I have a 2005 Yamaha WR 450f and my friend has a 2005 YZ 450f with a Timbersled Kit. We are both experiencing carb ice issues that either have affected runability or being able to achieve Wide open throttle. I suspect that the lack of a tunnel top at the front of the track contributes to the problem. Some have suggested running a hot water loop to the carb. Any "how to" elegant solutions out their? Any one else experiencing the same? Does EFI solve the issue?
Carb Icing Timbersled Kit
- Thread starter AkBob
- Start date
Efi bikes don't freeze up, but we can't seem to keep the motors warm enough to get them out of "rich" mode. Which isn't that bad except we end up getting gas in the oil. I have half of a radiator blocked for todays ride, well see how that goes.
I have had carb ice issue on my Honda CR500 Timbersled. I did install heat strips (12V from McMaster-Carr) to the carb bowl and carb inlet, I have the airbox full of foam (to displace any snow), blocked off lower air inlet to the airbox, installed 2" snovents on the sides and back of the airbox. It's alot better, but still have issues from time to time in deep snow. Now I'm working on putting a small radiator in the airbox to help warm the air and melt snow that still makes its way into the airbox.
If anyone else out there has any great ideas I'd love to hear them?
If anyone else out there has any great ideas I'd love to hear them?
here is my thought
After an awsome weekend of snowbiking. So you know what i have 1998 kx 500 with home built kit like the mtn. horse. I have installed snowpre filter on the air filter and all air intake areas on the air box, including the top of the air box made a lid and prefilter meshed it. I'm not getting any snow in the air box any more period.
I have installed a heated mikuni tm40 carb also. It works much better but still gives problems in the deep powder.
I also made a plastic top to the tunnel to keep the snow from being thrown up to the motor from the track.
all this helps but the problem still exists. This weekend i noticed that it i was side hilling or just leaning to the left the problem would occur faster than if leaning to the right. Here is what the difference is. the chain case acts like a shovel lifting the snow right up to the top of my track and onto the carb. it is a snowball right now.
there are 2 things that i plan to do still.
1. wrap my carb with plastic wrap and take expando foam insulation and make a insulated carb mold.
2. change the design of the track frame and run the chain next to the track.
it will not be covered anymore so will have nothing on the outside of the frame just like the right side.
I'm sure that will fix all the problems we are having.
What do you think?
After an awsome weekend of snowbiking. So you know what i have 1998 kx 500 with home built kit like the mtn. horse. I have installed snowpre filter on the air filter and all air intake areas on the air box, including the top of the air box made a lid and prefilter meshed it. I'm not getting any snow in the air box any more period.
I have installed a heated mikuni tm40 carb also. It works much better but still gives problems in the deep powder.
I also made a plastic top to the tunnel to keep the snow from being thrown up to the motor from the track.
all this helps but the problem still exists. This weekend i noticed that it i was side hilling or just leaning to the left the problem would occur faster than if leaning to the right. Here is what the difference is. the chain case acts like a shovel lifting the snow right up to the top of my track and onto the carb. it is a snowball right now.
there are 2 things that i plan to do still.
1. wrap my carb with plastic wrap and take expando foam insulation and make a insulated carb mold.
2. change the design of the track frame and run the chain next to the track.
it will not be covered anymore so will have nothing on the outside of the frame just like the right side.
I'm sure that will fix all the problems we are having.
What do you think?
On are 2moto kits we remove the air box and use a filter with a nylon pre filter that can be slapped to remove snow. Also we raise the carb vents and crank vent so they dont ice over. Check out bills site www.2moto.biz
i forgot
I also did the carb vents to the air box. tried the pod filter also. In my case it is not so much of a snow in the filter as it is snow on the carb body. i did a rejet once and when i removed the carb i found a film of ice over the vent holes in the throat of the carb, that is what made me install the heated carb.
The explorer kits we run don't seem to have any problems. carb is always clean no ice on it at all.
I also did the carb vents to the air box. tried the pod filter also. In my case it is not so much of a snow in the filter as it is snow on the carb body. i did a rejet once and when i removed the carb i found a film of ice over the vent holes in the throat of the carb, that is what made me install the heated carb.
The explorer kits we run don't seem to have any problems. carb is always clean no ice on it at all.
pic
did the frame widening mod this weekend. have to finish the tunnel top again but should be ready for the pow now.
did the frame widening mod this weekend. have to finish the tunnel top again but should be ready for the pow now.
