Any 2 stroke TPI 250 or 300 builds out there?

[byeatts]

Yeah, I'm a 2s fan but, the only bike that has ever run out of fuel on one of our rides was a two stroke. I don't remember how much fuel he used but it was considerably more than 4s. Granted it was older with carb bike.

Yep I love xc 300 ride it all summer however it will Not hang with the 450sx in the snow , The 300 is 44 HP at 8500 rpm.many ponies down from the 450 at full throttle and the moment rpms drop it is game over, lacks the torque to recover , As for the weight, The 2021 450SX is 224 lbs @ 53HP at 10500 rpm with a lower profile motor and the TPI 300 is 226 lbs , and the 2 stroke requires more fuel to carry adding and additional 6-12 lbs, both were dynode at same location at the rear wheel. So the weight savings everyone dreams of is not accurate, The 300 could not get up the same steep climbs 4 other 450,s easily made, It had to side hill around to meet up and after 5 attempts. The 300 rider thought is was the magic setup. but not any longer. the 450 will rev to the moon which translates to track speed by 10 mph, the 300 will not rev near that high, it had CDI , high compression head, reeds pipe ect. The 300 rules in the woods for summer , park it in the winter. Hang a 300 and 450 fueled and ready to hit the mountain and the new 450 is much lighter , The old daze of thinking the 450 are heavier are inaccurate.

 

[boondocker99]

Boondocker99, thanks for reply. So your saying the TE has the same tranny as the xc. My understanding is that the tranny in the xc has a higher 1st and slightly higher second and 3-6 are the same xc to exc, parts fiche shows 3-6 the same part as I recall, 2020 parts.

So you think you might prefer the exc tranny because of the lower 1st or is there something I'm missing? I'm partial to the lower 1st as that's what I have in my 500exc.

How about fuel consumptio? Any comparison to the 450 4s?

My understanding is that the Xc has a standard (short) and xcw has wide ratio. Xc should be better for a snow bike. I put 3.1gal tank on w/2.5gal on the tunnel and that lasts me a full day...

 

[byeatts]

My understanding is that the Xc has a standard (short) and xcw has wide ratio. Xc should be better for a snow bike. I put 3.1gal tank on w/2.5gal on the tunnel and that lasts me a full day...

the XC is a simi close ratio 6 speed , the XCW has very low 1 st gear, almost useless , slightly lower 2 and higher 3rd . 4,5,6 and the same on both bikes .the XCW has a big gap between 2 and 3rd, its not great even in the dirt .

 

[boondocker99]

Yep I love xc 300 ride it all summer however it will Not hang with the 450sx in the snow , The 300 is 44 HP at 8500 rpm.many ponies down from the 450 at full throttle and the moment rpms drop it is game over, lacks the torque to recover , As for the weight, The 2021 450SX is 224 lbs @ 53HP at 10500 rpm with a lower profile motor and the TPI 300 is 226 lbs , and the 2 stroke requires more fuel to carry adding and additional 6-12 lbs, both were dynode at same location at the rear wheel. So the weight savings everyone dreams of is not accurate, The 300 could not get up the same steep climbs 4 other 450,s easily made, It had to side hill around to meet up and after 5 attempts. The 300 rider thought is was the magic setup. but not any longer. the 450 will rev to the moon which translates to track speed by 10 mph, the 300 will not rev near that high, it had CDI , high compression head, reeds pipe ect. The 300 rules in the woods for summer , park it in the winter. Hang a 300 and 450 fueled and ready to hit the mountain and the new 450 is much lighter , The old daze of thinking the 450 are heavier are inaccurate.

300 "feels" 100lbs lighter and lower center of gravity....Also sounds like you are referring to a carb model seeing how there is no CDI ecu for a TPI yet. BIG difference on the snow at elevation! If nimbleness is important it’s a lot like comparing a turbo stroke sled to 800 NA 2 stroke. Different people have different preferences....

 

[byeatts]

300 "feels" 100lbs lighter and lower center of gravity....Also sounds like you are referring to a carb model seeing how there is no CDI ecu for a TPI yet. BIG difference on the snow at elevation! If nimbleness is important it’s a lot like comparing a turbo stroke sled to 800 NA 2 stroke. Different people have different preferences....

