18 gp 300

[pigpen966]

Hey Gang, went for my first hard 80km ride Sunday down here in Costa Rica. I moved down here from the states last August and brought my GP with me (don't ask how much the import was ). Been tooling around on the dirt tracks for a couple of months by myself and finally hooked up with some local enduro guys. Gotta say the riding down here is absolutely incredible!!!
Anyway, my trusty steed got hot and lost most of the coolant. Granted it is pretty warm down here, but no worse than Ohio in the late summer. It was rubber side up a few times, and I might have lost some coolant that way, but man she was smokin!! This is my 3rd gassy 300 and my older ones were never prone to overheating.
As far as jetting goes
N3CJ 3rd clip, 40 pilot, 178 main and air screw is 2 turns. Most of my throttle is between 0-1/2 maybe. I'm a lugger not a spinner. Head is still stock, bike runs perfect.
Mix is Motul 710 at 50:1 with pump gas.
All the white and orange pumpkins down here are running fans(cause they're weak).
Tomorrow I'm gonna pull the pump cover and check for issues there.
Any other suggestions?
P.S. Bike does have Rekluse EXP in it.

[Jakobi]

Not sure PP!! But my old 2010 and 2013 models were beasts that never cooked it.. I managed to make my 2018 have a little spit on its first ride. An orange bike through the same section was whistling like a kettle, but I didn't really feel like I did it hard either..

Mine might have just vented the little bit above the fins, but I'll be keeping an eye on it for sure.

[hamilton]

That Rekluse can generate a lot of heat if not set up just right.

[Jakobi]

No recluse on mine.. I was giving the clutch a good ol slip though. Not enough to make it sound unhappy! I was in mud and leaf liffer in rainforest fighting gravity.. not much airflow. I'll keep an eye on it!

[pscook]

One thing to consider is the rad cap. I know that with the 1.2 bar cap my 300 would vent a fair bit of water after a long climb, but the 1.8 bar cap (as recommended here) helped prevent further steam generation. It might be worth it to look at the rad cap seal and possibly upgrade to a 1.8 bar cap, just to prove the point.

[Jakobi]

Thanks Phil. I had a look at the cap seal before the ride, and there was a little crystalisation/build up in the neck. I just rubbed it back but ideally I need to hit it with something abrasive to clean it properly.

[pigpen966]

Found the culprit today. OEM Rad cap is a 1.8, apparently on one of my rubber side up excursions I bent the filler neck on the rad. Bent it just enough the cap wasn't sealing. I'll see if I can get er straightened out enough for the cap to seal. Probably pull the head and make sure nothin got cooked too.

[pigpen966]

Ok, so apparently I melted the head gaskets. Internals are ok, still have good compression. Cylinder, piston and rings looks good. I did get coolant in the motor, so I'm gonna flush everything with WD-40. I have some gaskets in stock. Does the outer O ring need to be stretched to go in the grove? Going to check the head for warping next.

[Jakobi]

Yeah outer o ring usually needs some light stretching and a dab of grease to hold it in place.

[pigpen966]

Thanks brother, all back together and good for some more thrashing!!