This is what my cylinder looks like from the exhaust port. Plus there's a Nick in the piston top. Hard to get a picture with my phone and auto focus.
marks on cylinder.
- Thread starter theresnoname4me
- Start date
And I can wiggle the piston with my fingers through the intake. Correct me if I'm wrong but the cylinder and piston should be a tight for correct?
That's a VERY, very mild "Clean up"- port job. That looks like two (2) points of a "four corner seizer" to me. What piston do you have in it a wiseco? They are know for that if they are not warmed up before use.
I would yank the head off to get a better look inside. Are you using pre-mix (my guess),or oil injection? If pre-mix, what ratio of oil to fuel are you running? I would pull the head (easy to do) and go from there.
ADVICE >>> Wash your Blaster well, especially under the fuel tank, before removing the head!
I would yank the head off to get a better look inside. Are you using pre-mix (my guess),or oil injection? If pre-mix, what ratio of oil to fuel are you running? I would pull the head (easy to do) and go from there.
ADVICE >>> Wash your Blaster well, especially under the fuel tank, before removing the head!
Not sure of piston. I think oem with stock bore. The previous owner said he just rebuilt it when I bought it. No bore just honed it. What's the torque for the head? Super easy coming off
Might as well pull the jug too, Get piston and bore measured for clearance and roundness, taper. Make sure ends of rings are at pins. If you pull piston , must use new pin clips.
Larry is right yank the cylinder and have the bore inspected for size, roundness and taper.
What one person call's a "rebuild" is different from what another person calls a "rebuild".
My guess is that it had a forged piston in that cylinder that got a "four corner seizure", so he slapped in a stock piston in the bore to sell the bike. Perhaps? Who knows? As for stock bore... how do you know its on 66mm? That's a stock cast piston you have there.
A piston is smaller at the top than at the bottom, or in other words tapered. This is partly for expansion of the top of the piston (the crown) when it gets to temperature. That "nick" at the top of the piston was caused my an object getting between the piston and a port opening.
Get that bore measured for sixe and lets go from there.
One last thing... when I picked up one of our Blasters years ago I knew that it had bad piston slap when I bought it. The bore was at 66.5mm and it had a stock size piston in it (66mm). I corrected the problem. So if someone ever tells you that an engine won't run like that .020 - .021 + thousands clearance in a piston to cylinder... oh yes it will, but it will have piston slap.
What one person call's a "rebuild" is different from what another person calls a "rebuild".
My guess is that it had a forged piston in that cylinder that got a "four corner seizure", so he slapped in a stock piston in the bore to sell the bike. Perhaps? Who knows? As for stock bore... how do you know its on 66mm? That's a stock cast piston you have there.
A piston is smaller at the top than at the bottom, or in other words tapered. This is partly for expansion of the top of the piston (the crown) when it gets to temperature. That "nick" at the top of the piston was caused my an object getting between the piston and a port opening.
Get that bore measured for sixe and lets go from there.
One last thing... when I picked up one of our Blasters years ago I knew that it had bad piston slap when I bought it. The bore was at 66.5mm and it had a stock size piston in it (66mm). I corrected the problem. So if someone ever tells you that an engine won't run like that .020 - .021 + thousands clearance in a piston to cylinder... oh yes it will, but it will have piston slap.
This picture shows me that the cylinder is also "out of round" because of the light and dark spots on the cylinder walls. I'm not talking about the rub marks. The cross hatch "hone marks" look like it was done by hand with a piece of sand paper. I bet when you pull that cylinder, there isn't any chamfering on the port either.
All completely fixable!
Yeah I was figuring I needed to pull the cylinder but I don't have the tools to check the bore. I did put the piston on bdc to check the rest of the cylinder. There is chamfering on the ports not great but it's there. The p.o. gave me the old piston which was broken on the top too. I'm pretty sure I'm going to buy parts and send them to get worked. Bore for the piston and most likely port job too. Depends on the budget though lol. Thanks guys
If your going to send it off to a machinist this is the man...
http://www.kenoconnorracing.com/
His prices are VERY reasonable and he will get you pointed in the right direction. Don't half ass your project.
I HIGHLY RECOMMEND that you get the porting done and also get the head re-chambered into a "Hemi", which doubles your power output RELIABLY, and Ken does very good job! If you want to send it to someone to get it done CORRECTLY and have it back in a very reasonable amount of time, talk to Ken.
I'm in Nevada and all the motorcycle shops up here in northern Nevada suck. That's why I do my own work. The reason I say this is because if you don't trust your local lazy motorcycle shop like me, then call Ken.
(860) 230 - 5003 kenoconnor07@aol.com
Everything you have there is 100% fixable!
http://www.kenoconnorracing.com/
His prices are VERY reasonable and he will get you pointed in the right direction. Don't half ass your project.
I HIGHLY RECOMMEND that you get the porting done and also get the head re-chambered into a "Hemi", which doubles your power output RELIABLY, and Ken does very good job! If you want to send it to someone to get it done CORRECTLY and have it back in a very reasonable amount of time, talk to Ken.
I'm in Nevada and all the motorcycle shops up here in northern Nevada suck. That's why I do my own work. The reason I say this is because if you don't trust your local lazy motorcycle shop like me, then call Ken.
(860) 230 - 5003 kenoconnor07@aol.com
Everything you have there is 100% fixable!
I've already been looking into him with all the talk about him on here. Just don't know if I should get a spare and build it now..
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