No the new 450,s have low center gravity, new lower cylinder head , the 300 all have Lectron carbs that actually out perform all the TPI bikes. I own the TPI as well , I own both 300,s and 450,s and is unbiassed accurate comparisons on the hill. the TPI has the GET ecu totally programable via I phone, I m not suggesting it sucks , I only suggest that it is not on par with a 450.

 

[portgrinder]

Ya there is some work to do stock vs stock for sure. Your numbers are the same as I’ve seen. Stock they are a long ways from a 450. A good pipe + carb + compression gets you into the mid 50’s

I would make a little resistor to fool the coolant temp sensor myself if the tpi bikes are that fussy.

 

[wwillf01]

The riders weight also is a big factor on whats going to work the best in my opinion...

Sent from my SM-F916U1 using Tapatalk

 

[byeatts]

Ya there is some work to do stock vs stock for sure. Your numbers are the same as I’ve seen. Stock they are a long ways from a 450. A good pipe + carb + compression gets you into the mid 50’s

I would make a little resistor to fool the coolant temp sensor myself if the tpi bikes are that fussy.

yes . Its all about RPM and track spin, The larger bores low rev motors are horrible on the snow, need to spin and the faster the better. Overrev is what separates the 450 from the 500 performance .

 

[boondocker99]

No the new 450,s have low center gravity, new lower cylinder head , the 300 all have Lectron carbs that actually out perform all the TPI bikes. I own the TPI as well , I own both 300,s and 450,s and is unbiassed accurate comparisons on the hill. the TPI has the GET ecu totally programable via I phone, I m not suggesting it sucks , I only suggest that it is not on par with a 450.

The difference in feel has little to do with the lower center of gravity but mostly all with the intertia of the rotation of the engine internals. I'm certain you know that but your feedback is very bias and you don't volunteer any info about the 2 stroke advantages. Furthermore it does not take much to get carb model out of tune at elevation which is what you are comparing to on the snow. The TPI is rated stock at 47HP and it's very easy to bump that up with high comp head and tune but again you wouldn't volunteer that info. I'm not saying a 450 won't out pull a 300 or that the 450 is not less forgiving on the power curve but in my case I just enjoy riding a 300 TPI way more than a 450. Again, as I stated above on the deep days I'm riding my Summit 850 as I just enjoy sledding more in the real deep fresh snow. If that ever changes I'll drop a BRC500 in to have all power I need and lightweight feel without the 4 stroke BS. To each his own, different people have different preferences. I've talked enough people who had 450 race bikes and went to the TPI for the reasons I'm stating plus no regular oil changes, expensive rebuilds, spaghetti values, etc . My guess is you probably owned a 4 stroke turbo in the day and felt it was the best thing snow at that time too... Not my cup of tea. I honestly almost didn't build a snowbike after riding 2 YZ 450s but convinced myself I could overcome that I didn't like about those snowbikes which resulted in a 300TPI w/CMX kit which I'm very happy with. So glad I was able to get the feedback I did about the 300s before I committed. There are simply pros and cons each way and the great thing about a snowbike is that you rarely need to go straight up big hills and for me lightweight feel over rules power in the trees.

 

[dooman92]

Maybe things have changed, I only checked for 2020 but, the only difference (according to part numbers) between the 300 xc and xc-w tranny is first gear. Both bikes have same parts for 2nd thru 6th. 1st is lower on xc-w so 1st to second would have different gap.

 

[eric82930]

I ride a xcw in dirt and the gap from first to second is rediculous. If you use it in snow plan to gear accordingly so first will probably be useless and slip clutch to keep 2nd from bogging out.
The fun factor of a 2 stroke alone is worth a 5hp deficit. Exhaust sound or lack of is worth a 5hp deficit. The easy starting is worth a 5hp deficit. If the tpi can someday be reliable and make the power of my carbs it's a win.

 

[Answ3r]

I’ve been playing around with a friends TE 300i
View attachment 360697View attachment 360698View attachment 360699

Will you keep the jacket straight on the pipe like that ? Don't think it will melt ? Also do you have a plate to go between pipe and engine to keep snow from coming in the front ? Looking good otherwise !

 

[boondocker99]

I ride a xcw in dirt and the gap from first to second is rediculous. If you use it in snow plan to gear accordingly so first will probably be useless and slip clutch to keep 2nd from bogging out.
The fun factor of a 2 stroke alone is worth a 5hp deficit. Exhaust sound or lack of is worth a 5hp deficit. The easy starting is worth a 5hp deficit. If the tpi can someday be reliable and make the power of my carbs it's a win.

