No more RICH EFI in the cold! (t-stat install)

[brentn]

I'll try looking around locally and see what I can find.

Do you have a part number from the manufacturer of the t-stat?

Not ready to purchase just yet, christmas really blew a hole in my budget so it'll have to wait until a few weeks at the least.

[tech24]

I'll try looking around locally and see what I can find.

Do you have a part number from the manufacturer of the t-stat?

Not ready to purchase just yet, christmas really blew a hole in my budget so it'll have to wait until a few weeks at the least.

I don't know the part number and there isn't one on the element itself. I do know wilkkarts makes the housing and the t-stat is a stant.

I emailed guhl motors to see if there housing is the same and if they could get a hotter temp. I'll see what they say. Worst case is use their housing with the other element if I can get the stant p/n.

[brentn]

I appreciate your help. No rush at all, I'll pop this thread back up when I am ready to actually order and then I'll be doing alot of looking myself.

You say the T-stats are made for kart racers... well we have a couple of go kart tracks in which races are held in the summer all the time. I'm sure if I go down there with a couple of pics I could probably get them to order me something.

Once again, thanks tech24!!

[brentn]

Sorry for flogging this thread with posts, but it's good info to clarify things for people looking to do the same setup.

You mentioned that you used the jegs check valve and it was the only way to get the t-stat to work properly. what kind of fittings did you use with the jegs one way? Or did you just slip the little bit of rubber hose on each end onto the threads? Or did you remove the nipples on the one way and install your own nipples that weren't threaded?

[tech24]

Sorry for flogging this thread with posts, but it's good info to clarify things for people looking to do the same setup.

You mentioned that you used the jegs check valve and it was the only way to get the t-stat to work properly. what kind of fittings did you use with the jegs one way? Or did you just slip the little bit of rubber hose on each end onto the threads? Or did you remove the nipples on the one way and install your own nipples that weren't threaded?

no problem, I would have liked to put hose fittings on the check valve but couldn't find anything and its almost too large to fit in the hose. It was a pain in the butt. I coated the treads with liquid thread sealer and pushed hoses on it. I heated the hose up with a lighter several times in order to get them on. At the left radiator end I took the OEM hose that goes from head to top of RH radiator and cut a small piece out of the bend part and used that to connect the valve to the radiator outlet.

The thermostat worked without the valve but not well. There was enough backwards flow to drop temps to 140 or lower. It would work without it if you could run the bypass hose inline with the RH outlet but there isn't enough room in the short hose between the outlet and water pump. Without the check valve when I had clear hoses on for testing I noticed in the outlet hose of the RH radiator that when you crack the throttle the w/p was pulling more than it was pushing and I could see a small stream and lots of air which could cause air pockets or cavitation in the w/p. This went away when when the LH outlet was pinched off and when check valve was installed.

If I get time today I'll try downloading a KTM manual and see if there is coolant flow diagrams. I tried before but it locked up my PC so I'll try again and see how theirs works.

Edited January 27, 2011 by tech24

[tech24]

ok KTM manual is strange and useless....no diagram that I could find. You may also try joining a shifter kart forum and asking for other brands or options available or even see if there are any used ones for sale. I wish I had the money and time I'd put some complete kits with everything needed together. Hopefully I hear back from guhl motors todays.....stay tuned.

[tech24]

I appreciate your help. No rush at all, I'll pop this thread back up when I am ready to actually order and then I'll be doing alot of looking myself.

You say the T-stats are made for kart racers... well we have a couple of go kart tracks in which races are held in the summer all the time. I'm sure if I go down there with a couple of pics I could probably get them to order me something.

Once again, thanks tech24!!

Yeah check with the kart guys, hopfully some of them run 4 strokes. 2 stroke stuff seems abundant but not 4. Also Erik at epic racing, assuming he renews his sales license and plans on doing business will probably restock come summer time.

[Gunner354]

http://www.cometkartsales.com/store/engine/images/bypasthrm.jpg

http://www.cometkartsales.com/store/axles/water.htm

Take a look at this one. Sounds like Yamaha needs to incorporate a t-stat into the head.

[tech24]

http://www.cometkartsales.com/store/engine/images/bypasthrm.jpg

http://www.cometkartsales.com/store/axles/water.htm

Take a look at this one. Sounds like Yamaha needs to incorporate a t-stat into the head.

Yeah that would be ideal. The comet unit would work too bad its not a hotter temp.

[moto278]

out of curiosity, i know the thread is old. but did you ever have any issues with a 'bog' or hesitation in throttle before the tstat in cold weather? such as under 30 degrees F? i have been and it seems to be happenening when the temps are colder. the first warm day this year (week ago) was 50s it didnt do it at all. but the following day and yesturday it was mid 30s and was bogging after riding for a while. thought it was low fuel but topped it off nd continued to do it

[brentn]

out of curiosity, i know the thread is old. but did you ever have any issues with a 'bog' or hesitation in throttle before the tstat in cold weather? such as under 30 degrees F? i have been and it seems to be happenening when the temps are colder. the first warm day this year (week ago) was 50s it didnt do it at all. but the following day and yesturday it was mid 30s and was bogging after riding for a while. thought it was low fuel but topped it off nd continued to do it

I never did, and I was running my bike in much colder temps than that.

[brentn]

http://www.cometkartsales.com/store/engine/images/bypasthrm.jpg

http://www.cometkartsales.com/store/axles/water.htm

Take a look at this one. Sounds like Yamaha needs to incorporate a t-stat into the head.

First link looks like a winner there. I wonder if the R6/R1 sport bike T-stat's would fit in that housing? They are 4 strokes, I would think their optimum temp would be the same as our bikes?

Summer or winter, this mod is a must IMO.

[tech24]

out of curiosity, i know the thread is old. but did you ever have any issues with a 'bog' or hesitation in throttle before the tstat in cold weather? such as under 30 degrees F? i have been and it seems to be happenening when the temps are colder. the first warm day this year (week ago) was 50s it didnt do it at all. but the following day and yesturday it was mid 30s and was bogging after riding for a while. thought it was low fuel but topped it off nd continued to do it

I haven't had that problem, Brentn already replyed and as he said he's rode his in really cold temps.

[brentn]

-15 celcius one day, HRC has also ridden in temps this cold. The only issue I had was when I had the bike in the truck driving out, it supercooled the engine in which it would not start below -15. In the garage, up to -25 it would start no problem, but put it on a truck with the windchill hitting the bike for a 40 minute drive and your SOL.

[Noppy]

What would your computer think if you would simply interrupt the wiring from the temperature signal with a switch?

Would it assume a standard value, which is more favourable to us? A switch with a light, which would remind us that we are running in 'limp mode'?

[grayracer513]

It might substitute a fixed value for the CT parameter and carry on, or it might go to a base default mode, running fixed timing and a base fuel curve, which would not be very functional.

[Noppy]

I wouldn't mind driving this way for half an hour and then switching to full mode. I have a Trailtech Vector mounted, on which I could see the actual water temperaturen. As soon as it would be in operating temperature, I would switch on the sensor:ride:

It would be a very cheap solution. All other options would make it prone to water leaks or loosing all water at once. And add more weight.

[lanham]

I found this. http://www.gassavers.org/showthread.php?t=5344

[lanham]

Another one: http://members.cox.net/watt-man/TB%20order1.htm

[brentn]

What would your computer think if you would simply interrupt the wiring from the temperature signal with a switch?

Would it assume a standard value, which is more favourable to us? A switch with a light, which would remind us that we are running in 'limp mode'?

Like a car, I would think that it would go into "limp" mode, in which it would run very poorly.