Im running a ktm 505 and I am also having issues with snow in the airbox I tried stuffing it with foam but that didn't help so I came up with the idea of building a snorkel kind of like the turbo yamaha guys run. I got some two inch is hose and ran it through my air box and above my rear fender and put a filter on the end of it. In theory I thought it would work great because there is nearly no snow flying around up there. Apparently these thumpers need alot of air because it would just die after half throttle, I'm no mechanic but I think that if the hose was shorter it might work I might find a larger hose and try again. Right now I just removed the back plastic part of the air box and the side panels leaving the air box wide open this way it can't fill with snow so far it is working great but it is a lot warmer recently so the snow isn't as powdery as it was two weeks ago. I'm not sure if I'm on the right track what do you guys think should i keep pursueing the snorkel idea.
snorkle
it will work but you will have to run a large tube. the longer the tube the more restriction you have. are you actually haveing snow building up in the air box?.. I put the slp prefilter over the vent holes and made a lid for the top and covered that too. I'm not getting the snow in the air box but the icing is still the same, caused by the snow against the carb, casued by the chain case acting like a snow shovel. JM2$
it will work but you will have to run a large tube. the longer the tube the more restriction you have. are you actually haveing snow building up in the air box?.. I put the slp prefilter over the vent holes and made a lid for the top and covered that too. I'm not getting the snow in the air box but the icing is still the same, caused by the snow against the carb, casued by the chain case acting like a snow shovel. JM2$
Yes in powder my air box will completely fill up with snow I even lined the gaps under the seat with foam and siliconed between body panels trying to stop it from filling up nothing worked. As far as my carb icing up I have found that if I run a splash of gas line antifreeze I never have a problem even in minus twenty five weather with my carb completely iced over so I can't even see the choke. So it seems we are having completely different issues both resulting in not good times.
I am running a TS Mt. Horse kit on my KTM 525 and I was having some major problems with snow in the air box as well and I think I have resolved this issue. I just duct taped all of the seams, added foam under the seat and drilled six 1.5" holes in the cover and put frog skins over them and it ran really well this past weekend. I don't think I have experienced any carb icing. What are you guys describing as carb icing?
ice inside the throat
Originally i was having problems with snow in the air box. I then installed the slp filter skin over all the air inlets on the airbox. made a lid on the airbox also and covered that also.
I thought that would solve everything, but soon found out other wise. The problem i have now is that inside the airfilter side of the carb a thin film of ice forms and covers the vent holes in the carb. I saw this when i pulled the carb to change main jet.
since then i did all the previous mods that mentioned earlier about changing the frame and drive.
Originally i was having problems with snow in the air box. I then installed the slp filter skin over all the air inlets on the airbox. made a lid on the airbox also and covered that also.
I thought that would solve everything, but soon found out other wise. The problem i have now is that inside the airfilter side of the carb a thin film of ice forms and covers the vent holes in the carb. I saw this when i pulled the carb to change main jet.
since then i did all the previous mods that mentioned earlier about changing the frame and drive.
Ran my Honda CR500 Mountain Horse Saturday. No carb ice problems, but snow was pretty set up. A real powder day will be the test.
Airbox filled with foam, top of airbox with large scotch-brite pad.
Airbox sides sealed except for three 1.5 holes with frogskinz.
Carb has two 12V heat pads (one under bowl, one t
op of inlet).
Carb insulated on the outside with foam and carb shield to block snow/ice buildup
Fuel anti-ice additive.
KTM makes a carb heat kit p/n KTM Part Number(s): 55131003044
I'll see later this week if I can install the KTM heater kit on my Keihn carb.
It's just a heat probe that screws into the carb. Probably more efficient than my heat pads.
Airbox filled with foam, top of airbox with large scotch-brite pad.
Airbox sides sealed except for three 1.5 holes with frogskinz.
Carb has two 12V heat pads (one under bowl, one t
op of inlet).Carb insulated on the outside with foam and carb shield to block snow/ice buildup
Fuel anti-ice additive.
KTM makes a carb heat kit p/n KTM Part Number(s): 55131003044
I'll see later this week if I can install the KTM heater kit on my Keihn carb.
It's just a heat probe that screws into the carb. Probably more efficient than my heat pads.
any new info
just wondering if anything has changed lately. I put my stock kehin carb back on the kx cause i could not get the right jetting for the mikuni i used.
I had a small tube welded to the bowl just below the gasket surface to run my coolant through to help from icing over the vent holes. Then i make a small plastic box that fits tightly around carb, and filled with foam to inslulate the carb. installed a 2inch tube up under the fender and installed a pod filter to that and drilled in another 6 1inch holes and covered them with screen also. Will see how it works in cooke city this weekend.
just wondering if anything has changed lately. I put my stock kehin carb back on the kx cause i could not get the right jetting for the mikuni i used.
