Hard hit

[2stroke yz]

Hey all, I have a 92 YZ 250, 2 stroke. It's got a fresh cylinder, weisco prolite piston, FMF powercore 4, boyesen reeds and every time I get to about half throttle it just points the front end straight at the sky. I'm new to dirt bikes, so is this pretty common? If so how do you hit full throttle and not pull a wheelie? I was looking at putting a 13oz flywheel weight on it. Chuck Steahly from steahlyoffroad said that the 13 oz would make the power a little more manageable. Any advice? Thanks in advance. :whoa:

 

[IndyMX]

use the clutch to control the angle of the front end... ;)

 

[FNG]

Yes this is normal, get your weight forward, the flywheel weight does a good job of spreading out the power but it will still have the hit. With the flywheel weight it will help you be in the next higher gear to get you out of the "wheel house" of the motor until you get better. Also getting your jetting right helps the "rideability" of the bike.

Being new to the dirt and jumping on a 250 is definately going to challenge you and you just might find it to be too much.

I have many, many years of 3 and 4 wheelers in my past along with 30+ years of snowmobiling and my 95' YZ250 is still a handfull after 2 summers on it. I have no idea how someone could use all of the power it has on an MX track, let alone for 10 or 15 laps but it is a lot of fun trying.

Get a shop manual for it so you can better understand the suspension and how to adjust it. I spent quite a bit of time on mine before I found how I liked it and it really helped my stamina and control.

 

[helio lucas]

wheight tranfer is a basic skill in mx. to keep you front end down just lean front and to get you back tire to bite (grip) just lean back...
a lower compression ratio may help to tame the hit.

 

[sr5bidder]

a 250 2 stroke is a handfull especially to learn on. I have a buddy who is doing just that, its amazing how well he is doing but he has been hurt several times

his is an89 yz250

 

[YZ__rider]

A 250 2 stroke is not a beginners bike. You would be better off learning basic riding skills on a more tame bike, such as a 250 4 stroke trail bike. Once your skills improved on the 4 stroke, you could have moved up to a 250 2t. You skipped the training step. To answer your question, you should be sitting as far forward as possible.

 

[2stroke yz]

thanks for the replies guys. I only had a stash of cash in my gun vault the my wife would let me use and I couldn't take on another payment. Around here there wasn't much in terms of decent used 4 strokes that hadn't been abused. It is a lot of bike, but am down for a challenge. It's also tough since I haven't taken it onto a trail or wide open field. I think between the flywheel weight and some serious practice I will atleast be able to make it a little more manageable. I haven't had any problems with the back tire spinning probably because I'm just nursing out the clutch when I start.

 

[IndyMX]

Don't treat the clutch on your bike the way you would one on your car.. They aren't the same..

The clutch on a race bike is meant to be slipped..

They way I was told, and I never claim to be an expert, was that you pin the throttle, and use the clutch to apply the power. Where you can control the power with the throttle on a 4 stroke, you control it with the clutch on a 2 stroke.

Your clutch will definitely wear out faster this way, however, it's how the bike was designed to be ridden.

It should also help you keep the front end on the ground a bit better.

 

[scottiedawg66]

that sounds normal. I recommend trying some of these

http://www.motionpro.com/motorcycle/search/by_motorcycle/revolver_throttle_kits

 

[TWRT]

Another thing is that you have to learn to anticipate the acceleration (or 'hit'). Leaning forward and gripping with your knees/feet/legs, just before the 'hit'...

If power comes on and you are not ready, you get thrown backward which weights the rear tire and unweights the front end and up you go. As you get better at riding, you will find that this is similar to the technique used to purposely do a wheelie.

practice. get seat time. Do not grab a handfull of gas until you have many hours under your belt. Wear plenty of equipment..

Dave

 

[whenfoxforks-ruled]

If it was not for 2 stroke MX racebikes, where would crash videos on u tube be? Get the manual, it may have the adjustable type of exhaust valve to lessen the hit in the power band. You may get used to it, and maybe not? Like Helios said, detune it by lowering the compression or taming down the port timing, more like a trail bike. Grip the bike with your legs, sit almost on top of the tank, and keep it pinned! Till its time to slow down, that is kind of important. The seat is for looks, not sitting. Suspension set up and gearing can effect the wheelie thing also. Vintage Bob

 

[01HondaCR]

+1 to Indy, I tried the throttle only on my old 2001 125 (my first big bike) and i was getting jerked around, didn't feel comfortable, and was just all over the place. After i learned the whole pin it and feed the clutch out of corners technique, it made a world of difference. I was faster and felt way more comfortable.

 

[Joburble]

Are you planning to trail ride this bike or MX race it?

 

[2stroke yz]

Thanks for all the tips guys, im going to look into a more conservative tune along with a flywheel weight. Im primarily going to be riding trails and a few home made mx courses, no real races for me. Im 6'2" and 210 lbs. In terms of gear i am always going to be wearing a chest protector and a helmet, do mx boots make a big difference? You guys know your stuff, i appreciate you helping me not kill myself on this thing.

 

[Joburble]

In regard to boots, yes, get yourself some dirt bike boots. However, some boots just about immobilise your ankle and in doing so they transfer loads to the knee (not good). As you are mainly riding trails get some boots with a reasonable amount of ankle movement. Get some knee guards too or even better, knee braces. Neck braces are a good thing too, they are only expensive and cumbersome until you wish you had been wearing one, IMO.

In regards to the bike you could try putting a couple of base gaskets in it, that would lower the compression ratio and I think change the port timing to give it more bottom end. (Others comment on this please just in case I am mistaken).

 

[helio lucas]

try putting a couple of base gaskets in it, that would lower the compression ratio and I think change the port timing to give it more bottom end. (Others comment on this please just in case I am mistaken).

in reality with thicker base gasket the timing are more agressive, they shift the power upper on the rev range. the ports open sooner and with lower compression it takes away the hard hit, smoothing out the power delivery. :cool: