Jump to content

Chrisrhondda

2001 GasGas TXT 280 ADVICE NEEDED

Recommended Posts

Hi all i purchased a 2nd hand gasgas txt 280 and when i test drove it I noticed water coming from the pipe on the radiator and a lot of steam exactly as if it was overheating,  I asked the guy is this normal and he showed me the fan and said that it do stick sometimes as the bike hasn't been used for a while and he flicked the fan and all was fine after that.. However I gave it a full service on the weekend because it wasn't running right (when being ridden sounds as if it was hunting for fuel) so a mate of mine adjusted the air mixture screw to allow more fuel and the bike did start to sound a lot better.  So on Sunday we decided to take the bikes out all was well at first then the bike started overheating  and water was coming from the radiator pipe and the one on top of the head,  i tried to spin the fan it spun once or twice then stopped .  Also the engine was running like as if the kill switch was being pressed on and off and when trying to start the bike it would give an almighty backfire which to me isn't right ?  i tried to start it back up when i got home to no avail the odd backfire and that was it, I also tried again today it started but then cut out and again gave a big backfire like a shot gun going off. 

On a seperate issue it suffers really bad from clutch drag is there any fix for this or a way i can improve this so its not as bad.

Thanks in advance and i do apologise for the long thread

Chris

 

Share this post


Link to post
Share on other sites

If the engine has been allowed to overheat then the thermostat will suffer. Usually the high heat causes the wax in the stat capsule to escape and then the stat will no longer open causing overheating. My advice is to 1) lift the head and inspect the cylinder bore for excess scoring and signs of seizure. 2) check the temp sensor switch for the cooling fan. Do this with a multi meter set to continuity, meter lead on each terminal of the sensor. Hot air gun played onto sensor tip. Continuity should be made when temp hot. No continuity then sensor shot! 3)The cooling fan housing may be distorting with heat and jamming the blade, or the motor is worn. 4) The coolant should have anti freeze in it. Anti freeze raises the boiling point of water as well as protecting from freezing, if the mix is too weak or non existent then this will not help with the cooling. 5) Water pump impeller may be slipping on the drive spindle. 6) Thermostat needs changing, you would have already looked at this, to test it use a piece of wire and lower into a pan of water that is warm and turn up the heat. When the water reaches approx. 75 degreesC you see the thermostat start to open and be fully open by 86degrees C. Hope you don’t find anything nasty wrong with bike🙂 With the clutch drag, put that on the back boiler and sort the engine out first. Most trials bikes have clutch drag and owners have different ways and means of reducing or eliminating it! Start with the external operating mechanism parts clutch lever pivot first then adjustment check. Lube all items that you can, find out what oil the previous owner used, it may be wrong spec. You might end up striping the clutch down to do the job properly, cleaning burrs off of plate edges and clutch drum. I’m fairly certain there is a good amount of info in the GasGas section on this forum. 

Edited by section swept

Share this post


Link to post
Share on other sites

Thank you very much for your very informative reply much appreciated and i will now go through the process of each section and eliminate each item until I find out the culprit thanks once again for your reply 

Share this post


Link to post
Share on other sites

Fix the overheating first. Then pull the clutch apart. Chances are you need new friction plates.

Share this post


Link to post
Share on other sites

 

 

 

I’ve done 2 short videos for you to have a look at to see if you can hear what I’m saying regarding the missing, fan still not cutting in even off a 12v battery so gonna order a new one tomorrow and thermostatic switch 

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×