kx 65 for beginer

[wayfastwilly]

In july i bought my 6 and 10 yr old boys a crf50(88cc) copy and a crf 70 (110cc) copy. The bikes were cheap so i could see if dirtbikes was something they would be interested in. Boy did i hit paydirt, its all they want to do. I even bought a used 91 yz250 so i could ride the tracks with them. Yea, after riding real tracks, the yard, open fields and trail wont do, its big jumps and high berms for them. Anyway, their first race was jan 8th at burnthill motox in brookland AR, and Will(6) a 3rd and 4th, 4th overall in the PEEWEE50 class, and Taylor(10) took a 3rd overall in the 65 beginner two stroke class, I WAS STOKED! The 50 is okey, its a good size and power for a 6 yr old, however the 110 sux, the only way he got 3rd was by staying on 2 wheels the whole race. I couldnt sleep at night knowing even if he rode at pro level he still coulnt keep up with the beginners on the 65 smokers.SSOOO, I sold the 110 (and got my money back!) and bought a 2004 kx 65 for $700 with a siezed engine (ran STRAIGHT gas for about 100 ft) put $600 in a hot crank/rod combo, wiesco piston kit, a lukes racing replated cyl, including labor. Now the bike is running and broke in, and the powerband has a wicked upper mid/topend hit. My son has only ridden it about 3 hrs so far, but it scares the hell out of him when it comes on the pipe.Finally to my question, What could i do to soften the power a little? Dont get me wrong, he is no wimp, Its just he is coming off of a 6hp 4spd auto clutch, to a 13hp 6spd manual. He has a lot on his plate. Gimme a clue, reeds, pipe, a combo of the two? All input will be appreciated! Sorry for being long winded :blah: , but my boys are my pride and joy. PS will smoked taylor in a 2 lap race today on on the hopped up 50, thats how cuatious taylor is being! THANKS ! :)

 

[TimberPig]

Unfortunately, that is pretty much the nature of a small bore MX 2 stroke. They hit hard and need to be revved to make power.

A set of reeds might sharpen the throttle response a tad, but it isn't going to soften the hit much.

A pipe could be built to smooth the hit, but you would have to research the characteristics of the pipe. Many are designed to make more power, rev higher, and they actually hit harder too.

A flywheel weight would smooth the sharpness of the hit somewhat, but the bike will not rev as quickly. This is normally the best option to smooth the power delivery. A bolt on weight could be removed once he has become more confident.

Rich jetting can also make the hit more sluggish, but the bike won't respond as cleanly, and will be a plug fouling beast as well.

The main thing is though to get him as much seat time to get confident on it. The more he rides it, the less he will be afraid of it. Once he gets used to it, his little brother isn't going to be able to beat him anymore. This may mean you need to take him back to the fields and let him run up and down them to get used to it in an environment where he doesn't have to worry as much about jumps and stalling. Get him used to it there, then take him back to the track. Trying to get confident on a new bike that scares you, and concentrate on racing is unlikely to be a successful venture. He needs seat time to get used to the bike, and then he can get back to the racing.

 

[wayfastwilly]

great answer!

That is exactly what i did today, the track was too wet to ride so we went to a park with a huge open field. He putted around letting his brother run off and leave him, until i begged him to trust me that the bike would not just shoot out from under him if he hold the throttle open. He went out and got the bike straight and in 3rd gear and pinned the throttle and shifted through the gears. He was blown away, he had a blast. A little confidence goes a long way. Thanks for replying, this is a awsome forum with some cool members. I do think i may go with a boyseen duel stage reed, cant see where that would hurt. :)

 

[FruDaddy]

You might also try teaching him to control the speed with the clutch rather than the throttle. Pin it and fan the clutch. This way he controls the hit and there is no sudden assault.

 

[Jasle]

goe up one tooth on the front sprocket. it will lessen the hit a good bit. If you want to spend a few bucks I can send you info on how to mod your stock pipe for more bottom. you'll need a fabricator guy that can do the sheetmetal work. Also having Eric Gorr do the porting can help quite a bit. Plus he's pretty reasonably priced.