1mm oversized piston... Fit straight in?

[honda_power]

http://www.trademe.co.nz/Browse/Listing.aspx?id=260484724

Will this fit straight in? The Mikita i put in shat itself

[slofox]

Doubt it...

[bogan]

it may fit in, but dont think you'd ever get it out again :doh:

[slofox]

it may fit in, but dont think you'd ever get it out again :doh:

Not whole, anyway...

[honda_power]

thats what i was thinking... so id have to re sleeve or bore out and replate to fit in? cant really be bothered with that

[slofox]

thats what i was thinking... so id have to re sleeve or bore out and replate to fit in? cant really be bothered with that

Well, in the olden days a 1mm oversize would have been referred to as "40 thou oversize". That's 40 thousandths of an inch.

That's quite a big oversize...so you'll need to bore it out...

[bogan]

cant you just get a piston the right size? or did the mikati damage the bore?

[honda_power]

yeah right sized piston will be fine i was just looking at it because of the price.

[bogan]

didnt you learn your lesson after the mitikai? :shutup:

[honda_power]

Yeap...

The worst part is i now have to split it to get the bits of piston out

[bogan]

Yeap.........

fuckin aye, that doesnt look good, where did the bit end up? looks like it cuda done some damage :crazy:

[honda_power]

ended up as millions of little flakes that are now through the whole motor...

[jt119]

Yeap...

The worst part is i now have to split it to get the bits of piston out

my old cr did the same thing to the piston the bore had cracked between to ports and it picked up on it doing that to the piston hope yours hasnt

[bogan]

ended up as millions of little flakes that are now through the whole motor...

best of luck getting them all out, don't want em destroying any bearings. Had a bearing flog out in a cr i owned, one of the balls went up through the barrel and imbedded itself a good 3mm in the head, taking big gouges along the way.

[barty5]

gee wasnt so long ago booom was raving about these piston guess it back to yah get what yah pay for.

[barty5]

happy to $$ one up for you if you want wiseco, prox is out a stock

[cheese]

gee wasnt so long ago booom was raving about these piston guess it back to yah get what yah pay for.

He was raving about the price and wanting to know if anyone had used them. That's two bad stories about them, I'd not touch one!

[Reckless]

http://www.trademe.co.nz/Browse/Listing.aspx?id=260484724

Will this fit straight in? The Mikita i put in shat itself

Firstly whats it for the cr125?? Nicasil bore??
Anyway its simply not a question that can be answered on the net, your workshop manual will have the tolerance(ie correct difference between the bore and piston measurement) it will have to be measured, if its not now stuffed. Nicasil bores generally only have an A or B size nowhere near 1mm oversize. 2smokers are simple but you still have to get the basics right ie piston size and check ring end gap etc. You will have to take it to someone that can measure it up for you so you can get the correct piston.



gee wasnt so long ago booom was raving about these piston guess it back to yah get what yah pay for.

Given the above, it could have been completely the wrong size barty? May not be the pistons fault at all by the looks of things but we need a bit more info?

[honda_power]

it is an rm125

[CRF119]

That will teach you for buying cheap, i still would never use a wiseco piston eaither they are knowen to sieze.

Pro X or geniune is the only way to go from my experiance.

If you do need to bore it out send the psiton you want to use and get it electrosil plated to suit. Electrosil has less friction and is harder then any other coating. Had my CR125 done.

Get it ported at the same time :)

[scott411]

That will teach you for buying cheap, i still would never use a wiseco piston eaither they are knowen to sieze.

:)


forged pistons are only more likely to cold seize due to improper warm up,

im with you, i prefer genuine pistons over most,

what year RM125 is it, genuine suzuki kits are not to badly priced either

[barty5]

That will teach you for buying cheap, i still would never use a wiseco piston eaither they are knowen to sieze.

Pro X or geniune is the only way to go from my experiance.

If you do need to bore it out send the psiton you want to use and get it electrosil plated to suit. Electrosil has less friction and is harder then any other coating. Had my CR125 done.

Get it ported at the same time :)

Half the genuine stuff is Prox made anyway.

[Ride it till the red]

forged pistons are only more likely to cold seize due to improper warm up,

im with you, i prefer genuine pistons over most,

what year RM125 is it, genuine suzuki kits are not to badly priced either


What's a proper warm up in your books as to not cold seize a forged piston?

That's the reason I've never liked the idea of forged in a 2 stroke, but then again I've taken the risk and run a few of these Mitaka's now.... Not once had a problem :cool:

As far as warm up goes for me it's always been:

Choke out and give it a boot
Soon as it's running and revs are stable (5 secs or so maybe) put choke in
Give it a small blip or two every now and again whilst I gear up and get everything sorted
Jump on and take off, take it easy for the first minute or two ( generally on the flat near the trailer doing circles waiting for the others)
Wait another 2 or 3 minutes of actual riding before really raping it but after that it's fair game

Seems to work so far anyway :2thumbsup

[ManDownUnder]

thats what i was thinking... so id have to re sleeve or bore out and replate to fit in? cant really be bothered with that

yeah mate - the plunger needs to fit nicely in the hole... especially if it's staying in there a while and you don't want friction or leakage.

... what were we talking about again?

[vr4king]

Ive often wandered about the warm up procedure and i have been dabbling with the heat soak theory that i like to think i have made up myself

Start bike run for a short time say one minute then kill and suit up while the heat soaks through

Is this a bad idea???