KTM 300 XC-W 2008, Misha Subo, please help me, I will be installing . . .

Ben 500RR-S · Oct 27, 2018

. . . the third Camso DTS 129 kit on the 2008 KTM 300 XC-W. My BIL's bike.

I will be buying a Ski Doo Expedition from him so my wife can ride it and we can all go riding and my brother in law will get a Camso DTS 129 kit for the bike and I will install it on the KTM.

Is there anything I need to know or that I need to get for the 300 XC-W to make it all run good?

Engine jacket.

Thermobob?

Heated carburetor?

My appreciation in advance.

Misha Subo · Oct 28, 2018

I have not installed any of those often talked about items on either of our 2 xcws. No carb heat, no filter jacket or skins...nothing so far. Yes, these things were all on my list of things to do last winter but just got too busy. I started to plumb up my own glycol heated handle bar system and air-charged forks but did not finish when spring came around and both of those mods would not make an engine difference anyway. They are on my 2019 list once the garage is insulated and heated this fall. Also, put a thermometer style radiator cap on both bikes to monitor rad temps which was helpful in comparing both bikes which are identical in all ways except using the Suzuki needle/jet in one of them.

Did I have running problems last season up here in sub/sub zero great white north? ...no, not really. Just the first ride during x-mas in -20 deg temps was a little troublesome getting the bikes started and one of the xcws has a much higher operating temperature once warmed up which could be due to a small leak in the rad-half. I think this year we will play by ear and do the minimum trickery only if needed but definitely finish off the handle bar heat and charged forks. A stiffer front suspension will help with control but really very happy with the 2T bikes on the snow and Camso's kit so far (4-5 rides last winter).

CATSLEDMAN1 · Oct 28, 2018

300 ktm

in the backwoods of Montana you won''t ride many days without carb heat. Hit the wrong conditions and a half mile at a time limping back to the truck maybe.
along with that cover the motor to help, for sure a 2 stroke thermo bob, some get by with stock KTM ( which years ?). I like a wrapped pipe becuase in lots of fluff otherwise clouds of steam slow going up in your face fogging the best goggles.

after that the list is endless. firmer forks......good
better foot pegs or cover stock with bike inner tube
temp gauge
I have no first hand experience with the Comso ski to make it handle ?

M5- · Oct 28, 2018

My main complaint with the Camso ski is the" no mans land feeling" going from the center runner to an outside runner when cornering hard on the trail. Basically you have to lean the bike over and hope and pray the outer ski skeg hooks up. They did exactly what I thought it needed for 2019. There is a new deeper outer keel with a vertical component like the Yeti ski. They have also added 4 ribs to the corners of the ski in order to add more torsional rigidity. Both of these changes I think are directed towards improved trail manners. In the deep I found the ski is pretty decent because of the large shovel and its huge width.

As for your 300, I wouldn't run without carb heat, I've had a 2T with no carb heat freeze wide open and its no fun. Sorry MS but 4-5 days is not a test. The thermobob, maybe take it or leave it, I don't have one I just block off rads as needed. I would spend the money for a real temp gauge though and mount the sensor at the head. Those rad cap things are crap they are inaccurate for true head temps and they are slow. Watch a digital temp gauge and you will see how fast your temps change.

M5

Sheetmetalfab · Oct 28, 2018

M5- said:
As for your 300, I wouldn't run without carb heat, I've had a 2T with no carb heat freeze wide open and its no fun. Sorry MS but 4-5 days is not a test. The thermobob, maybe take it or leave it, I don't have one I just block off rads as needed. I would spend the money for a real temp gauge though and mount the sensor at the head. Those rad cap things are crap they are inaccurate for true head temps and they are slow. Watch a digital temp gauge and you will see how fast your temps change.

M5

Yep.

Misha Subo · Oct 28, 2018

I did a little ice racing 30+ years ago and had carb icing issues, in what seemed to be far warmer temperatures than last winter's snow bike outings. I think icing tends to be influenced by humidity as well. Up here in Southern Ontario it is dry by the lake in the winter but more humid than most regions during the summer...but I do plan to address the carb heating issue this fall just for fun and before I have to snow shoe home.

