07' Boiled over!!!

desertgasser300 · #1 05-22-2012, 03:05 PM

Managed to boil over my 07' 300 yesterday,

Altitude of 2500 ft.
Temps. 100F

40 pilot
second clip from bottom on a CEK needle
175 main

1.4 bar (new) rad cap

This is a first for me and was extremely surprised by this. It was a long, loose and rocky hill climb. Mostly second gear for the climb in the pipe. Crested the hill and noticed it boiling. Let it cool down, lost maybe 8 oz. of fluid. Once it cooled off it never boiled again finished the last 50 miles of the ride.

andoman · #2 05-22-2012, 03:22 PM

Were you slipping the clutch a lot? On my Orange bikes that was THE quickest way to get them hot.
If you find that it is boiling over more than it used to, it may be the new rad cap. You wouldn't be the first to be let down by a brand new unit.

Jakobi · #3 05-22-2012, 03:38 PM

Plus one.

If this has only just started in conjunction with the new rad cap then thats where I'd be looking first.

Anything else changed?

stainlesscycle · #4 05-22-2012, 04:52 PM

i'm running 172 main at similar altitude (2000ft). n1eg needle. maybe 170 at 90+ degrees

desertgasser300 · #5 05-22-2012, 05:45 PM

Der....I meant a 175 main.

It has never boiled before or even on the return trip later that day.
Wasn't slipping the clutch, it has a rekluse in it.

I did forget to mention that as I let it cool I dropped the needle to the middle clip. It would burble a bit in the mid, but as long as it didn't boil I was o.k. with that. The rad cap is new, but like 2 months of use new.

My concern for all of this is the enduro I have coming up this Sunday. 50 miles in 3000 to 6000 elevation with temps in the highs 80's to mid 90's

stainlesscycle · #6 05-22-2012, 05:54 PM

still gots the old radiator cap? i would put that back on.... you've regularly ridden at this temp and elevation right?

Jakobi · #7 05-22-2012, 05:58 PM

Double check the cap if you can. Have a look in the rad with the engine running and make sure there is good water movement. Maybe check the water pump impeller just to be safe.

Do you run a catch tank? Any chance the rad was over filled and just spat its load? Or was it really really boiling. Any other signs of lean running? Hanging idle? Any air leaks? Carb boots, LHS main seal?

GMP · #8 05-22-2012, 07:18 PM

It may be a combination of the conditions and being borderline lean in the midrange with that needle. That needle is smooth because its little tight with fuel. For your race at higher altitude it may be fine.

desertgasser300 · #9 05-22-2012, 08:22 PM

GMP, you maybe right. I have mostly riden at around 1100ft with the needle where it is but the single track I ride there I never really get on it like I did the other day on that hill. I didn't realize that particular needle was so lean. Maybe the reason why I see very little smoke and virtually no spooge with that needle setting. I think I would rather be a bit rich then to lean. Spark plugs are cheaper then a top end!

I have the upgraded billet impellor and it is moving water through the rads.

Jakobi · #10 05-22-2012, 08:39 PM

I just plotted it out graphically. CEK#2 is very lean particularly so at 1/4 to 1/2 throttle. For example most people here are running 38 N3CH#2 172/175 for altitude. Comparing to 40 CEK#2 175 they are very similar from 1/2 throttle to WOT. The CEK is around 11% leaner at 1/4 throttle though.