DeanG Posted January 22, 2011 Share Posted January 22, 2011 Hey, topend blew on my bike so I stripped it down today to find a scored up piston - Shop quoted me £110 for new piston, rings, clips etc but I've found them cheaper online... Is the standard (non oversize) piston 57.00mm? Cheers Link to comment Share on other sites More sharing options...
Moderator mervin Posted January 22, 2011 Moderator Share Posted January 22, 2011 Ok 1. what is the state of the barrel cos if the piston is scored the barrel is possibly too,in which case you willl need a rebore and piston, 2. pistons, Is the shop quoting for gen yam?? are you looking at cheap chinese pistons, at the very least buy a mitaka or prox pison kit anything cheaper will not last 3. why did it do this in the first place? have you fitted an aftermaket exhaust and not altered the jetting too suit??, are you running it without the air filter or fitted a diferent one ??? did it run out of oil??? all these things need addressing before you start using it again and it seizes again in short order Link to comment Share on other sites More sharing options...
DeanG Posted January 22, 2011 Author Share Posted January 22, 2011 Everything is stock, nothing has been altered and the oil was changed 3 weeks earlier to the correct type it said in the manual - Think it was just its time to go Yeah it is a chinease one, but really its only temporary as I don't have the funds at the minute (debt and what not) - So maybe a month or 2 with the chinease one then I was going to rebuild it with a genuine kit. Just need to know the size before I order - I think its 57mm Thanks for the reply Link to comment Share on other sites More sharing options...
root Posted January 22, 2011 Share Posted January 22, 2011 Piston diameter XT 125R/X 2005/09 ...53.977mm - 53.996 mm according to haynes . Where do you get 57 mm from , the old XT ? You should take notice of mervin, or it will probably end up costing you a lot more , or worse . Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 22, 2011 Moderator Share Posted January 22, 2011 Ok 1. what is the state of the barrel cos if the piston is scored the barrel is possibly too,in which case you willl need a rebore and piston, 2. pistons, Is the shop quoting for gen yam?? are you looking at cheap chinese pistons, at the very least buy a mitaka or prox pison kit anything cheaper will not last 3. why did it do this in the first place? have you fitted an aftermaket exhaust and not altered the jetting too suit??, are you running it without the air filter or fitted a diferent one ??? did it run out of oil??? all these things need addressing before you start using it again and it seizes again in short order Hey Merv I know prox and mitaka do quality pistons (i would always use them or genuine if possible) but do they do them for 4 strokes too? as in this bike Link to comment Share on other sites More sharing options...
DeanG Posted January 22, 2011 Author Share Posted January 22, 2011 Must be the old one I got the sizes from - Looks like I'll have to go with the OEM one from the shop - Extortion but the only one I can find.. He wanted £34 for the piston £38 for the rings £1 for the clips and a few other bits - Came to £111 inc vat Link to comment Share on other sites More sharing options...
2 Wheels Posted January 22, 2011 Share Posted January 22, 2011 Must be the old one I got the sizes from - Looks like I'll have to go with the OEM one from the shop - Extortion but the only one I can find.. He wanted £34 for the piston £38 for the rings £1 for the clips and a few other bits - Came to £111 inc vat Thats not bad for OEM parts,,,,,,,,,,and at least it will last. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 22, 2011 Moderator Share Posted January 22, 2011 What about the bore Dean? Link to comment Share on other sites More sharing options...
DeanG Posted January 22, 2011 Author Share Posted January 22, 2011 What about the bore Dean? No scoring visible, feels smooth - The piston scoring isn't that bad at all either - Caught it at an early stage I want to check the stem seals too, but I haven't a clue how - No tutorials anywhere... Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 22, 2011 Moderator Share Posted January 22, 2011 you know Dean...this is really unusual for a 4 stroker! hear a lot about 2 strokes because they are very sensitive to carburation. is the oil level ok, does the bike have an oil pressure light etc. wouldnt want it to happen again, how about some pics of the damage? Mervin made some good points earlier and 4 strokers are normally pretty bombproof. Link to comment Share on other sites More sharing options...