I bought a new lathe so I will attempt an intake heater circuit similar to the one I was posting here last winter. I want to keep the stock lower hoses and t-stat for summer use and remake a new carb/handlebar heat circuit just for winter - anyone have any ideas on this? I have already bought the fittings and lines for carb and handle bar heat but got side tracked by ski trips last winter. The plan is to do a combo ski/snow bike trip out in Quebec this February so I want to be reliable enough. Before you know it the winters over!

Sheetmetalfab · Oct 28, 2018

Misha Subo said:
I did a little ice racing 30+ years ago and had carb icing issues, in what seemed to be far warmer temperatures than last winter's snow bike outings. I think icing tends to be influenced by humidity as well. Up here in Southern Ontario it is dry by the lake in the winter but more humid than most regions during the summer...but I do plan to address the carb heating issue this fall just for fun and before I have to snow shoe home.

I bought a new lathe so I will attempt an intake heater circuit similar to the one I was posting here last winter. I want to keep the stock lower hoses and t-stat for summer use and remake a new carb/handlebar heat circuit just for winter - anyone have any ideas on this? I have already bought the fittings and lines for carb and handle bar heat but got side tracked by ski trips last winter. The plan is to do a combo ski/snow bike trip out in Quebec this February so I want to be reliable enough. Before you know it the winters over!

Humidity comes from snow melting off the pipe and engine. (Steam)

Also a 2 stroke carb venturi is especially susceptible to causing moisture to freeze and stick the slide.

I’m guessing you never rode in deep enough snow to have icing issues.

My 2 stroke had icing issues at 34 degrees. (From the cooling effect of fuel air venturi)

Robbie · Oct 28, 2018

Carb ice is a temperature/ dew point issue.

https://www.atsb.gov.au/media/47763/carb_icing.pdf

M5- · Oct 28, 2018

Aircraft carb heat comes on at like 6 or 7 degrees C cant remember which is in the 40's F. Humidity is the enemy. The air going through the carb at high velocity creates wind, condenses and then freezes the moisture in the air, more moisture more ice. That's why you can still get your carb un-frozen even when its a little below freezing out when the bike is just idling. No air movement no wind chill.

M5

Misha Subo · Oct 28, 2018

Anyone have a part number or Canadian source for a T-fitting that would through flow and hose clamp the standard rubber 3/4' dia. rad hose with a 1/8-27NPT female thread cross hole for feeding to/from the carb heater circuit?

tek9tim · Oct 28, 2018

M5- said:
Aircraft carb heat comes on at like 6 or 7 degrees C cant remember which is in the 40's F. Humidity is the enemy. The air going through the carb at high velocity creates wind, condenses and then freezes the moisture in the air, more moisture more ice. That's why you can still get your carb un-frozen even when its a little below freezing out when the bike is just idling. No air movement no wind chill.

M5

Uhhhh.... On solid objects, wind will only hasten the object reaching equilibrium with the ambient air, it won't make them colder than the ambient air. What's happening in the carb has to do with pressure changes, not just air velocity.

As air is forced through a constriction (venturi), the pressure is increased. When the air comes out the other side of the constriction, the pressure is reduced. When you reduce the pressure of a gas (talking about the state of matter, not fuel, though it's true for that too), the temperature drops. If there is moisture in the air, and the dew point is above the reduced temperature behind the venturi (and that reduced temp is below freezing), the moisture will condense out and freeze. Hence, why icing occurs in a carb. The more dramatic the venturi, the more intense the icing potential. Those HV Lectrons would probably be pretty bad.

If you're unsure about the temperature of a gas dropping as the pressure drops, grab hold of one of those little CO2 cartridges used to air up bike tires while you're puking it out. Or look at a BBQ propane tank, or a computer duster.

tek9tim · Oct 28, 2018

Misha Subo said:
Anyone have a part number or Canadian source for a T-fitting that would through flow and hose clamp the standard rubber 3/4' dia. rad hose with a 1/8-27NPT female thread cross hole for feeding to/from the carb heater circuit?

Raze uses those for their heated handlebar kits. Thermobob uses one with 1/4" NPT. I bet either company would drop one in the mail.

