9 replies to this topic

[graham5170]

Hi guys
early xmas for my 5 year old
i have just bought a wee gas gas 50 from <mention of this company is not permitted on Trials Central> the little 2 speed auto one
can anyone give some info in this bike for looking after it
what is the pre mix ratio etc
any info would be great
i tried to do a search but the site is not letting me do one ????

[Telecat]

There is a link off the Gas Gas UK website to the US pages of two guys who have the answers to virtually any question on Gas Gas. In this case they recommend 66:1 premix ratio. Or about 75ml of oil per five litre can. Tony will have a little jug that allows you to see the amount of oil by Mix ratio for a litre and 5 litres as well as just the amount.

Edited by Telecat, 12 July 2010 - 12:39 PM.

[faktree]

Graham.

When I had a TX Boy for my lad we run it at 80:1, that is about 60ml of oil to 5 litres of fuel. If you put any more than that in it will smoke alot, fill the tailpipe with oil & start to spray oil from the tailpipe all over the swingarm & rear brake if you dont rev it much... Use any good quality 2T oil apart from Silkolene, its too thick, eventually it will stick the piston rings in & you won't be able to start the engine!

Stick 150ml of a light gear oil or a 10w30 motor oil in the gearbox & it should be fine....

If my memory is correct I fitted a bigger rear sprocket to slow the bike down, I think it was a 60 tooth!

What else do ya need?

Faktree...

[Telecat]

Don't know If Joe Faunthorpe's Dad lurks around here anymore but if not and I see him I'll see what he recommends.

[juanroberts]

I just bought two used TXT Boy 50s, an 01 and an 05. I put the rear spring in the softest of the three clip settings, and took out the spacers in the front forks, and that works much better for my 5- and 7-year olds. I short circuited the temp gauge that is above the motor so that the fan will run non-stop, just in case.

I am going to try the thicker clutch plate trick. I also noticed the gas tank valve did not really work, so will try to order a new one. Does anyone know if a rear brake and clutch master cylinder's rebuild kit is available, particularly in the USA?

When the rear wheel bottoms out on both bikes, it rubs against the top of the mudguard. Is there an easier fix than bending the subframe?

Thanks.

[MikeID]

Hi John:

Yep, I think they're available here.

Mike

[smudger984]

Hi

To Juanroberts:

"..... I put the rear spring in the softest of the three clip settings, and took out the spacers in the front forks...."

Can you expand on this as my boy struggles with the size of his bike its an 09 model. I have lowered the forks in the yorks, but can you explain the softest of the three clip settings, and what is involved in taking the spacers out of the front forks?


Graham5170: I have also put the a 60 tooth rear sprocket on my boys bike and its loads better, it pulls away slightly better on low revs and does slow it down a little, as soon as I did this he was able to do stood up turns so much better !!! also I run my with the same oil and premix as my 250 pro just because it saves on having two cans, 75ml to 5 litres and yes the bike does smoke a little but not a lot, but I do get oil coming out of the rear pipe which does go everywhere, but I dont mind this and my little boy does rev the thing up !!!

Cheers

[juanroberts]

smudger984, on Aug 4 2010, 12:46 AM, said:

Can you expand on this as my boy ...

FORKS: Take off the handlebars. If its like the earlier models, then remove the rubber caps on the top of the forks. Finally, push in the white plastic caps and you will see that a circlip ring snapped unto a ridge inside the fork tubes are what keep the white caps from popping out. While pushing the white cap in (down), remove the circlip with a small screwdriver. There was rust there that I removed with a rag. Below the white cap is a plastic tube that is about 4 inches in length, and below that is the fork spring. Remove only the plasting tube, and reassemble. Do both forks. The sag on the forks will be altered by about 3 inches as a result.

SHOCK: Remove the shock. Use at least 3 fullsized vise grips (pressure pliers) at evened-out spaces to compress the spring along its length, i.e., clamp them between spring coils so the spring is compressed and not at full-length. Be very careful since the pliers can snap off at any moment, push the spring down and you will then hopefully notice there is a shaped/flanged/L washer with a circlip seemingly inside of it but its on the shock body keeping the spring from coming off. There are three grooves for the circlip, and the stock setting is in the middle of the three. Set the circlip in the soft position (farthest away from spring). It makes a huge difference once you get on the bike and try it. This should be enough, and if it is not, you can always cut some length off the spring, and put some rubber tube over the ending coil so it centers on the shock body, but that would be a last resort in my book.

This is what it looks like when a loop in the shock spring coil is also cut off:


The suspension on the Gas Gas 50 is the best, and the large wheels make for a very stable bike when compared to an XR50R. I may be wrong, but the forks seem to have no compression dampning.

[smudger984]

Hi Juanroberts


Thanks for the info !!!!!!


I will do the forks for certain, the rear shock seems to be quite awkward to do will speak to mate as hes a better spanner man than myself !!!

Thanks once again !!

[smudger984]

Hi Juanroberts


I have completed both the front and back suspension adjustments.... Took the spacers out of the forks and set the rear to the softest setting.

My thoughts ....

The bike sits much lower but dosent look silly and my boys feet are now firmly planted and the bike looks the right size !!!!

The front forks were easy to do but the rear suspension was a bit harder, we had a proper spring compressor tool but still had to also use a vice to get the spring to compress enough to move the circlip, glad I've got mates who know what they are doing.

Thanks once again for the advice

Cheers

Smudger