinking of playing with a 300 tpi after tweeking on my 550.


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67 or so. Tq almost as flat as a 4 stroke. Big long thread on here somewhere. You can see the numbers on the screen on the wall. Stock was mid 40’s I think. Been awhile.

Quick vid

 

[CB-BLR]

That is impressive!

You have a crank Dyno?


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[Sowa]

67 or so. Tq almost as flat as a 4 stroke. Big long thread on here somewhere. You can see the numbers on the screen on the wall. Stock was mid 40’s I think. Been awhile.

Quick vid

So if I followed the other thread correctly, the hot ticket is:

2mm raised cylinder
red spring (1.5 turns in)
Cut cylinder head for a 15:1 compression ratio
VP C12 Fuel
NPP Pipe