Misha Subo · Oct 28, 2018

It's a cinch to make them up on my lathe with a bit of square aluminium bar stock but the lathe won't be re-installed in the shop for another month. I'm having a hard time finding a commercial t-fitting in 1/8NPT. I prefer 1/8 to 1/4 as the fittings are less bulky and I have them already.

M5- · Oct 28, 2018

tek9tim said:
Uhhhh.... On solid objects, wind will only hasten the object reaching equilibrium with the ambient air, it won't make them colder than the ambient air. What's happening in the carb has to do with pressure changes, not just air velocity.

As air is forced through a constriction (venturi), the pressure is increased. When the air comes out the other side of the constriction, the pressure is reduced. When you reduce the pressure of a gas (talking about the state of matter, not fuel, though it's true for that too), the temperature drops. If there is moisture in the air, and the dew point is above the reduced temperature behind the venturi (and that reduced temp is below freezing), the moisture will condense out and freeze. Hence, why icing occurs in a carb. The more dramatic the venturi, the more intense the icing potential. Those HV Lectrons would probably be pretty bad.

If you're unsure about the temperature of a gas dropping as the pressure drops, grab hold of one of those little CO2 cartridges used to air up bike tires while you're puking it out. Or look at a BBQ propane tank, or a computer duster.

There ya go I stand corrected

M5

Misha Subo · Oct 28, 2018

I remember, back in the day before my time, the old vw bugs had an accessory air conditioner mounted on the passenger side window that cooled incoming rammed air from evaporation of the breeze running through a tray of water first.

tek9tim · Oct 29, 2018

Misha Subo said:
It's a cinch to make them up on my lathe with a bit of square aluminium bar stock but the lathe won't be re-installed in the shop for another month. I'm having a hard time finding a commercial t-fitting in 1/8NPT. I prefer 1/8 to 1/4 as the fittings are less bulky and I have them already.

Yeah, affirm on 1/8 being a better option. Raze uses exactly what you're looking for. I'm willing to bet they'll ship you one. I have one that I likely won't need, but I won't be sure until next weekend once I get the rest of the brass I need to hook up my system. I'd drop it in the mail for you if you haven't solved your problem by then, as long as you pay the shipping.

Ben 500RR-S · Oct 29, 2018

In a way, it is good to know that you didn't add any of that "trickery" to your 300 XC-W's.

Probably like you, we don't have the bottomless powder and the conditions that they guys out west have as we are in central VT, in about 1,000' of altitude with just rolling hills and no mountains. My BIL ran the stock, dirty air filter last winter with no trouble.

I think that once I put the Camso kit on his bike, we'll run it and see how it goes with no carb heat or engine jacket or even wrapping of the pipe. We have a bunch of snowmobiles and even a Bombardier Snow Cat if it is ever needed for a serious extraction.

Answ3r · Oct 30, 2018

I ride in QC, Canada so probably similar condition to you on a '09 300XC.

Foam air filter is a bad idea, buy the outerwears filtercover and modify a stock filter cage to hold it properly.

I did a big skid over the pipe on mine and shrouded the engine to keep the heat in and snow out of the head and carburetor.

I use the KTM electric carb heater and have a vented cover with outerwear in the hole (slows down the airbox snow fill up)

On special days, I still need to empty my airbox once in a while.

Still had my carb freeze on me ONCE last year, after a long, 4th and 5th gear run down a powdery trail.

Ben 500RR-S · Nov 13, 2018

I had ordered two DTS 129 kits last year from the dealer I bought my Beta from but for some reason, they charged me freight last year for both kits and wanted to again this year for the kit for my BIL's KTM.

I'm glad I called their sister store that is a LOT closer to me, like 9 miles away vs 26 miles away as they are getting me the kit for $4,999 and not charging me the freight which if I remember was over $200.

Now I wait for them to call and tell me that it is there so I can get it on my BIL's bike. I bought his 2011 Expedition 600 ACE.

M5- · Nov 13, 2018

So you are paying $4999 USD? Camso kits are $4999 Cdn here which is 3500 USD. Might be worth a road trip.

M5

KTM 300 XC-W 2008, Misha Subo, please help me, I will be installing . . .

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