I think I broked it

[quallman1234]

Anyone notice the 50's passing me in a straight line, this could be why.

Must of being me, re-using the circlips, taking the piston in and out a couple of times.

[Ivan]

Haha
Looks like it needs sorting out with a just dunne it port barrel lol
thats what my mate used tosay about that engine when i owned it.

And bugger man at least the piston was fairly cheap

[Buckets4Me]

another piston sacrifced to the god of speed

[speedpro]

Admit it man. You farked up and didn't assemble it properly. I've wrecked some engines good and proper and apart from the last one the clips have always stayed in the grooves. The last one the groves were broken as well!

[quallman1234]

Mmm, i could swear they were in good and proper, i even got dad to double check.

Aww well!
The barrell is in good condition, at least!

[Buckets4Me]

come one speedpro he used old clips
now tell me why you use new ones every time

[quallman1234]

come one speedpro he used old clips
now tell me why you use new ones every time

It was a brand new piston kit.

[Skunk]

It was a brand new piston kit.

I thought you reshaped some tired old one that was the wrong size...

[quallman1234]

I thought you reshaped some tired old one that was the wrong size...

Nope i used the one's out of the packet, the circlips glen gave me were far too big.

Its probabaly because i put the piston in and out 2 -3 times, because it wasn't fitting properly, and had to file a little amount of the bottom, probabaly fatiqued them.

Lesson learned

[Skunk]

It's probabaly because I put the piston in and out 2 -3 times, because it wasn't fitting properly, and had to file a little amount of the bottom, probably fatigued them.

Ahh. There's your first warning that something™ is wrong.

[bungbung]

it needs sorting out with a just dunne it port barrel

It's an easy fix though

[quallman1234]

Ahh. There's your first warning that something™ is wrong.

I assumed it was a casting error.We measured up the other piston and compared everything too the other piston, everything seemed to measure up correctly, we discovered that the bottom of the piston was a slightly different shape, took off maybe 2mm around the bottom of the piston, compared it to other, seemed ok, cleared the crank. It had the same amount of clearance, as the other piston.

Remember my big thread about the piston not fitting properly?

[koba]

All I need to say is this...

[speedpro]

All I need to say is this...

Friends don't reccommend 4-strokes to friends.

[speedpro]

That's why I buy circlips in packets of 10. If I pull a circlip out of a piston I always twist it up and wreck it so I cannot be tempted to try and use it again. They're cheap. Sounds like you need to be checking dimensions pretty carefully on the next piston and also looking at squish clearance etc. If your new piston had a skirt that was lower than the original piston then typically that piston will also have a lower deck height. Your compression may have been 5:1 with a 3mm squish clearance. Not exactly a big horsepower setup. (edit) just re-read thread and you did measure. Funny then that it should interfere with crankshaft.