DeanG Posted January 23, 2011 Author Share Posted January 23, 2011 you know Dean...this is really unusual for a 4 stroker! hear a lot about 2 strokes because they are very sensitive to carburation. is the oil level ok, does the bike have an oil pressure light etc. wouldnt want it to happen again, how about some pics of the damage? Mervin made some good points earlier and 4 strokers are normally pretty bombproof. Oil levels were fine I checked them over a lot (Unless the previous owner neglected it for some time before sale - But when I got the bike it had enough oil still but I changed it anyway as a precaution) Bike just started smoking a lot once warmed up (Wouldn't smoke at idle, just on revs), sometimes it was white - then sometimes it was blue :| So I decided I'd strip it down and take a look - Found a few scratches on the exhaust side of the piston (which I am led to believe means a lean condition at some point) - But the funny thing is the scores are like 3 underneath each other going horizontally :S Around the sides of the piston there was a lot of evidence of burning of some sort - Which I thought wasn't normal. I was told the bike was reliable by a load of people - I mean its a 125 and a 4 stroke what more can you ask for lol - Bike never really did have much power at all but whether thats the fact that the bike never had power to start with is another thing... My 110cc pitbike pulled better anyway Thanks for all the feedback I'll get a picture of the scores tomorrow! Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 23, 2011 Moderator Share Posted January 23, 2011 Oil levels were fine I checked them over a lot (Unless the previous owner neglected it for some time before sale - But when I got the bike it had enough oil still) Bike just started smoking a lot once warmed up (Wouldn't smoke at idle, just on revs), sometimes it was white - then sometimes it was blue :| So I decided I'd strip it down and take a look - Found a few scratches on the exhaust side of the piston (which I am led to believe means a lean condition at some point) - But the funny thing is the scores are like 3 underneath each other going horizontally :S Around the sides of the piston there was a lot of evidence of burning of some sort - Which I thought wasn't normal. I was told the bike was reliable by a load of people - I mean its a 125 and a 4 stroke what more can you ask for lol - Bike never really did have much power at all but whether thats the fact that the bike never had power to start with is another thing... My 110cc pitbike pulled better anyway Thanks for all the feedback I'll get a picture of the scores tomorrow! is it a water cooled bike? Link to comment Share on other sites More sharing options...
DeanG Posted January 23, 2011 Author Share Posted January 23, 2011 is it a water cooled bike? Air cooled Link to comment Share on other sites More sharing options...
Moderator mervin Posted January 23, 2011 Moderator Share Posted January 23, 2011 Hey Merv I know prox and mitaka do quality pistons (i would always use them or genuine if possible) but do they do them for 4 strokes too? as in this bike paul i started reading this and it has all the symptoms of a 2 stroke seize, then read XT, not sure about who makes the pistons but there are cheapo chinese offerings for XT,s around, started searching ebay and came across this now that has a 4 stroke barrel and a mitaka piston the only one i have found though, the guys quote of 57 mm seemed possible but everywhere i looked the dates where wrong so i could not reply too that Anyhow lets see what happens valve seals are generally at the top of the valve stem under the spring while you have it torn down it would pay to replace these as they can make it smoke and you should have em in a gasket set Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 23, 2011 Moderator Share Posted January 23, 2011 Air cooled Dont be sad Dean, air cooled is good Link to comment Share on other sites More sharing options...
DeanG Posted January 23, 2011 Author Share Posted January 23, 2011 Here's the pictures - Sorry I had to use a phone but I tried to make the marks as clear as I could - Doesn't help that I've cleaned the piston up a bit! http://up2go.us/static/img/IMG00859-20110123-1855.jpg http://up2go.us/static/img/IMG00860-20110123-1855.jpg http://up2go.us/static/img/IMG00861-20110123-1855.jpg Edit: Changed them to links they are far to big :| Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 23, 2011 Moderator Share Posted January 23, 2011 Pics are crap Dean get a new camera but only looks very minor marking and what puzzles me is they are not vertical scores? Does it really need a new piston...why not just rings? Like I say pics are crap so I might be missing something here Link to comment Share on other sites More sharing options...
DeanG Posted January 23, 2011 Author Share Posted January 23, 2011 Pics are crap Dean get a new camera but only looks very minor marking and what puzzles me is they are not vertical scores? Does it really need a new piston...why not just rings? Like I say pics are crap so I might be missing something here Yeah pics do suck really bad sorry - Had to use a phone I can't find any batteries for my camera! Don't see much point getting new rings only, I'm not sure what it needs out of the 2 but I might as well replace the 6 year old piston if I'm doing the rings too! I can't even see any ring damage tbh I'm not sure at all... I was really confused by the scores, I can't think of an explanation to why they are horizontal, and they are all on the exhaust side with a few more faint scratches Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 23, 2011 Moderator Share Posted January 23, 2011 Yeah pics do suck really bad sorry - Had to use a phone I can't find any batteries for my camera! ........ LOL batteries come from SHOPS and the like Link to comment Share on other sites More sharing options...
DeanG Posted January 23, 2011 Author Share Posted January 23, 2011 LOL batteries come from SHOPS and the like Shops are for people who aren't in debt Link to comment Share on other sites More sharing options...
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