spider.20 Posted March 27, 2006 Report Share Posted March 27, 2006 i'v just melted my motorbike! an i'm gutted. i some how managed to makt thermite out of the spark plug and burn a hole down through the piston head got it in bits now trying to clean out all the bits of melted piston from the rest of the engine. i'll post picks wen i get home from work tomoro. i'd do it earlyer but the children need there hair products but it's ok i can fix her. i got new bits from wemoto.com an managed to resist getting an oversized piston an a rebore. but i still need a new cylinder coz mine is prity badly scored so back on ebay wen the pay comes in any of you bikers had this happen before? or am i special like my mum says spider ps didn't manage to resist getting a new front sprocket with 2 extra teeth tho! Quote Link to comment Share on other sites More sharing options...
neilbe2 Posted March 27, 2006 Report Share Posted March 27, 2006 any of you bikers had this happen before? or am i special like my mum says yes your definatley special! Quote Link to comment Share on other sites More sharing options...
spider.20 Posted March 27, 2006 Author Report Share Posted March 27, 2006 i knew it! got some impressive piks of a my melted plug to put up to moro. how hot do spark plugs get before they melt? spider Quote Link to comment Share on other sites More sharing options...
Hunter Posted March 28, 2006 Report Share Posted March 28, 2006 Thats not thermite You have bad engine timing which caused nocking and pinging (combustion in the cylinder when the piston is not at the correct height). Im sure that will cost you to get sorted Again, its timing problems that will cause the spark plug(s) to melt or become damaged. here, maybe this will help. I use this quite a lot http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html Quote Link to comment Share on other sites More sharing options...
old rooster Posted March 28, 2006 Report Share Posted March 28, 2006 My money would be on it running too lean. Quote Link to comment Share on other sites More sharing options...
Bazooka Joe Posted March 28, 2006 Report Share Posted March 28, 2006 Happened to me once on a 200 Yam I'd bought, someone had put long reach sparkplugs in, instead of short reach, hole straight through the pistons. Bazooka Joe Quote Link to comment Share on other sites More sharing options...
Axe Posted March 28, 2006 Report Share Posted March 28, 2006 My money would be on it running too lean. Could even be the wrong grade of plug running too hot. -or- Being thrashed downhill with the wind behind it. What is it anyway, a scooter? Dont know many bikers on a scooter. Quote Link to comment Share on other sites More sharing options...
Fenlander Posted March 28, 2006 Report Share Posted March 28, 2006 I'd bet its a Moped ! If you are going up two teeth on the front sprocket,you are looking for more top speed, I used to do this many many years ago on my TS50 :thumbs: Mopeds and Fat Birds ! both good fun, but ya would'nt want ya mates to see you with one!!! :blink: Quote Link to comment Share on other sites More sharing options...
Pedro Posted March 28, 2006 Report Share Posted March 28, 2006 I'd bet its a Moped ! If you are going up two teeth on the front sprocket,you are looking for more top speed, I used to do this many many years ago on my TS50 Mopeds and Fat Birds ! both good fun, but ya would'nt want ya mates to see you with one!!! :( Oh yes, as well as taking the baffles out, putting Castrol R in, shaving a bit off the inlet ports and putting different reeds in. Happy days :thumbs: :blink: Quote Link to comment Share on other sites More sharing options...
lurcherboy Posted March 28, 2006 Report Share Posted March 28, 2006 Many reasons mate. Lean mix, timing, air leak etc. Suggest you source the problem before you think about the re-build or you may well be back at square one :thumbs: LB Quote Link to comment Share on other sites More sharing options...
spider.20 Posted April 4, 2006 Author Report Share Posted April 4, 2006 frankly i'm insulted! :< scooter? moped? these are toys for children! this is/was my bike. she's a yamaha RXS100 and has skinned a few scooters in her time. i'v got new bits for her but getting the engine casings off is trikyer than it looks. some one has chewed all the bolt heads. and finding a new barrel is proving difficult so i may have to go for a .25mm rebore. but i'd like to keep the engine standard if i can as lots off people modded an RXS100 beffore only to have it run at 120mph for three days then blow up! :o oh an as for running her too lean that may well be the case so i'm going to check the oil feed for blocages and the gasgets too coz theres a good drip coming off the bottom sincce she melted. piks of the damage up soon :( spider ps anyone got a TZR there wanting shot off? :( Quote Link to comment Share on other sites More sharing options...
tenbears10 Posted April 4, 2006 Report Share Posted April 4, 2006 Mopeds and Fat Birds ! both good fun, but ya would'nt want ya mates to see you with one!!! :( :( :blink: :o :( :( **** Quote Link to comment Share on other sites More sharing options...
