125 engine transplants

[race_demon]

been 2 years since i last asked still same problem,
ive a kawasaki kdx 125 (b1) with a worn bore/cylinder and im either forced to get a new piston kit or i could get a new bore up kit (but will cost a fortune and is allot of work i reckon)

so im wondering would a kdx200/220 engine fit as a kx 125 engine is as rare as rocking horse p**
i doubt a kx250 would fit but it would be fun (possible?)
id rather keep my bike and buy a differant engine then save allot of money for a bigger bike (and insurance and tax etc)
please be kind im only young and advice/polite opinions is very much appreciated thank you.

[F5 Dave]

You won't find a KDX or KX engine in one piece that isn't already in a bike. They kill powervalves so any 2nd hand engine is suspect. Would it fit? Probably, but only after some mods & then the pipe & jetting are unlikely to be right. Starting to sound expensive. No one is going to sell a decent engine for less that $800 at any rate. Forget this option. It isn't a corolla.

OK So time to repair the kx. Is it just worn bore? ok so it's plated std, assume it hasn't been sleeved. Go to US chrome & ask for a price for a replate & wiseco piston kit. Even with postage it won't be that bad.

http://www.usnicom.com/price.asp

Have to post (trace) it marked as '2nd hand engine parts for repair'. Don't courier or will get tax going into US & back.

[race_demon]

ah gutted, im in england and for £25 gbp i can get a piston kit online (minus gaskets which are another £12) i know nothing about this sort of engines (im a vauxhall/open/car person) to me 2 strokes are 2 strokes and i aint gunna try and get it plated unless its dirt cheap (price of pistons and gaskets) i just wanna get it running,
ill inspect the bore if its scored and cheap enough to get fixed i will get it re plated and oversized if its fine WOO HOO!!!
ive had the bike 1 year and whe i bought it it had a new engine rebuild (complete) thatll teach me for running on mineral and not letting it warm up

ive had 2 votes to stick to bikes and 2 to get a car (asking the girls i know) ah dear maybe i should get a nova (corsa a) or a corsa b/ astra....i aint cut out for 2 strokes obviously

thanks dave

p.s the guy had spent £2000 on it says summin about its reliability and it came with a box of bits etc from the previous engine and it didnt have an oil pump cus apparently they kepp breaking and you only know theyve broken when the engine pops (nylon gear)

[F5 Dave]

Ahh, misread the bike(& location), I presumed kx125, we never got the kdx125 here as we have a 250 learner limit not 125. The kdx125 is road kitted hence the oil pump. Usually if you remove this & add oil it will be leaner petrol mixture than before as the oil is taking some space. It may be that it was rich enough std to cope with it if you ran ~40:1. Or it might be too lean & seize. An experienced mechanic will be able to tell if it was lubrication or mixture that caused the damage.

. . . and i aint gunna try and get it plated unless its dirt cheap (price of pistons and gaskets) i just wanna get it running,

Well it isn't going to be dirt cheap. Perhaps list it up on ebay & cut your losses if you aren't prepared to fix it. But nobody is gonna fix it for you. Try blowing up one of those turbo shitboxes & see what it costs.

[race_demon]

quote:-
p.s the guy had spent £2000 on it says summin about its reliability and it came with a box of bits etc from the previous engine and it didnt have an oil pump cus apparently they kepp breaking and you only know theyve broken when the engine pops (nylon gear)

ok maybe i should of been a bit more detailed (worried about making a long reply), the guy blanked off the oil pump and fitted a larger jet and said to mix it in the tank (and shake the f*ck out of it) he said 75ml/5 liters but me being young & nieve i thought "lets be safe and run more" so i ran it on allot more so it was pissing unburnt oil out the exhaust (like 32/1?(i just thought it was typical 2 strokes smoke which had condensed in the pipe)

please dont tell me the cylinders plated they arnt in cars lol what would the plating be and how much est??? cheers for sticking around

[F5 Dave]

well its hard to say what he did, but spooge pouring out the back is a rich petrol to air mixture. The unburnt extra gas just happens to have oil in it. So perhaps it was too large a mainjet he put in it. Google the std jetting spec & see how close it is. Keihin mainjets go up in sets like 160, 162, 165, 167, 170. (ie 2.5 but rounded)

He may have (should?) upped the pilot-jet, but experimenting with the mixture screw pos dictates the mixture in the pilot range (throttle closed).

75ml to 5 l is like 66:1. Not much oil at all. Would be better at 50:1 with a top notch oil, like Motul or Spectro or TTS or similar.

Follow the link in above post for est price of replate. No too bad. Older bikes have steel liners but they are archaic technology. Sometimes people put liners in plated barrels, but plating costs have come down. Try with a magnet. If it sticks it has a Steel liner.

I think you will find newer car engines will be plated, however they do keep old design engines going on for years so will take a while before they convert over.

[race_demon]

cheers bud your a star was about totake the head et off just asec ago but its too cold (so what im only human) and im worried ill find out summin along the lines of- oh summins jamming, oh this broke, oh....
so im taking it slow hence im online.

yeah it is an old bike so im hoping its gota steel liner (whats wrong with liners they do the job)
yeah new vehicles are often lined (better heat transfer, less friction [more power] etc)

the porsche cayenne has a silicon-aluminium block with no liners so light as a feather....unfortunately if a ring snags and scores the bore you need a new engine block...i love liners lol

been a while sinc ei ran it so cant remember what mix i ran but i know it was allot i got 10-15mpg (9l tank, 4.55l to a gallon you do the math)

cheers dave, star

[race_demon]

took the cylinder off (f*ckin kips) yeah the pistons worn bad considering the amount of oil i ran i dunno how the piston and bore touched enough to wear it (its bad!) so now ive gotta try and get the piston out (wierd circlips) and the kips is sticking bad and hav no idea how to take it out (will look) o the good side the cylinder is steel (appears to be) and isnt scored but has prob wor enough to need a rebore 0.5 up cheers