Need help with my Blaster

[TTRi23]

I just got a 1990 Blaster from a buddy. He doesnt know tons but awhile back he had some work done to it and he told me its now a 240 stroker. Now here is where it gets tricky for me. He messed up the cylinder a little bit. When I got the bike it came with a brand new 68MM piston which is 80 over from what I been told. So I am trying to figure out what route I should go in getting it repaired. I am not sure if its the stock cylinder sleeve just bored 80 over if its a diffrent sleeve?


If it is the stock sleeve can it be bored any more then 80 over? I have the cylinder at a machine shop and he told me after he checks it he could just bore it and I could get a bigger piston if they make it.

Only piston I have found is 90 over at 6.25 compared to the 80 over at 68.00

Sorry if it sounds confusing.


Thanks

 

[TopTechKid27]

if you can get a .90 over piston you can do it the only thing is the sleeve might get weak due to how thin it would be. if it were me i would just get it resleeved just so then your back to stock bore and have a ton of bores left, the machine shop should be able to do it. honestly its not a 240 either 240s use a 72mm piston i believe.

 

[TTRi23]

if you can get a .90 over piston you can do it the only thing is the sleeve might get weak due to how thin it would be. if it were me i would just get it resleeved just so then your back to stock bore and have a ton of bores left, the machine shop should be able to do it. honestly its not a 240 either 240s use a 72mm piston i believe.

Thats what the machine guy told me . But he said it would be cheaper to find a bigger piston if they made it.



Also I was thinking about buying a stock sleeve but my other conern is the ports from the stock sleeve going to match up on the cylinder? Because from what I been told the Cylinder has had some porting work done to it.

Thanks again for your quick reponse and I am sure i'll be asking many more questions.

Alex

 

[370]

ok dude lemme help ya out here.. first off... NEVER NEVER NEVER NEVER bore a cylinder without the piston... thats the hack ass hillbilly way of doing it.. piston first THEN BORE.. and any shop that says they'll bore without a piston.. take your cylinder adn find a COMPETENT SHOP.. ok... as for teh piston question.. a 68mm is an .080 over blaster piston for a stock sleeve.. 240's use a 72mm piston. and what you have is not a 240 stroker.. do you know how much stroke has been added? blaster cranks come in 3 size stroker. 3mm 4mm and 6mm. 3mm being the most common. it requires VERY LITTEL machine work.. the 4mm and 6mm require case trenching.. if it is a stroker it most likely has been ported.. for a stoker to work effectivly it need to have the port durations changed.. and all the port floors dropped. when you put the new sleeve in you'll need to have the sleeve port matched to the original porting in the barrel.

youir best bet is to weight your options.. on one hand you have to buy a sleeve and have it installed.. then pay to have it port matched..

on the other hand you could buy a used cylinder off ebay and pay to have it ported..
you'd be money ahead buying a used cyl IMO.. if you have any questions feel free to PM me.

 

[TTRi23]

ok dude lemme help ya out here.. first off... NEVER NEVER NEVER NEVER bore a cylinder without the piston... thats the hack ass hillbilly way of doing it.. piston first THEN BORE.. and any shop that says they'll bore without a piston.. take your cylinder adn find a COMPETENT SHOP.. ok... as for teh piston question.. a 68mm is an .080 over blaster piston for a stock sleeve.. 240's use a 72mm piston. and what you have is not a 240 stroker.. do you know how much stroke has been added? blaster cranks come in 3 size stroker. 3mm 4mm and 6mm. 3mm being the most common. it requires VERY LITTEL machine work.. the 4mm and 6mm require case trenching.. if it is a stroker it most likely has been ported.. for a stoker to work effectivly it need to have the port durations changed.. and all the port floors dropped. when you put the new sleeve in you'll need to have the sleeve port matched to the original porting in the barrel.

youir best bet is to weight your options.. on one hand you have to buy a sleeve and have it installed.. then pay to have it port matched..

on the other hand you could buy a used cylinder off ebay and pay to have it ported..
you'd be money ahead buying a used cyl IMO.. if you have any questions feel free to PM me.

I know about having the pistons first. Thats why I told the guy to let me see if I could get the piston. Thanks for the help and its a 4mm crank had port work done along with the head shaved for clearence and other work.?(got that info from my buddy).



So you think I should buy a used cylinder have it ported and just start with the stock bore and work my way up?

 

[370]

yeha thats the way i'd go with it i think.. the sleeve alone would cost more than a used cylinder on ebay.. i've seen blaster cyls go on ebay for $50 or less.. piston will be teh same price for either so thats a wash.. the sleeve install and port match would cost more than just porting the used cylinder off ebay..

 

[TTRi23]

yeha thats the way i'd go with it i think.. the sleeve alone would cost more than a used cylinder on ebay.. i've seen blaster cyls go on ebay for $50 or less.. piston will be teh same price for either so thats a wash.. the sleeve install and port match would cost more than just porting the used cylinder off ebay..

Yea thats what I was thinking. I just didnt know sense it has a diffrent crank it in if a stock cylinder/bore would work.


So i'll keep a eye out pick one up then just have it ported.

 

[joedirt5724]

3 reasons u dont over bore. #1 Cylinder wall get weak, #2 Pistons get harder to find the bigger you go, and #3 you will have cooling issues with anything .80 over bore.

 

[TTRi23]

3 reasons u dont over bore. #1 Cylinder wall get weak, #2 Pistons get harder to find the bigger you go, and #3 you will have cooling issues with anything .80 over bore.

It was going to cost me 180 forthe piston and the bore. So I talked my girlfriend into letting me just find a cylinder and get it ported. I am pretty sure between here and ebay I can get a used one easy enough.


Anyway thanks alot guys.

 

[Cmh156]

It was going to cost me 180 forthe piston and the bore. So I talked my girlfriend into letting me just find a cylinder and get it ported. I am pretty sure between here and ebay I can get a used one easy enough.


Anyway thanks alot guys.

My friend got one! Needs bored,ill have to check the size its at i think its at .20 or .40.

Pm 07eigerrider. Hes letting it go pretty cheap.

 

[TTRi23]

My friend got one! Needs bored,ill have to check the size its at i think its at .20 or .40.

Pm 07eigerrider. Hes letting it go pretty cheap.

Thanks man I just hit him up.

 

[Cmh156]

Thanks man I just hit him up.

No problem,he also got paypal too so its not shady or anything.

 

[TTRi23]

No problem,he also got paypal too so its not shady or anything.

Ive dealt with many people online so it shouldnt be a problemI:I



Just curious does any one know the years of the cylinder that will work.

I am pretty sure most years will.

 

[Cmh156]

Ive dealt with many people online so it shouldnt be a problemI:I



Just curious does any one know the years of the cylinder that will work.

I am pretty sure most years will.

All blasters are the same except.

1988 and 1989 they went from a 220 or 230 main jet.

1988-02 had cable brakes and a 4 wire stator.

03-06 had hydros and a 5 wire stator.