Never had any issues with bogging going from first to second on my 19 TE300i which should have the same tranny. I am running a CMX which has a very low rolling resistance.

 

[boondocker99]

Have you checked your power valve adjustment? Seems some people have addressed similar issues with proper adjustment. High comp head and ecu tune can optimize things too...

I ride a xcw in dirt and the gap from first to second is rediculous. If you use it in snow plan to gear accordingly so first will probably be useless and slip clutch to keep 2nd from bogging out.
The fun factor of a 2 stroke alone is worth a 5hp deficit. Exhaust sound or lack of is worth a 5hp deficit. The easy starting is worth a 5hp deficit. If the tpi can someday be reliable and make the power of my carbs it's a win.

 

[GlennRMK]

The XC has a taller 1st and 2nd. 1st is around 2.28 on the XC-W and 2.06 on the XC. 2nd is 1.56 on the XC and 1.63 on the XC-W

3-6 are the same unfortunately

I ran a 2016 MH LT on my 11 300 XC. I would never put it on the W. The XC already feels a little gappy. An SX would be better but would probably have a 30 MPH top speed. I wouldn't do a LT with the 300 again either. 120 or 129 max.

It seemed liked my 2011 would never run consistently but had pretty good power with a PC pipe, shaved head and SX CDI. I would like to try a 300 XC TPI with a 120 or 129 kit and see if the TPI can make it run more consistent.

 

[eric82930]

Never had any issues with bogging going from first to second on my 19 TE300i which should have the same tranny. I am running a CMX which has a very low rolling resistance.

That's good to hear. What counter shaft sprocket? Does cmx have optional track sprockets? Gearing low enough will bypass the 2nd gear gap at the expense of top speed on roads. Most probably don't care but last years crappy winter we had an 8 mile road ride to get to the good snow. To compensate road speed on my sx 5 speeders I run 15t counter sprockets so my first is like most peoples 2nd. And same thing on my xcw trail bike is a dual sport I run 75mph+on the highway with 15/45 sprockets it really amplifies the gaps.

 

[boondocker99]

The XC has a taller 1st and 2nd. 1st is around 2.28 on the XC-W and 2.06 on the XC. 2nd is 1.56 on the XC and 1.63 on the XC-W

3-6 are the same unfortunately

I ran a 2016 MH LT on my 11 300 XC. I would never put it on the W. The XC already feels a little gappy. An SX would be better but would probably have a 30 MPH top speed. I wouldn't do a LT with the 300 again either. 120 or 129 max.

It seemed liked my 2011 would never run consistently but had pretty good power with a PC pipe, shaved head and SX CDI. I would like to try a 300 XC TPI with a 120 or 129 kit and see if the TPI can make it run more consistent.

Parts fiche indicates that on the newer TPI models only the first gear is different as is reported a few posts back... My setup runs good with a CMX 129. TS kits have horrible rolling resistance and rob power.

 

[boondocker99]

That's good to hear. What counter shaft sprocket? Does cmx have optional track sprockets? Gearing low enough will bypass the 2nd gear gap at the expense of top speed on roads. Most probably don't care but last years crappy winter we had an 8 mile road ride to get to the good snow. To compensate road speed on my sx 5 speeders I run 15t counter sprockets so my first is like most peoples 2nd. And same thing on my xcw trail bike is a dual sport I run 75mph+on the highway with 15/45 sprockets it really amplifies the gaps.

Yes, CMX has optional sprockets. Don't recall the specific sprockets I'm running now. I think the lower gearing issue you suggest is not really an issue when you have a 6 speed tranny as I do on a TE300i which should be the same as a XCW.

 

[byeatts]

Parts fiche indicates that on the newer TPI models only the first gear is different as is reported a few posts back... My setup runs good with a CMX 129. TS kits have horrible rolling resistance and rob power.

good info , They changed 2,nd gear on the TPI

 

[GlennRMK]

good info , They changed 2,nd gear on the TPI

That is incorrect. The gears are the same 2011-2021.

The owners manuals and the parts fiche show a different gear for 2nd between XC and XC-W. 16/25 for XC and 16/26 for XC-W.

IMO the XC should have the SX gearbox with a 6th added. That would be a nice improvement.