Has anyone else had this happen to them - I was out on my 320 yesterday and after a bit of a blast along a track (for a couple of miles maybe) I noticed it started spitting coolant out of the overflow. After it had cooled down and was topped up, all seemed well until it did it again after another longish blast along a track.

Thinking that Sherco must've made the fan / radiator big enough to cope with the heat generated from road / track work ,I investigated further and found that at low revs (maybe under 4000 rpm) the fan runs fine, but above that it stops dead !!!!!!! Surely this isn't a design feature...........

Has anyone else come acrosss this "feature" and how did you sort it ?

Has anyone else had this happen to them - I was out on my 320 yesterday and after a bit of a blast along a track (for a couple of miles maybe) I noticed it started spitting coolant out of the overflow. After it had cooled down and was topped up, all seemed well until it did it again after another longish blast along a track.

Thinking that Sherco must've made the fan / radiator big enough to cope with the heat generated from road / track work ,I investigated further and found that at low revs (maybe under 4000 rpm) the fan runs fine, but above that it stops dead !!!!!!! Surely this isn't a design feature...........

Has anyone else come acrosss this "feature" and how did you sort it ?

This sounds more like a voltage regulator problem..do a search ,see what comes up.

Not sure of the exact answer to this, but I can tell you a couple of things. Firstly, when filling the radiator, you need to just cover the cores and allow a bit of room at the top for expansion.

Next, if you are doing that many revs, surely you are moving enough to get some natural airflow past it?

And lastly, I did notice that Caby's bike seemed to be spitting a few drops of coolant when hot. Hard not to notice because it dripped on the hot exhaust and made smoke, but no one seemed to be overly concerned about it!

Copemech - I suspect I won't be using my bike as hard as Caby uses his and that the coolant spitting from his bike was "well deserved"...... my bike has a much easier life.

Checking it over last night, I found that at tickover there was 6 - 7 Volts across the fan terminals, but as I revved the bike up this dropped to around the 1 Volt level and the fan stops, so I'm definitely thinking it's the voltage regulator.

Watch this space .............

Copemech - I suspect I won't be using my bike as hard as Caby uses his and that the coolant spitting from his bike was "well deserved"...... my bike has a much easier life.

Checking it over last night, I found that at tickover there was 6 - 7 Volts across the fan terminals, but as I revved the bike up this dropped to around the 1 Volt level and the fan stops, so I'm definitely thinking it's the voltage regulator.

Watch this space .............

Possibly, seems odd though, did you ck it to earth(motor) to be sure there is good ground , as the thermo switch just closes to allow voltage to the fan, and that is relative only to proper ( ground) so if measured across the fan may be erronious due to poor grund contact, just a thought. Do you have a headlamp? Does it work?

The new voltage regulator arrived (from Rathmells in less than 36 hours - excellent service!!!!) and it took 10 minutes to fit.... and the fan now works again as it should. I'm off to Fort William tomorrow (not as a rider.......more a hillwalking and beer holiday ) so I won't get a chance to try it out for a week or so but I'm confident it'll be OK

Good job then!

Well done that man,enjoy Fort William

hi , i have a problem with my sherco 290 2003 fan, i belive it is the black box (regulatar) made by leonelli part number 2701. i cannot seem to locate one, i cannot find a contact number for rathmels, the fan works fine off a car battery, but will not work if i bypass the thermostat. it all leads back to the black box also belive it is called a diode. can anyone help , please many thanks stu