just been on a 40 mile round trip, running temp was past its normal temp posistion.
when i stopped i immediately checked the viscose fan , and it turned exactly the same as when its cold.
is that right.
i have recently changed the head because of over heating ,bought a new radiator and loads of bits of pipe. took the thermostat out and drove it for a few days , and the water rushed through the system , so the pumps ok. thermostat opens properly to.

Once the engine reaches

Once the engine reaches above operating temp, the fan should lock in. I don't know what temp this is, but since you are running hot and it hasn't locked in, I assume that the viscose part of the fan has malfunctioned. These are expensive to buy, but I have seen some second hand ones on Ebay now and again.

Hope this helps.

hi, can i drill a nut and

can i drill a nut and bolt through it and lock it that way.

it didnt look that deep !!!!


Assume you refering to a Fourtrak.

You can just dismantle and rebuild, inserting a cardboard section in the vane/oil area to lock up the fan,( posts are on site re this method) or go down the drill and bolt method ( think about the balance of fan unit , as to wear on the water pump bearings). But I would suggest trying the replacing the fluid method. Lots of post on site ( use the search box to the left of this page) re this problem.

And yes I have a over heating problem and have to drive with this in mind, though just in motorway driving, aggressive at 60/70mph plus, though the girl was not built as a motorway cruiser or for this style of driving. So I keep an eye on all posts re overheating re Fourtraks.

Edward (ews) '92 Fourtrak 2.8 TDX

viscose fan


there is a thread on here about stripping and rebuilding the viscose fan i have done it and i think it tooh 20 mins to do you will just need some silicone oil from a model shop as its used in rc cars for the shocks and diffs...i will search and try to find the thread just dont drill it its not nessesary


Fan problems

I was about to suggest this link, but found ' RRW900' had beat me to it, a pretty detailed explanation for the rebuild of the fan unit, this post should be made a sticky or whatever, brilliant work by the guy concerned.

As an alternative, electric fans are available for the Fourtrak. Kenlowe, have supplied a few and detail them on their web site.

Edward (ews) '92 Fourtrak 2.8 TDX

viscose fan

thanks for all your help.
its a sportrak 1600 16 valve g reg carb model.
as soon as i got in from work tonight , i tried the cardboard method
and locked up the fan that way,
then i came in and then read your helpful posts.
i will try to refill it with the silicone oil at the weekend and will let you know the results.

it didnt look that deep !!!!