240 Discssion

xjma

Member
I searched. Way too much stuff comes up about 240!!

I'm not really interested in upping the displacement myself, I'm more just wondering what everyone's opinions are about it, and why it seems like such a popular thing to do.

I understand that "there is no replacement for displacement," but do those 40 extra CCs really give you that much more power?? Everything I read is just "I want 240, which is best" and stuff like that. No discussion of plus and minus of 240 kits, etc.

Basically, can someone explain the me the logic behind the 240 kits? Does it just give an across the board increase in power, or does it target a specific RPM range?? Is it better for general trail riding or racing?? And how much does it decrease the reliability?? Also, it seems like you need a larger carb for the kit too....
 
Well, alot of people will tell you, a stock 240 kit, especially a vitos, will not be an amazing upgrade and a custom Port and polish is the best power for the money you spend. and its right. but getting a 240 kit AND a port and polish will most likely make you sh*t a brick. plain and simple.
 
I searched. Way too much stuff comes up about 240!!

I'm not really interested in upping the displacement myself, I'm more just wondering what everyone's opinions are about it, and why it seems like such a popular thing to do.

I understand that "there is no replacement for displacement," but do those 40 extra CCs really give you that much more power?? Everything I read is just "I want 240, which is best" and stuff like that. No discussion of plus and minus of 240 kits, etc.

Basically, can someone explain the me the logic behind the 240 kits? Does it just give an across the board increase in power, or does it target a specific RPM range?? Is it better for general trail riding or racing?? And how much does it decrease the reliability?? Also, it seems like you need a larger carb for the kit too....


i know what you are saying, there are pros and cons of it, i haven't done it but i plan to if i ever fry my blaster, but if you do it you have to do it right or you will be rebuilding your bike every weekend after riding, you need a upgraded crank shaft, i would go with a 4mm stroker, wiseco preferrably, i would put an iridium plug in it, advance the timing, at least a 34mm carb, and go with the v force reed cage assembly, 1/2" spacer, also have to port and polish, resleeve the cylinder, i can go on forever this is just stuff i know of and would do to make sure it ran right, oil block off, but most people do this before they do the 240 kit, it is a lot of work and yeah it does do quite a bit, ridden my buddies and it hauls, the blaster is really light, i have seen people go as far as 60 over,which i think is kind of ridiculous. thats what i think.
 
from what i hear, its supposed to increase a mostly in the low to mid range. i've heard of overheating problems with them. and as far as a bigger carb goes, a stock blaster needs a bigger carb. lol. i'm pretty sure stock yz 125 carbs are bigger than 34mm.... 75cc's less, with a 8mm bigger carb. hmmm
 
72mm piston versus 66 is a huge difference its actually only a 232cc ,there will be a substantial amount of torque gained over a 195 cc and yes most of that will be felt in low-midrange power ..the peak rpms probably wont increase ,big bore or not ..porting is where the power is at
 
yup. porting is where true engine power is gained. this is where the dynamics of the engine itself are tuned. just adding bore displacement will give you bottom end, but it's almost just bolt on type power. not true engine performance upgrade.
2smoker's right about a couple things; you will not get the full potential out of the 240 kit (or even the stock bore blaster for that matter) w/ the stock carb. you can run the stock reed cage, but throttle response will suck. and i doubt that the cage spacer really does anything. you don't necessarily need to upgrade your crank just for the 240 kit. if you stroke, don't do the 4mm over, go w/ the 3mm over. it's actually better. if you stroke the motor, don't rob yourself by using the jug spacer. get the port and head work done by a good machinist. you'll be much better off.
basically the 240 kit is good, but not great. port and polish is def great on any bore blaster!
 
The Vito +3 stroker crank will fail you if you push your motor hard, unlike the +4 Hot Rod. The Vito crank has ground off the bottom of the rod in order to fit it into the crank pocket and this is where I have been seeing the failures.

It has got so bad that I question the customer as to how hard the engine is run and if it is to be raced, I refuse to install one unless it is agreed that when the cranks takes a dump, I am not responsible.
 
The Vito +3 stroker crank will fail you if you push your motor hard, unlike the +4 Hot Rod. The Vito crank has ground off the bottom of the rod in order to fit it into the crank pocket and this is where I have been seeing the failures.

It has got so bad that I question the customer as to how hard the engine is run and if it is to be raced, I refuse to install one unless it is agreed that when the cranks takes a dump, I am not responsible.

i have that +3 crank, and run the hell out of it, is it possible they changed the rod, only because i had to grind the two case halves so the bottom of the rod didnt hit the case, oh yea have u seen alot of these break?
 
They have thinned out the bottom of the rod so there is no actual machine work to the case halves to install the newer cranks. There are those that will argue that the material on the bottom of the crank isn't needed but, after seeing the carnage that happens to a race motor when one of these let go, I say it does make a difference.