i have jetted my bike and put a full Yosh exhaust on and it still boils. Should I use a diffrent coolant? Bike only has a little over 100 miles on it. Any ideas?

Thanks,
Dwayne

Edited by tidrow55, 28 August 2012 - 02:19 PM.

My guess is your jetting is still to lean.I have an FMF Powerbomb header and FMF Powercore 4 SA . My jetting is 170 main, 48 pilot, middle clip on needle, 2-1/2 turns out on fuel screw. I raced a hare scramble in June with 100 degree heat and the bike never boiled. Runs pretty darn good. I've done all the mods,AIS removed, air box snorkel removed, etc. I run regular coolant that I use in my vehicles. Hope this helps.

EVANS WATERLESS COOLANT! I have used this since Day 1 &  HAVEN'T HAD ANY BOILING OVER OR LOSS OF COOLANT. Of coarse I would recheck your jetting & if everything checks out, then I believe EVANS is your answer.......
PS-I have had the JD  JETTING KIT installed on my bike since Day 1 also. I have never had to mess with the jetting since. I have had the RED NEEDLE installed from the get go & leave that needle in all year long. Good Luck.

Edited by GreenHornet450, 29 August 2012 - 06:30 AM.

What is the outside air temperature? Are you riding slow 1st gear trails? [low air flow over radiators] Are you idling more than a minute?  How is your coolant level? I have a similar setup and any of these things can still contribute to overheating.  Do you have any popping on decel? That would be a good indicator of still running lean on the carb.  A replacement coolant will help but all of these things will make her run hot. It doesn't necessarily mean you're hurting the bike though.  Just don't do it as a common practice.

Your hot start is not stuck is it???

My Hot Start was stuck and even though I don't need it, I was paranoid that it was stuck slightly open so I just fixed it this last weekend. I have heard it will run very hot if that is stuck open.

My fix was to pull the carb and Hot start cable out together, lay it on its side and bend the plunger tabs out so the cable end would release. Soak with PB Blaster in the pluger hole and put a screwdriver in and twist and rotate the plunger back and forth till free. Then put the cable back in and bend the tabs back in against the cable end and pull the plunger out with the cable. Then I used a dremel buffer head to clean out the plunger cylinder, blue buffer head like an eraser and then white felt. I put in a new plunger, spring, o-ring, and cable, all well greased.

Sounds good but you don't need to bend anything to get it a part.  If you disconnect the cable from the lever on the handlebar and then pull the cable out of the carb you just pull the plunger away from the spring and rotate the cable 90 degrees throug the groove in the plunger and the cable comes free.   The hot start induces more air to lean out the mix when it is hot  so any unburned fuel in the engine is blown out and keeps it from flooding or fouling.  It will run very lean and overheat very quickly even if it adjusted too tight.  Give Pit-Mans jetting specs a shot.  I saved my money and did not buy the JD jet kit.  I run a NVCR KX 450 needle 168 main and 45 or 48 pilot 1.5-2 turns out on the mix screw.  Get the remote screw!  It makes test ride adjustment easy. If you are more than 3 turns out on the mix screw, your pilot is too lean,.

Jetting will make little difference on how hot a water cooled engine runs. What does make a huge difference is airflow over/through the radiators. If you are doing 10mph single track, expect to have over heating issues. Install a fan. Ride faster.

That can be true, I ride primarily tight single track with temp 70-85 degrees or more, no fan, unibiker radiator guards, standard coolant, CV4 1.6 cap, no overheating issues.

William1, on 07 September 2012 - 11:13 AM, said:

  Try running with your hot start on and see how long it takes to boil over, not long, it leans your mixture.  Jetting has a ton to do with how hot your engine runs.

crazyal426, on 07 September 2012 - 05:49 PM, said:

True.

crazyal426, on 07 September 2012 - 11:09 AM, said:

That would be a good trick with the plunger stuck deep inside the carb. You will have to explain in more detail .

Oh ya, sorry for the misread, I thought of a different kind of stuck, in that case good job!!!!!!

blue ice coolant really helped mine!