Yorkshire Pudding Posted April 4, 2006 Report Share Posted April 4, 2006 lots off people modded an RXS100 beffore only to have it run at 120mph for three days then blow up! :o I'll wait to flamed but 120mph :( How the hell do you get one to do that speed :( Take it sky diving ? all the best yis yp :( Quote Link to comment Share on other sites More sharing options...
the last engineer Posted April 4, 2006 Report Share Posted April 4, 2006 drop it off beachyhead :o :( :( ,,,,,,,,, in neutral of cource dont wanna cause drag :( :( :blink: Martin Quote Link to comment Share on other sites More sharing options...
kirky640 Posted April 4, 2006 Report Share Posted April 4, 2006 i had a suzuki gp 100 when i was 17 years young and in a year i put 6 pistons and a new barrel on her i thrashed the living day lights out of it lol oh well i was young an daft great fun tho cheers kirky Quote Link to comment Share on other sites More sharing options...
Axe Posted April 4, 2006 Report Share Posted April 4, 2006 Nought wrong with them mate I bought an RS-100 back in my teen days. It had been well and truly improved. Customised TZ-250 crank fitted fully ported etc etc etc. I was clocked at 125mph. The power band really put a smile on your face until it ran out only to find a second one. :o Unfortunately, standard fuel wasnt right for it without additives and I went through more plugs than I care to mention before finally going through the piston. The bike in question is responsible for the large scars i have on my left arm. Lesson learnt, it may go fast, but it never handles at that speed, even with the sticky 130 on the back. :( If you want to go faster, get a bike designed for it. Quote Link to comment Share on other sites More sharing options...
poppythedog Posted April 5, 2006 Report Share Posted April 5, 2006 Nought wrong with them mate I bought an RS-100 back in my teen days. It had been well and truly improved. Customised TZ-250 crank fitted fully ported etc etc etc. I was clocked at 125mph. The power band really put a smile on your face until it ran out only to find a second one. Unfortunately, standard fuel wasnt right for it without additives and I went through more plugs than I care to mention before finally going through the piston. The bike in question is responsible for the large scars i have on my left arm. Lesson learnt, it may go fast, but it never handles at that speed, even with the sticky 130 on the back. If you want to go faster, get a bike designed for it. Customised TZ 250 crank?? you mean cut in half??? damn clever trick getting a twin cyl crank into a single cyl engine!!! Quote Link to comment Share on other sites More sharing options...
BERETTA687 Posted April 5, 2006 Report Share Posted April 5, 2006 i knew it! got some impressive piks of a my melted plug to put up to moro. how hot do spark plugs get before they melt? spider hi, if you are still stuck there could be a number odf reasons- -wrong spark plug(resistor isnt rite size for cc) -running very lean (fuel mix) -timing dunno but they could be the problem, never heard of a piston melting , would have to be really hot and even then you would have thought with the metal expanding it would have seized first. Quote Link to comment Share on other sites More sharing options...
spider.20 Posted April 5, 2006 Author Report Share Posted April 5, 2006 i'v never had any thing over 70mph out of my RXS but if you tweek them enough they will shift. just the usual: port the cyclinder, tweek the carb, add racing reeds, fit an expansion chamber , and one mighty rebore. not happening to mine tho sept mybe for the rebore as finding a new cyclider is triky. heres some piks of the damage you can't realy see it but that's some good scoring that's catching the light. you'd think i was trying! but on a lighter note i am in negotiations to get a nice TZR 125 no need to mod it or anything. spider Quote Link to comment Share on other sites More sharing options...
spider.20 Posted April 24, 2006 Author Report Share Posted April 24, 2006 UPDATE: she's just about back on the road! got a bunch of bits from ebay an soon as i get the set of crank casings i can swap the bits out of my old engine into the new one! after some minor attacking with an angle grinder . managed to find a new cylindetr too(0.25 oversized ) i still want a new bike once i get the baby yamaha back on the road but i'll have to test her out a bit. anyone got any experience with the kymco zing? cheers spider Quote Link to comment Share on other sites More sharing options...
Hunter Posted April 24, 2006 Report Share Posted April 24, 2006 (edited) No idea.. But from my experiance I would say you had the wrong spark plug. Either too hot, or too long. Thats what caused the ping (explosions inside the the cylinder) and a hole to burn through the piston. good to hear its back on the road! enjoy a summer of riding.. Pitty im selling my bike well.. trying too.. Edited April 24, 2006 by Hunter Quote Link to comment Share on other sites More sharing options...
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