Blaster top end rebuild
- Thread starter Quadman1
- Start date
are you holding the thottle wide open and kicking it until the needle stops moving ?
as mentioned above, did the cylinder to piston clearence measurement suggest that only a hone/new rings were needed ?
or was the cylinder wear beyond spec and a bore/new + piston was needed ?
i see no mention of new piston or rings ?
as mentioned above, did the cylinder to piston clearence measurement suggest that only a hone/new rings were needed ?
or was the cylinder wear beyond spec and a bore/new + piston was needed ?
i see no mention of new piston or rings ?
time to pull it apart and measure this time................
http://www.blasterforum.com/engine-13/how-measure-your-cylinder-diy-25767/
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reason im asking is people buy a used atv, and assume its standard bore just by their own judgement or the previous owners promise, so they buy standard piston and rings and swear nothing could have been done wrong, an overbore to fix scratches is not a huge difference in size to the eye. the correct way to do it is get a general as close as you can size of the bore before any work, order the next size up piston and bring it to the machine shop doing the work, sure you can hone it, but if the bore was tapered or out of round would you be able to measure it at home? i know i can't and wont even try
You said the piston shattered. Did you get it all out of the bottom end? If the piston shattered chances are there was to much piston clearance to begin with.
You have to measure ring gap or piston to wall clearance. Cylinder could have been tapered or out of round. Did you measure with inside mics or calipers?
Calipers wont give you an accurate reading on something so minute.
The very top of the cylinder will always be a little bigger due to the piston only coming up to right below it, so the wear on the cylinder will be below that line (where you measured)
Chances are you need a bigger piston, dont half ass these type of jobs, they must be done correctly.
And ALWAYS leak test!
The very top of the cylinder will always be a little bigger due to the piston only coming up to right below it, so the wear on the cylinder will be below that line (where you measured)
Chances are you need a bigger piston, dont half ass these type of jobs, they must be done correctly.
And ALWAYS leak test!
Please don't take this the wrong way. Alot of people end up like this. Thinking a piston and rings will solve the problem, but its much greater. Take that top end to a shop and get it measured, bored/honed, clean out all the piston debris out of the crank, then enjoy some peace of mind riding.
This is the best advise I can give you. Good Luyck to you.
Fred
This is the best advise I can give you. Good Luyck to you.
Fred
You say you cleaned out the bottom end.
I trust that you mean that you split the cases and replaced/cleaned the bearings and fitted new seals.
If you did not split cases be prepared for a costly rebuild.
I trust that you mean that you split the cases and replaced/cleaned the bearings and fitted new seals.
If you did not split cases be prepared for a costly rebuild.
NO,
i think it's a better idea to have your standard bore cylinder bored and fitted with a new over sized piston by a reputable shop
Agreed. No reason to waste money on a used cylinder when u have a perfectly useable cylinder already. Calipers give you an idea but are no where near accurate for measuring bores.
