1984 IT490 Rebuild thread

[crazycart]

Thought i'd make a thread on my baby...

Im soon ordering a piston kit for it. I am also dong a mod to the head where you have to cut the squish band down 8mm at a 30 degree angle. Makes tuning a bit easier and gives a tad more top end. Im going to clean up the frame, replace kicker spring, and maybe a few more odds and ends..

The piston...The rings stuck and compression before it had time to punch all the way through

It may look like your innocent everyday dirt bike...but trust me, it ain't.

 

[jr dragster T]

Looks good.

 

[Ibnzmonkey]

I love me a good bike. 4 stroke?

 

[crazycart]

Nope...its a 1 banger 2 stroke.

 

[jr dragster T]

Nope...its a 1 banger 2 stroke.

One monster 2 stroke!

 

[Russ2251]

Bore is just under 3.5".
I've heard they can climb trees.

 

[Kenny_McCormic]

Bore is just under 3.5".
I've heard they can climb trees.

Any 250 2 stroke/500 4 stroke worth its weight in metal will climb a tree in low gear. This sucker has the power to escape the earths gravitational pull!

 

[crazycart]

Bore is just under 3.5".
I've heard they can climb trees.

Yeah these engines are monsters. Not too many dirt bikes will pull the front tire in top gear doing 70+

Anyway, the cylinder is in the shop getting a fresh hone. Cant wait.

 

[Kenny_McCormic]

Yeah these engines are monsters. Not too many dirt bikes will pull the front tire in top gear doing 70+

Anyway, the cylinder is in the shop getting a fresh hone. Cant wait.

It takes some serious balls to go 70mph on dirt, not to mention doing it on one wheel!

 

[jr dragster T]

I've got a 125 maxxed out at 50 MPH before.

 

[crazycart]

125's should be faster than that. My 78' KD100 will top out higher than that.

 

[Kenny_McCormic]

thats a 2 stroke....

 

[crazycart]

Well since this is a 2 stroke thread and 125 2 strokes are very common i would assume he means a 125 2 stroke.

 

[jr dragster T]

Lol no it was a 125 4 stroke.

 

[I like karts]

Yeah really. I've gotten a yz85 (lol) to 60 mph in 5th gear

 

[Kenny_McCormic]

I've gotten an F-11 250 to 20 mph in 3rd gear.

 

[jr dragster T]

I've gotten an F-11 250 to 20 mph in 3rd gear.

Isnt that kind if slow for 3rd gear? I hope you where kidding.

 

[ed1380]

no dirtbike here

 

[Kenny_McCormic]

Isnt that kind if slow for 3rd gear? I hope you where kidding.

My yard is maybe 100 yards, its a 5 speed and I was just checking to see that it would go through all the gears. That and the motor has blown crank seals and no air filter(no dust to worry about for such a short trip over frozen ground).

 

[BradenM]

I had a Suzuki R450 up to around 85 km/h. Ran out of space, and scared owner. Rode for first time day before that.