can anyone help i am about to strip my sons 125 pro (03) to have a look at porting etc see if i can give it a bit more power (he is a big 14 year old), has anyone any experience of what works best, also does anyone know where to get reeds for pro, boyesen for example and do they make any noticeable difference, i was also thinking of putting some in my 05 300.

thanks jeff

Put a keihin carb on and exhaust system of the 280, you will lose a bit of bottom end but it will rev to the moon.

Can't see you gaining much by just changing the reeds.

Keep us posted on your results my son also has an 03 125 pro. I have installed Boysen reeds in his bike, I don't think it makes any more power but it really makes the power smoother. I have been using Boysen reeds in all the GasGas bikes I have owned. I have them in my 02 Pro and they really help smooth out the power. I always cut the reed stops off just above the retaining screws and have never had a reed failure

I always cut the reed stops off just above the retaining screws and have never had a reed failure

Do you mean you cut all the radius off the stop plate or something else?

Sounds a bit dodgy to me

Cheers

Chris

thanks for replies,

will keep posted on results with tuning of 125, (has anyone noticed how well alexz wiggs 125 seems to perform) ps where do i get boysens for the pro

Most Boysen reed sets come with a new mounting plate the ones for the Pro do not. All the reed mounting plates supplied by Boysen do not have reed stops[curved metal fingers that extend up behind the reeds]. I cut off the stop fingers and smooth out the area on the mounting plate with a file. I know that I'm not the only one doing this because I have had one of the bike that the US importer had ridden and he did the same thing to it.

I am also a big 14 year old lad, i would like more bottom end power as i have mentioned on here possibly a thousand times, i just want it to be right on with the power, like faster reaction.

So thanks for keeping us posted

Richard

will keep you posted, havent had reply from anyone yet telling me where i can get reeds from, will be 1-2 weeks before i get chance to do anything with bike.

Wouldnt the obvious be to get the cylinder and piston for the 200 pro be the answer? yes it would only kind of depend on the conditions of engines you are currenlty at, I mean, if it needs anything other than rings, I would go for the bigger jug&piston, I am half sure rest of the engine is zactly the same?

least it was told to me they were on the txt's, and in fact that is why I bought the 10 year old (he'll be big soon) the 200 because same bike with the 280 jug& piston could easily be done cheaper than a new bike...

but who knows I could win the lottery by then and we'd all have new 4strokers, NOT!!!!

Edited January 20, 200521 yr by Sting32

havent had reply from anyone yet telling me where i can get reeds

You need to find a local Boyesen dealer I think they are distributed by Serval Marketing (AXO Sport) 01234 365365. Looks like you need the #659 reeds.

I have always had to do a bit of running round to find Boyesen's, give Cusworth's in Doncaster a try, or most MX dealers (stocking AXO stuff) can order them for you.

Edited January 20, 200521 yr by Subira

Wouldnt the obvious be to get the cylinder and piston for the 200 pro be the answer?  yes it would only kind of depend on the conditions of engines you are currenlty at, I mean, if it needs anything other than rings, I would go for the bigger jug&piston, I am half sure rest of the engine is zactly the same?

least it was told to me they were on the txt's, and in fact that is why I bought the 10 year old (he'll be big soon) the 200 because same bike with the 280 jug& piston could easily be done cheaper than a new bike...

but who knows I could win the lottery by then and we'd all have new 4strokers, NOT!!!!

The rules in the UK mean that 14 year olds have to ride a 125.

A class is going all 125cc very soon so thats up to 17 years of age.

I can't remember the ruling but think that 125cc is being phased in under UEM rules up to 18.

It would be wise if thwe Americans ever want to produce the next Bernie or Lane (did I say that, excuse me) then in the States they should follow suit.

IMHO: This CC restriction is rediculous.

&

thank (your deity here) that it isnt enforced here in the US...

(I removed most of my reply, since it has nothing really relavant to the OP's topic...)

Edited January 24, 200521 yr by Sting32

Try Haven Trialsport at barrow haven (near barton) they will be able to get you anything you want for your gasgas, and offer advice on upgrades. call them on 01469 532600

More power for the 125cc easy.

Change the timing.

Take the jug off have the base machined down approx .005>.010.

Take the carb off, put a sleeve in it to take it down from 26mm to 24mm or even 22mm.

Do not use Boyseen reeds as the will take away your bottom end on a 125cc big time. This is due to the reeds being predominatly made for a 250cc and the little 125cc does not have enough vacuum to open the big reed efficently.

As for the removing the reed stops, DO NOT REMOVE THE REED STOPS ON ANY REEDS>>PERIOD>

The pro motocrossors have their engine rebuilt every race or two therfore the engine rebuilder can check for cracks or fatique in the reeds. There by letting them remove the reed stops. Trials riders very rairly rebuild their engines so any problems with the reeds will not be noticed.

The stops are there for a reason and the general guy thinks he knows better and removes them. Believe me when I tell you I have seen several trials engines were the guy removed the stops and the reeds eventualy cracked. When this happens the reed gets sucked into the engine causing very expensive damage.

Trials engines do not rev high enough to take advantage of any stop removal. In all reality you will lose perfomance in a trials engine as the reed moves open further as it starts to flutter the further it opens.

Cheers

BillyT

Edited February 12, 200521 yr by BillyT