forest of dean redneck 11,191 Posted February 25 Report Share Posted February 25 Just now, poxon said: The dt an tz are very similar engines think it was just the cylinder head that was different and the gearing. Bet that dt flew! Last dtr I had was a k reg it’d do the clock 80mph my mate had a little tzr 125 that little thing was mental he tuned it himself that would go off the clock I’m sure they had 110 mph Yeah I’m sure it had the tiny tzr wheels on so was rapid 1 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 Little kx is whooped 🥲down on compression to much wringing its neck! I was going to wait a while an finish collecting all the bits to do a race themed build but looks like it’ll be getting fully stripped over the next week 3 Quote Link to post Share on other sites
tillylamp 1,809 Posted March 30 Report Share Posted March 30 42 minutes ago, poxon said: Little kx is whooped 🥲down on compression to much wringing its neck! I was going to wait a while an finish collecting all the bits to do a race themed build but looks like it’ll be getting fully stripped over the next week wow that is low, did that bike start/run any good with 50psi....if it did, that gauge must be up the creek...a good engine would be around the 150psi mark, i think.... 1 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 6 minutes ago, tillylamp said: wow that is low, did that bike start/run any good with 50psi....if it did, that gauge must be up the creek...a good engine would be around the 150psi mark, i think.... Amazingly it still runs but lumpy as hell the revs hang up like it had a air leak ticks over like crap then cuts out I first thought crank seal was bad and drawing in air I’m guessing the only reason it runs with 50psi is because it ain’t got a conventional carburettor im using a lectron meter rod jetless carb on it so it’s self adjusting so would just dump the amount of fuel an air to run it. The gauge is a fresh un only used twice when I first put the bike together I’m sure it had about 160psi might have had a little more 2 Quote Link to post Share on other sites
tillylamp 1,809 Posted March 30 Report Share Posted March 30 8 minutes ago, poxon said: Amazingly it still runs but lumpy as hell the revs hang up like it had a air leak ticks over like crap then cuts out I first thought crank seal was bad and drawing in air I’m guessing the only reason it runs with 50psi is because it ain’t got a conventional carburettor im using a lectron meter rod jetless carb on it so it’s self adjusting so would just dump the amount of fuel an air to run it. The gauge is a fresh un only used twice when I first put the bike together I’m sure it had about 160psi might have had a little more yep...time for a tear down, when your done, how long between rebuilds... 1 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 2 minutes ago, tillylamp said: yep...time for a tear down, when your done, how long between rebuilds... Top ends on motor cross bikes vary some say after every race meeting they like to put a fresh top end on most people say 20hours some say you should get 40hrs I’ve a hour meter on mine I’m at 21.8hrs I think these little 125 should be done pretty regularly as they only have 1x piston ring and are a highly strung engine I think mines got a normal cast piston in it but think I’ll up grade to a forged race piston I’ve just looked at a kit it’s £150 for a top end kit 1 Quote Link to post Share on other sites
mC HULL 10,440 Posted March 30 Report Share Posted March 30 37 minutes ago, poxon said: Amazingly it still runs but lumpy as hell the revs hang up like it had a air leak ticks over like crap then cuts out I first thought crank seal was bad and drawing in air I’m guessing the only reason it runs with 50psi is because it ain’t got a conventional carburettor im using a lectron meter rod jetless carb on it so it’s self adjusting so would just dump the amount of fuel an air to run it. The gauge is a fresh un only used twice when I first put the bike together I’m sure it had about 160psi might have had a little more the flywheel side seal is easy to spray easy start or carb cleaner etc around it see if it changes the note mate i always stick with cast pistons were i can 1 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 1 minute ago, mC HULL said: the flywheel side seal is easy to spray easy start or carb cleaner etc around it see if it changes the note mate i always stick with cast pistons were i can Why stick with cast mate? Quote Link to post Share on other sites
mC HULL 10,440 Posted March 30 Report Share Posted March 30 1 minute ago, poxon said: Why stick with cast mate? you will have tighter clearances with cast mate forged expand more so you will have more chance of damage piston slap when the engine is cold even if the owner is sensible and warms the engine before giving it any hammer i’d still choose cast my self mate but sometimes all you can get is forged just warm them up is all you can do Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 1 minute ago, mC HULL said: you will have tighter clearances with cast mate forged expand more so you will have more chance of damage piston slap when the engine is cold even if the owner is sensible and warms the engine before giving it any hammer i’d still choose cast my self mate but sometimes all you can get is forged just warm them up is all you can do Our right mate I’ll have to wait an see any how I haven’t even opened the engine up yet I don’t know if it’s buggered the cylinder up or not but the colour of the plug it wouldn’t of been long before melt down happened 1 Quote Link to post Share on other sites
mC HULL 10,440 Posted March 30 Report Share Posted March 30 (edited) 6 minutes ago, poxon said: Our right mate I’ll have to wait an see any how I haven’t even opened the engine up yet I don’t know if it’s buggered the cylinder up or not but the colour of the plug it wouldn’t of been long before melt down happened the kawasaki stuff is normally easy to get old ktm i’ve just had to buy a second hand bottom end for a roller bearing can’t get it i just hope it’s ok when a split the cases lol piston had to be forged no sells a cast Edited March 30 by mC HULL 1 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 6 minutes ago, mC HULL said: the kawasaki stuff is normally easy to get old ktm i’ve just had to buy a second hand bottom end for a roller bearing can’t get it i just hope it’s ok when a split the cases lol piston had to be forged no sells a cast Getting harder to get bits for the o3 kx but plenty of pattern parts about bloody he’ll bet the bottom end wasn’t cheap I tryed buying a f****d 03 bottom end the guy wanted £700 for it the thing is with these mx bikes there worth more in bits loads of people are buying up cheap bikes to brake up for parts 1 Quote Link to post Share on other sites
mC HULL 10,440 Posted March 30 Report Share Posted March 30 4 minutes ago, poxon said: Getting harder to get bits for the o3 kx but plenty of pattern parts about bloody he’ll bet the bottom end wasn’t cheap I tryed buying a f****d 03 bottom end the guy wanted £700 for it the thing is with these mx bikes there worth more in bits loads of people are buying up cheap bikes to brake up for parts ye mate it can be hard work getting parts the bottom end wasn’t bad i was lucky 60quid crank would need rebuilding but if the bearings good it’s served it’s purpose 2 Quote Link to post Share on other sites
poxon 5,555 Posted March 30 Author Report Share Posted March 30 1 minute ago, mC HULL said: ye mate it can be hard work getting parts the bottom end wasn’t bad i was lucky 60quid crank would need rebuilding but if the bearings good it’s served it’s purpose That’s cheap mate good find for £60 you’d make that back selling the cases an gearbox separately out of that 1 Quote Link to post Share on other sites
mC HULL 10,440 Posted March 30 Report Share Posted March 30 11 minutes ago, poxon said: That’s cheap mate good find for £60 you’d make that back selling the cases an gearbox separately out of that hopefully get the engine together this week if i get an hour i’ll bang a few pics up 1 Quote Link to post Share on other sites
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