300 detune

[jb_dallas]

I have a 2011 GasGas 300 six days and just bought a 2013 KTM 300XC. I still love the bike,but resale isn't great for GG,so I've decided to keep it. It's really a great bike. My issue is that I have friends with different riding ability. One friend has plenty of experience and can handle the power fine....he is just broke and had to sell his bike. My other friends probably belong on a beginner bike, like a XR or DR. What can I do to tame the power besides a fww? I thought about jetting it a bit rich...but I'm not sure that would be effective enough.

Thanks

 

[djroggen]

Fww. Seriously. Get the big s3 weight. You will be pleasantly surprised. Don't jet it rich.

 

[andoman]

Raise the stock gearing. It will tame things by spreading the powerband and slowing down the rev rate.

Slightly richer jetting is very helpful, but don't jet it rich for richness sake. Search around the jetting forum and go with a needle that gives a smooth delivery in the mid-range and a smooth transition on to the main.

If you really want to make it rideable like an XR or DR then figure out how to put a simple throttle stop on it. A spacer on the top of the slide to limit how far it would come up would do the job.
I can't imagine an easier bike to ride than a 300cc 2t with a limited top end and smooth power band.

 

[Stoby]

careful

I'd keep any kind of beginner off a 300 2t. Not really the advice your looking for but you don't want your friend f'ed up. I don't think you could make the bike safe enough fww jetting pwrvalve its still a big torquey 2t thatll throw you on your head. Plenty of experienced guys think a 300 is a handful

 

[Bandit9]

I'd keep any kind of beginner off a 300 2t. Not really the advice your looking for but you don't want your friend f'ed up. I don't think you could make the bike safe enough fww jetting pwrvalve its still a big torquey 2t thatll throw you on your head. Plenty of experienced guys think a 300 is a handful

Roger that. I even made a comment to my buddies today after we came out of a tight section. I said, "you know a 250 is probably perfect". The Gas Gas 300 motor is a lot of motor, even for me at 6'1 233lbs and tons of experience.

 

[Jakobi]

Raise the stock gearing. It will tame things by spreading the powerband and slowing down the rev rate.

Slightly richer jetting is very helpful, but don't jet it rich for richness sake. Search around the jetting forum and go with a needle that gives a smooth delivery in the mid-range and a smooth transition on to the main.

If you really want to make it rideable like an XR or DR then figure out how to put a simple throttle stop on it. A spacer on the top of the slide to limit how far it would come up would do the job.
I can't imagine an easier bike to ride than a 300cc 2t with a limited top end and smooth power band.

+2

This would be my first port of call. Taller gearing will really spread things out, but may make take a little more clutch work in the slow and steady. A flywheel weight will help counter this and also take some bite out of it.

Restricting the throttle would really dull it down I imagine and limit the damage when taking an unexpected handful of throttle.

As far as people riding it, I guess thats up to you and them to evaluate their abilities and confidence. I wouldn't put someone green onto one, but as long as the rider has the basic skills they shouldn't have an issue. Trying to ride a 300 like a 125 is when you really notice how much of a handful they can be.

 

[pscook]

G2 throttle tube. Mild to wild with the swap of a cam.

 

[nambo-trev]

G2 throttle tube. Mild to wild with the swap of a cam.

This is the best and easiest mod to take off something on a 300. You can make it as tame or wild as you like in a few minutes.

 

[Caravan Monster]

An extra spacer in front of the reed valve block will slow it right down. Easy to handle modern bike much more confidence inspiring for a beginner than a heavyweight '80's air cooler. Worked on a dr350 recently; surprised when I was reminded how heavy they were!

 

[nokturnal]

What about a different needle too? The CCK needle really took the edge off of my JD-blue needled bike.

 

[jb_dallas]

Thanks for the replies

 

[Eric K]

A few additions...

Add an extra shim to the power valve so it opens at higher RPM. It really mellows out the mid range.

Put a restrictor washer between the exhaust header pipe and cylinder head. You can really mellow it out with a smaller opening. This option is simple and low cost.

 

[Coop]

G2 throttle tube. Mild to wild with the swap of a cam.

This is the best and easiest mod to take off something on a 300. You can make it as tame or wild as you like in a few minutes.

Not to derail this thread, but do these really make a difference? I had bicep tendon surgery this year and have trouble with throttle control now when the power comes on even on my 250. I am going to do a couple things to smooth it out even more over winter and this is on my list if it really helps. Is it just barely noticeable, or an honest noticeable difference?

 

[Bandit9]

Coop, it is very very noticeable on the 400 cam.

 

[Stoby]

g2

the g2 works.
http://www.gasgasrider.org/forum/showthread.php?t=116&page=2

kind of controls the first 1/8 -1/4 slows it down almost imperceptibly to me but its there. Can't feel it exactly but it works

Dont think it makes a 300 safe for a newbie but...........

 

[Moto7man]

You could try some type of throttle slide stop like Yamaha uses on the WRs. I don't think this FCR Carb design would be applicable to a 2 stroke. You could probably install some type of slide stop limiting it to 1/4 to 1/2 throttle.

WR design
http://www.thumperfaq.com/throttle.htm

 

[gasser]

Cheapest and best way to tame a 300 (imo) is to change the carb needle. I tried the CCK needle in my 300 and it did work better down low but made my bike a gas hog. I have a Suzuki needle in my 250 and it works fantastic for slower riders - power comes on slow but very strong - makes the bike very easy to ride.
2nd mod I would make is not as cheap (@$100) but almost as effective and that is the G2 throttle with a #400 cam. That will instantly make a 300 as controllable as a 250 (with standard throttle) off the bottom.
3rd mod doesn't cost anything - tune the bike a little rich. You can even tune a gasser a lot rich before it starts fouling plugs.
There's a reason all 3 of these mods have been suggested by others - they work. These 3 mods (@$130) can tame the bottom end of the mighty 300 and make it almost as easy to ride as a 4stroke without killing the 2stroke fun factor.

 

[Zman]

You can also retard the ignition timing. This will make a big difference, only takes a few minutes and it is free.

 

[Jakobi]

I haven't tried any of the G2 tamer cams but I can tell you the quick pull made a very noticable difference.

Good thinking re the timing. Not too hard to pull the flywheel and retard things a bit.

I still think a throttle stop is the 'safest' method. Everything else works to smooth out and tame the delivery of the power, but the stop will actually limit the total amount of power that can be delivered. Smoothing things out will help reduce the chance of the rider taking a handful an getting spat off unexpectedly, however when they hit that bump, half fall off the bike and hang on with the throttle pinned it'll still be a 300cc 2 stroke on song.

 

[Zman]

To adjust the timing you only need to remove the ignition cover to get access to the ignition / timing plate and mounting screws. There is no need to remover the flywheel. Loosen the mounting screws, rotate the plate in the same direction that the flywheel normally rotates and then retighten the screws. I would try moving the timing plate about 0.1" (measured at the screws) which should retard the timing roughly 6 degrees. Mark the original timing location before you loosen the screws so you can put it back later.