How do you get a freshly seized piston from the jug. I can not get the piston to become unjammed. I must of kicked started this at least 100 times after a rebuild but when I tried a small amout of starting fluid, the engine rand for a second and jammed hard. After about 3 hours, I gave up and will have to cut the connecting rod. What might of caused this?

 

I wouldnt cut the rod. If you do the piston will still be stuck anyway. If all else fails and it will not slide out I'd smash the pistonwith a punch and take it out in pieces before I cut the rod. I would put rags or a big towel beetween the jug and crankcase to keep the pieces out. Ive not yet come across one that I couldnt knock loose with a piece of wood and hammer though.

 

Yup, its too late. I had a wooden handle and place it in the cyclinder and struck it about 2 dozen times with a sledge hammer and has no luck, I cut the rod and removed the jug. I must of kick started the engine over 100 times with no issues besides low compression. I took the top half apart took the rings out and reinstalled everything with no issues but again only 90 PSI. The ring appeared to flip once the piston went below the exhaust port after I used starting fluid( very small amount). The head was just bored to match the piston and even though I hae rebuilt several car engines, I thought this should of been easy, but oh well. Can anyone comment on how it will be to replace the crank?

Chuck

 

Chuck I am trying to follow you on when you say jug. Are you refering to the head? Well to replace the crank you are going to need to take the whole motor apart. A little advice, when you seperate the two cases you will need to take the clutch basket and inner hub off. To do this take the clutch out, then get a cleen grease rag and hold the inner hub. Then with a impact wrench lossen the nut inside the hub(before doing that make shure the lock ring flange is bent down). once you got the basket off take off all the remaining gears. The reason you take off the clutch is that when putting the motor back together you are supose to put the transmission on the side were the flywheel goes the put the other case on top off that. The best thing to do is to go and get a service manual. If you have any questions on how to install the crank just ask, I have replaced four cranks on a couple different blaster most of them are vitos stuffer cranks.

 

people usually mean the cylinder when they say "jug"

 

Hey Blaster 240,

thanks for the reply. Is there anything special I need to do to when seperating the case. I have played with auto engines but not a small 200CC blaster engine. Is the crank balanced? can it be seperated and have the rod replace or should I just pick up a used / new crank assy.

 

Hello,

How Big do you want to bore without going to thin . I know chevy 350 engines would not recommend anything over .60 due to heating issues. Would .60 over be ok and would any other adjustments to the carb be needed. I am not looking for any extra power, just a reliable quad.

Thanks
Chuck

 

My friends have borerd them up to .080 over and had no more trouble than they had before, I think thats the biggest OEM piston they make. I wouldnt bore it any more than needed to clean up the cylinder though, you will not gain enough power to notice by boring it farther than needed. I would have smashed the piston with a steel punch before I cut the rod, that was a really drastic thing to do over a stuck piston. [img]i/expressions/face-icon-small-tongue.gif[/img]

 

EI have found this note in the instructions. if my machinist didn't follow these directions, I assume the outcome would be a seized piston. I had a large wooden handle on top of the piston smashing it with a large sledge hammer and the thing didn't budge. After that much stress, I decided It couldn't hurt to rebuild the bottom end. So speaking of the bottom end, Does any one have any comments, especially when it comes to replacing the connecting rod / seperating the crank in half? Can it be done right?
Chuck


xhaust Power Valves (2-cycle engines)
When boring cylinders with exhaust power valves, the exhaust power valve must be inspected
to ensure it does not extend into the cylinder. The exhaust power valve must have
approximately .015" clearance from the cylinder bore. Without proper clearance, the
exhaust power valve could contact the piston and engine damage could occur. If
machining the exhaust power valve is necessary, remove metal only in the area that extends

 

Pretty sure a Blaster doesnt have a "xhaust power valve". My freinds Blasters didnt or at least didnt have what was called a power valve on my Suzukis.