I had a small tube welded to the bowl just below the gasket surface to run my coolant through to help from icing over the vent holes. Then i make a small plastic box that fits tightly around carb, and filled with foam to inslulate the carb. installed a 2inch tube up under the fender and installed a pod filter to that and drilled in another 6 1inch holes and covered them with screen also. Will see how it works in cooke city this weekend.
Hi J&L,
I've been carb -ice free on my CR500 for 3 weekends now in 18 - 24" new snow and 35 to -10 degrees temperatures.
I have foam around the carb (not as nice a job as yours, but same idea as to keep ice/snow from directly sticking to the car) and sno-vents for my stock airbox with some foam inside. For heat I installed a KTM carb heat kit which is basically a heat probe that screws into the carb body. For my Keihn I had to drill and tap a spot for the probe to screw into.
I just leave the heat on and ride all day with no issues. Last weekend ran 65 miles with sled buddies on only 4.5 gallons. Never possible before because once carb iced over I ran so rich I couldn't hardly carry enough gas for a full days ride let alone run fast enough to keep up with the sleds.
At the end of the day I pull the seat and pull out the soaking wet foam in the airbox and let it dry. The foam around the carb dries on its own.
Let me know if you have any questions. Good luck.
I've been carb -ice free on my CR500 for 3 weekends now in 18 - 24" new snow and 35 to -10 degrees temperatures.
I have foam around the carb (not as nice a job as yours, but same idea as to keep ice/snow from directly sticking to the car) and sno-vents for my stock airbox with some foam inside. For heat I installed a KTM carb heat kit which is basically a heat probe that screws into the carb body. For my Keihn I had to drill and tap a spot for the probe to screw into.
I just leave the heat on and ride all day with no issues. Last weekend ran 65 miles with sled buddies on only 4.5 gallons. Never possible before because once carb iced over I ran so rich I couldn't hardly carry enough gas for a full days ride let alone run fast enough to keep up with the sleds.
At the end of the day I pull the seat and pull out the soaking wet foam in the airbox and let it dry. The foam around the carb dries on its own.
Let me know if you have any questions. Good luck.
Thanks
That is good to hear. I don't have power on the kx so I have to resort to coolant heat. Your bike looks great. What did you do for jetting? I have mine the same as summer 1500 ft setup to ride at8k ft in the cold. Just a starting point.
That is good to hear. I don't have power on the kx so I have to resort to coolant heat. Your bike looks great. What did you do for jetting? I have mine the same as summer 1500 ft setup to ride at8k ft in the cold. Just a starting point.
I ride 9000 - 11000 feet ASL. Jetting-wise I started with same settings as my summer rides (52SJ, 3rd clip/groove from bottom and 162MJ) but went up on the main to a 165MJ because I was worried about leaning out at sustained high RPM and pulls. Anyway, after some trial and error, the best jetting for me is actually 1 clip leaner on the needle (4th clip/groove from bottom) and one jet richer on the main (165MJ).
Gives me real clean midrange. It's a little fat on the top, but much better than the next leaner 162MJ.
Next step is I'm going to install a Intellajet from Thunder Products so I can adjust the MJ on the fly.
I have a digital A/F gage on the bars which helps alot during the tuning process. (I run a 20HP BossNoss NO2 system too).
Gotta love these bigbore 2-Strokes..... I haven't even changed a plug yet this season. (Hope I just didn't jinx myself by saying that).
Gives me real clean midrange. It's a little fat on the top, but much better than the next leaner 162MJ.
Next step is I'm going to install a Intellajet from Thunder Products so I can adjust the MJ on the fly.
I have a digital A/F gage on the bars which helps alot during the tuning process. (I run a 20HP BossNoss NO2 system too).
Gotta love these bigbore 2-Strokes..... I haven't even changed a plug yet this season. (Hope I just didn't jinx myself by saying that).
Thinking I want to run a coolant line back to my carb to prevent icing but not sure what type of tubing to use or where to tee into the coolant system. The bike is a CR500, anybody have some advise? I really don't want to weld anything to the carb so I would be looking at just coiling some tubing around the carburetor.
weld it
u could get an extra float bowl and weld the 5/16 od tube to it for winter use. it will b hard to get the heat to transfer good by just wrapping it around the bowl i think. It helps alot to make a nice box to mount around the carb like i had done too. if you want i could get you some better pics of what i had.
u could get an extra float bowl and weld the 5/16 od tube to it for winter use. it will b hard to get the heat to transfer good by just wrapping it around the bowl i think. It helps alot to make a nice box to mount around the carb like i had done too. if you want i could get you some better pics of what i had.
