hi please can somone help me. i dont have a manual for my 97 dt125r and it needs a top end rebuild please could some one give me a step by step guide. also i just bourght a pwervalve servo and all the fittings and pullys.( it works) nealy new £35:) thanks.
its an easy job! take the tank and seat off, loosen the engine mounting bolts an remove the 2 front ones, also the head brackets take them off. loosen the swingarm spindle an push it out with a steel/wood drift. loosen the head nuts(4 flanged nuts) take the cylinder head off, put the bike in gear and roll it back and forward untill the piston drops down as far as it will go, or if u have a kickstart push it with your hand until the piston reaches this position. loosen the 4 flanged nuts holding the barrel. tilt the engine slightly and take the barrel off, this will expose the top end
yeah it is quite an easy job for me now. it is easyest done with two people, but for someone like youself its totaly up to you. if you do it yourself, use the haynes manual!!!
Call me stupid but when the top end is re-built what are you actually doing? I thought you would only touch the top end to re-bore or replace the piston? Also how can you tell if you need to replace the pison?
a full top end is new piston, rebore, new rings, new gaskets and seals. (gudion pin, small end bearings) you can measure the piston with a pair of veneir calipers to see how small it is in comparison with the bore. i think. lol
hey there people.. I'm just about to have my first go at the top end tomorrow but i need to know if i need to plug up/ drain out the 2stroke and coolent before i take the topend off? i did take the top end my old one but cant remember if i did that. Wel it was like 7 years ago.
Remove the rad cap and undo the drain plug in the waterpump and drain out all the coolant. You dont have to drain the 2 stroke oil but when you take the 2 stroke oil feedpipe off the carb/manifold (depending on year) you must plug the end of the pipe. As a precuation, drain the fuel tank and refill with a litre of premix to allow time for any air bubbles in said oil pipe to work their way through without starving the engine of oil.
Cool thanks for that Dingle001. Mines a 2001 but the maifold is next to the barrel but not attached to it or anything and then you have a reeds and carb.. I think thats about right lol.. been a long time since i got my hands dirty and im gonna enjoy it.
Yeah I got the online manule that i downloaded so it should be alright. Would you surjest truning off the petrol and running it till the petrol is out of the system? Then drain the coolent and then take the topend off? also when i put the topend back together i was watching a american bloke on youtube that dose loads of vids of rebuilds on bikes. I think it was him that said in his vid that some people tend not to finger the barrel with 2stroke as this makes a quicker running in process. Will take pics tomorrow and make a new post on here.
Don't worry about draining the fuel from the carb, for the top end rebuild you don't need to remove any of the carb assembly! Your coolant will need to be emptied though. I've also watched that same video, and putting premix around the piston only helps to fit everything back in, it doesn't really aid the running in process so to speak. When you buy the piston/rings etc, make sure you fit them the correct way round, they should be marked on the top with a little 'T' on each ring, and they differ in size slightly too. I didn't realise this when I did the top end on mine, I was told this by the chap who honed my cylinder!
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ok thanks for that. Im gettin some bloke to machine the barrel out and he said he can get me the piston as well to he will line up the bore with the piston in and get the right clearance so i can just put it back on. Bloke seemed very helpful. Is there anywhere on here that explains what ring goes where and what way around?
If you ask the chap who is doing you're cylinder hone, I suspect he's probably seen enough pistons to know what ring goes where.
There is also a small crinkly metal ring that goes underneath the bottom piston ring, you'll get it in the piston kit. Don't forget about it!! lol
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yeah slides in the middle and comes out after you take the clips off hehe.. Ive got the top end off now.. Il up some pics in a mo and you can see the barrel, Can you let me know if its needed rebore? thanks
