YZ426 Blaster

[flotek]

yo u should really consider a keihin 39mm pwk d slide carb ,a much improved carb over the oldschool vm carbs ,theyre only good for small displament engines ...another mod yo ureally could benefit form is a full race port not just a polished exhaust tract ...that wont do anything for power ,yo umust rememebr then in the 70's the 2 stroke pipes and port designs were really lousy and crude ,you could get a huge power increase by getting it fully ported for all around nuts with the help of modern port mapping software ,with the right setup theres no reason that motor shouldnt be making a true 60 horse and 40lbs for torque at the rear wheels .

[Paulie B]

Originally Posted by carl250r

good read on that blaster build up.

that bike is going to be cool with the old school yamaha yellow colors.

i remember that RC car from back in the day. wasn't it called a jack rabbit?

Yup. It's about 15 years old. Things made of metal last longer than plastic Pretty much only the chassy, cage, and tranny (I even changed the gears) are from Raco. I do have the body but only for show. They are too rare to drive around with.
I've always like the old school yellow Yamaha colors. Reminds me of seeing them when I was a kid...PB

[Paulie B]

Originally Posted by ky 2stroker

man that motor looks gorgeous looking. that thing should be in a glass case in a museum lol

very nice work

Thanks man!

[Paulie B]

Originally Posted by eviltwin

yo u should really consider a keihin 39mm pwk d slide carb ,a much improved carb over the oldschool vm carbs ,theyre only good for small displament engines ...another mod yo ureally could benefit form is a full race port not just a polished exhaust tract ...that wont do anything for power ,yo umust rememebr then in the 70's the 2 stroke pipes and port designs were really lousy and crude ,you could get a huge power increase by getting it fully ported for all around nuts with the help of modern port mapping software ,with the right setup theres no reason that motor shouldnt be making a true 60 horse and 40lbs for torque at the rear wheels .

Flotech, hmmmm you guys could lighten my flywheel???
I've thought about porting. 2 reasons why I haven't.
426cc's is the absolute max my cylinder can go. I'm afraid of spending money on a cylinder that gets thrown in the trash after it wears out. The other reason is the stroke of my motor is 75mm. If I remember right that's more than a CR500. I think that huge stroke kinda limits my rpm and that's what porting does for a motor right basically lets the motor breath better @ a higher rpm? I'm just guessing here. Your right about the ports. They are rough.
The 39mm Keihin pwk is the carb I had in mind, either that or a FTZ alcohol carb.

[flotek]

Originally Posted by Paulie B

Flotech, hmmmm you guys could lighten my flywheel???
I've thought about porting. 2 reasons why I haven't.
426cc's is the absolute max my cylinder can go. I'm afraid of spending money on a cylinder that gets thrown in the trash after it wears out. The other reason is the stroke of my motor is 75mm. If I remember right that's more than a CR500. I think that huge stroke kinda limits my rpm and that's what porting does for a motor right basically lets the motor breath better @ a higher rpm? I'm just guessing here. Your right about the ports. They are rough.
The 39mm Keihin pwk is the carb I had in mind, either that or a FTZ alcohol carb.

sure it could be lightened .the big displacement single engines tend to rev slow and a lighter flywheel is a nice benefit to get some response and higher revs . 75mm isnt clsoe to the stroke of a cr500 . proepr porting will allow the engine ot breathe better at all rpms ,wit h a 400cc single yo u could have awesome lowend and plenty of topend punch . it isnt so much the flaws and poor casting but also the durations and shape and angles of the ports will make all the difference ,yo u can port it for a target rpm to produce a very wide powerband .i would think for a 79 you could literally double the stock power output by porting head mods and a bigger carb.

[Paulie B]

Now you got me think'in.
How long will my fresh 426 cylinder last on it's last overbore?
How much would such a port job cost??

[flotek]

well im not sure how long it would last thats up to yo u and the maintenance on it ,might only need freshened up then later maybe a hone ,,hell might go for a long time . i usally dont discuss my prices in the open forums . i wll send you a pm instead

[Speedy2222]

let me know if u wanna get rid of those front tires

[Paulie B]

Originally Posted by Speedy2222

let me know if u wanna get rid of those front tires

Let me guess, you want to make a midget tire swing

[Speedy2222]

actually i want em for a project i am doing.. ssoo let me know if u wanna get rid of em