03 blaster 240 vitos bb..

[Jgmblaster03]

Hey guys, im new to the forum. Recently just bought my blaster back i sold in 2005. 11 years of sitting i changed oil gas and all the good stuff. Started right up but after rising for a half hour it overheated and shut off. Got it towed jump started it on the way and it ran till about a minute from my house and it started knocking. Read forums on here saying piston slap. So i took off the head and cylinder and sure enough the piston was done. Everything has no issues. Sleeve is clean and scratch free as well as crank has no play. Drained oil and no signs of metal.... Now to my question, i assume i jusy buy a replacement piston that vitos sells or so any of you guys have suggestions on what piston to buy as far as a brand and what size i would need for my vitoz 240bb kit i have on now. Please with all regards i would love any feedback. Will post pictures here shortly. Thank you

 

[MURPH]

I doubt the sleeve is clean and scratch free with the piston looking like that.....get it bored and honed for the next size up which if its stock bore on the vitos the next size vito piston is 72.50 but u can get a wossner 72.25 piston and get 4 bores out of that cylinder

 

[Jgmblaster03]

Like no joke the sleeve looks brand new there is not one scratch what so ever..Stock bore? I assume you mean the 240bb kit i have on now? So then i would just buy a new piston?....i was just hoping to replace the piston.

 

[jbuckster07]

Like no joke the sleeve looks brand new there is not one scratch what so ever..Stock bore? I assume you mean the 240bb kit i have on now? So then i would just buy a new piston?....i was just hoping to replace the piston.

With damage like that, its soooooo hard to believe that the walls are not damaged. that thing took a beating dude!

Now we here on BF have seen this at least a dozen times in the last year:

motor is blown up, owner just replaces the piston, to the same size, comes back on and tells us it ran great! For about 2 hours until the piston skirt exploded on the exhaust port due to the piston not being FIT TO THE CYLINDER PROPERLY. Now the memebr not only has to pay for a SECOND PISTON, but a new bore, possibly a new crank, bearings, will now have to split the cases to PROPERLY clean out the bottom end from all of the piston skirt that was left behind. So now your $200 rebuild could cost you upwards of $500 becuase you want to save on a $65 rebore....

 

[Jgmblaster03]

I like the sound of that. Id rather not dump a ton of cash into this. So if i get it bored and honed again. Do i go bigger than what it has now?

 

[jbuckster07]

yes one size bigger, depenging on if the cylinder isnt too out of round, and take it to a reputable machine shop! Thats the most important thing! Most of us have had bad times with machine shops around here and send our cylinders out to a guy in CT names Ken OConnor Racing. Give him a call, I just shipped my cylinder and head to him this past week. Cost me like $15

BB Piston sizes are 72mm, 72.25mm, 72.50mm and 73mm. If yours is stock then its going to be 72mm.

 

[Blaster crazy]

Yep I would send it to ken and get ur piston from him too he will match it right up

 

[Jgmblaster03]

Thanks guys sounds great to me. Ill give them a call. Im from maryland. Not many machine shops around here that i kno do this kind of work

 

[nick20555]

Its real cheap to send just the cylinder to Ken to get it bored and matched to the next size piston. He will order a piston, measure it, and bore your cylinder to exactly the size you need for that new piston.

 

[Jgmblaster03]

Called ken today and was a really nice guy. Answered all my questions. Will be sending out my cylinder to get bored and honed and new piston. Will put pictures up when i recieve it and put back on my bike.

 

[Jgmblaster03]

Hoping this is all the work i need. Doubl2 checked everything today and crank case and crank are just fine. Case is clean and no play in crank what so ever.

 

[Jgmblaster03]

Another issue i wanted to point out was that when i first started my bike up before this problem i found out it got hot quick. Contemplating wether i should go back to stock or a slight bit over bore and sell the bbk or get the bbk fixed by ken oconnor but i dont want to run into the overheating issue.

 

[MURPH]

What carb and jet sizes are you using? ...my vitos 240 cylinder is bout 300 degrees at operating temperature

 

[nick20555]

What carb and jet sizes are you using? ...my vitos 240 cylinder is bout 300 degrees at operating temperature

300 degrees where? at the head or cylinder? just curious, I don't think i've ever done a completely warmed up heat test on mine. Just used the gun to see when the head got to 200 for my head cycles.

 

[nick20555]

Another issue i wanted to point out was that when i first started my bike up before this problem i found out it got hot quick. Contemplating wether i should go back to stock or a slight bit over bore and sell the bbk or get the bbk fixed by ken oconnor but i dont want to run into the overheating issue.

I got my BB cylinder bored to the next size (72.5) by ken and I don't have overheating issues. I do a good bit of woods riding never getting out of 3rd gear and spending a good chunk of time in 2nd gear too. I also got the +3 crank in it so its a heck of powerhouse.

 

[Jgmblaster03]

What carb and jet sizes are you using? ...my vitos 240 cylinder is bout 300 degrees at operating temperature

Honestly i could not tell you jetsize but i know i have a 34 kehin carb

 

[MURPH]

300 degrees where? at the head or cylinder? just curious, I don't think i've ever done a completely warmed up heat test on mine. Just used the gun to see when the head got to 200 for my head cycles.

on the cylinder

 

[Jgmblaster03]

Would this cause any issues with the new bored cylinder and piston?

 

[MURPH]

Looks like u got some detonation. ..u said u have a 34pj carb..tell us what jets, needle, and slide is in there....also what air temperature, other mods besides bbk and elavation do you ride at?​

 

[Jgmblaster03]

Looks like u got some detonation. ..u said u have a 34pj carb..tell us what jets, needle, and slide is in there....also what air temperature, other mods besides bbk and elavation do you ride at?​

34 kehin pj carb. Needle and jets that came with it..
V2 reed valve
Oil block off kit
Uni aluminum air box and filter
Boost bottle
Hellbound racing right side exhaust

As far as engine mods thats it