Txt Pro 2003 Spark Plug Gap & Carb Screw Setting?

[tyanything]

Manual for the Txt Pro 2004 gives the spark plug gap at 0.6.Is the Txt Pro 2003 the same?

Checked gap on the old plug which is 0.8 so could someone tell me the correct size?

Also how many turns out for the pilot screw on the carb?

Thanks.

[tyanything]

Manual for the Txt Pro 2004 gives the spark plug gap at 0.6.Is the Txt Pro 2003 the same?

Checked gap on the old plug which is 0.8 so could someone tell me the correct size?

Also how many turns out for the pilot screw on the carb?

Thanks.

Nobody know?

[motojojo]

The '04 pro takes a smaller gap than an '03 they have a different ing. I don't know the exact gap try gasgasusa and look up tech tips. And if all else fails e-mail Jon and he will know, and he can tell you what plug is best. Right now I would leave the plug alone and adjust the carb. First thing to know is what side of the idle adjustment screw is your flow adjustment on if its closest to the air filter it is a air flow and closer to the motor is a fuel flow. I think yours is a fuel adjustment , you lean that out by screwing it in. Start the bike warm it up have the adj. screw out 2 turns then rev. the motor and listen for how fast it goes back down, what you want is fast up and fast down, play with it turn in half a turn and rev the motor listen then go back out 1 turn rev the motor and listen then move toward the smoothest. Hope this helps.

Edited October 28, 2007 by gtgasgas

[tyanything]

The '04 pro takes a smaller gap than an '03 they have a different ing. I don't know the exact gap try gasgasusa and look up tech tips. And if all else fails e-mail Jon and he will know, and he can tell you what plug is best. Right now I would leave the plug alone and adjust the carb. First thing to know is what side of the idle adjustment screw is your flow adjustment on if its closest to the air filter it is a air flow and closer to the motor is a fuel flow. I think yours is a fuel adjustment , you lean that out by screwing it in. Start the bike warm it up have the adj. screw out 2 turns then rev. the motor and listen for how fast it goes back down, what you want is fast up and fast down, play with it turn in half a turn and rev the motor listen then go back out 1 turn rev the motor and listen then move toward the smoothest. Hope this helps.

Brilliant! Much appreciated.

[tyanything]

Emailed Jon and reply is as follows (in case anybody else needs same info!)........"The NGK BPR5ES is normal for the Pro but I run a BPR5EIX in mine. It's a much better plug and

worth the added expense. Set the gap at .6mm (.024"). The previous owner probably did not check

the gap before installing the plug.

Assuming you're near sea level, the jetting should be in the neighborhood of:

Main-107

Pilot-S36 or better, S38

Needle-D48 with clip on 2nd groove from top

Fuel screw- start at 3.5 turns out

Check float height, float should parallel with sealing surface on carb body

The Dellorto flatslide was only used on the 2003 Pro. Set your fuel screw

each time you ride to get the maximum response. Blip the throttle open and

closed quickly to check response and open/close fuel screw to give the best

pickup response."

[motojojo]

Jon knows his stuff plus he owns an '03. Hope its running better.

[scoobystu]

I've just bought a 2004 TXT Pro 300 and am having a few problems starting it. I think it is mainly down to my lack of weight on the starter right enough.

I read in the previous posts that if the mixture screw is closer to the barrel then it is a fuel mixture and closer to the air filter it is an air mixture. That may explain why I was getting some funny behaviour when I set the mixture screw to 1.5 turns it was all over the place. The screw I was playing with is closer to the barrel.

I gather it will only have one screw for either fuel or air mixture and not both.

There does seem to be some conflicting information as I have found a technical data sheet that recommends the fuel screw should be 2.5 turns out and the spark plug gap should be 0.9mm rather than 0.6mm as everyone else suggests.

This is my first trials bike but not my first motorbike and it would seem there are quite a few differences.

[peterb]

Hi scoobystu,

I set up the 04 PRO 300's with a D34 needle, the standard D36 is leaner and a bit too quick on pick up at low rpm. Set the pilot (fuel) screw 3.5 turns out from fully in and adjust from there. Needle clip position 2nd from the bottom.

Plug gap usually 0.9mm.

From cold, tip the bike right over to the left as this floods the carb and makes it easier to start.

Bye, PeterB.

[scoobystu]

Thanks Peter,

I have made a few changes as you suggested and it seems to be a bit easier to start now. I think I need to gain about 2 stone in weight as well tho!

[jse]

Hi scoobystu,

I set up the 04 PRO 300's with a D34 needle, the standard D36 is leaner and a bit too quick on pick up at low rpm. Set the pilot (fuel) screw 3.5 turns out from fully in and adjust from there. Needle clip position 2nd from the bottom.

Plug gap usually 0.9mm.

From cold, tip the bike right over to the left as this floods the carb and makes it easier to start.

Bye, PeterB.

Good idea, I'll have to try a D34 in a 300. One of the things I've done that seems to help with the PHBL's is to drill the starter jet out to a #80 (.80mm or about .031") which makes my 02' 280 Pro start second kick in any weather. The stock starter jet is usually a #65 or #70 and is located at the bottom of the floatbowl at the end of the little brass tower with an o-ring on it.

Jon

[peterb]

Hi scoobystu,

If the bike is a bit of a hand full, you can fit a slow action throttle (black tube) and a Hebo flywheel weight.

Jon, thanks for the starter jet drilling out info, they are usually a number 60 and drilling to 0.8mm is a good idea.

Bye, PeterB.

[jse]

Hi scoobystu,

If the bike is a bit of a hand full, you can fit a slow action throttle (black tube) and a Hebo flywheel weight.

Jon, thanks for the starter jet drilling out info, they are usually a number 60 and drilling to 0.8mm is a good idea.

Bye, PeterB.

Good adivice, from my experience all the Gas-Gas Trials models come with the "fast", white, throttle tube (it has a slightly higher ramp which will pull more cable per degree of rotation) and a black tube works better for floppers like me.

My 02' 280 has the Kokusan non-alternative ignition mapping so one of the ways I soften the throttle response is to run straight 110 race fuel, which has the effect of retarding the static ignition timing. The race fuel has a slightly slower flame front propragation (one of the ways it resists detonation) which results in a lower "IMEP" or "Indicated Mean Effective Pressure" (similiar to a lower static pressure at TDC during the ignition cycle). And, the "modification" is easily reversed. Here in the States, 91 octane is generally the best retail pump fuel we can get.

I've spoken with several riders who have fit the Hebo flywheel and they all have been happy with the results.

Jon