2 stroke help please

[luckatme85]

hi guys new to the forum so please be gentle.
i own a 1994 ts125r and lost all compression whilst out yesterday, im gunna go take the head off today when rain stops,
my question is though, when i was riding it it always lost power and started to slow down whenever i hit the top 2 gears, it was like it was gunna die on me. if i changed down 2 it would accelerate straight back up into the powerband but as soon as i chnage back up same would happen again, could this have been due to low compression? or could it have been a powervvlve problem?
any help much appreciated
thanks in advance lee

[TGB]

the suzuki TS125 wow havent seen one of those for a log time. right three things to look at ignition the dreded top end rebuild and of course crank seals.

top end: in most cases a new barrel and piston wil be needed. but as its just a steel barrel you can rebore it with ease and fit an over size pistion.

ignition timing: if you are unlucky you will have points and so setting up is a pain. but booking it in to a workshop will cost you no more than £30 + VAT + PARTS

crank seals: when you have the head, barrel and pistion off. fill the crank mouth with diesel and leave it for a few hours. if the level has not droped your fine. if it has the new seals are needed. but these are easy to fit. just remove the flywheel coils ect. screw into the seal a self tapping screw and pull it out then drift in the new one. as for the other side you will need to drain the oil remove the clutch cable, gear lever and then the clutch cover now you will need to remove the clutch it self then behind that is the other crank seal. and you remove that and refit the same way as the other side. when your done refit in reverse order.

thats the quick way. but if your in doubt seek the help of a pro like my self.

[woodie]

sounds more like valve or carb to me .

[MarJay]

[luckatme85]

right guys top end is off and it is buggered, the exhaust port is very thin, the rings have seized solid to the piston and the barrel is scored, only slightly but tbh with the exhaust port as it is top end is rendered useless anyway.
the cause of the seizure to me looks like overheating, this was proved when i removed top end because no water came from main hose as it should when removed.
tbh the engine looks like its had a hard life and not really been taken care of as most 125 2t are these days by learners. it has had restrictor removed from exhaust and probably just thrashed to within a inch of its life by spotty 17 year olds who know nothing, all the ports are carboned up and the exhaust is more like a old coal fire chimney.
someone mentioned that my bike (1994 ts125r) has a steel barrel but when i took it off it looks like it is a nikosil lined barrel?
if it is im sure it would be cheaper and easier just to source a decent 2nd hand barrel off a ts or a rg, i know one of the rg's is the same engine but am not sure which one.
while the engines in bits like it is im just gunna do the crankseals anyway for peace of mind, i also would like to find out which wire it is to derestrict it, not because i want to derestrict it but because i want to re-restrict it, sounds daft maybe to some people but its always gunna be less reliable as a higher power bike so would just like it a bit more reliable, reliable 2t i hear you say? maybe i am kidding myself a bit but nvm.
thanks for advice so far guys it is very much appreciated and if anyone could point me in the right direction of a new barrel in good nick that would be very much appreciated aswell
thanks again lee

[Vincent]

[Vincent]

[MarJay]

[luckatme85]

i get what you are saying bout the barrel but the ports on my original are shagged so a new barrel is the only way i think?

[Blau Zedong]

[TGB]

troll away no attention is being paid.

as for the use of diesel its an easy way to see if there is a leak between the seals it wont hurt any one or any thing. plus diesel wont catch fire like petral there fore safer to use. also the TS125 to my memory did not have niksil nor did it have alusil treated bore but check with a dealer to be sure as we all know how things get changed with out no one knowing till its too late.

aside of all that when i get a bike especialy a 2T thats not running right if at all. i do all the obvious checks ignition, plug/s, compression check, fuel check ect also what no many people do is a vacume check through the intake. but nine times out of ten its top end off for a check and a leak down test on the crank hence the diesel. i dont after 20+ years exp piss around wasteing time questioning everything. i know whats issues as soon as i see it.

[luckatme85]

well ive just been to 2 of my local bike shops and both say the barrel is shagged and the barrel is nikosil lined so. do i try source a new barrel a good 2nd hand one or do i just get this one re-plated and fit a new powervalve? becuase my old powervalve is shagged too, a piece of it was stuck in the exhaust port.
can anyone tell me which other barrel may fit because im having no luck finding one for my model bike. if it was a/c then yeah i can get 10 top ends but for my model nope none.
thanks lee

[P.]

Nikasil can be repaired, but sometimes cheaper to just grab a new barrel.

Was for my RS anywho

[luckatme85]

right heres some pics show you all the damage lol

https://i.imgur.com/KbEhA.jpg
https://i.imgur.com/RTOB6.jpg
https://i.imgur.com/rbqFw.jpg
https://i.imgur.com/pI878.jpg
https://i.imgur.com/SXMNL.jpg
https://i.imgur.com/dAK98.jpg
https://i.imgur.com/XQUrC.jpg


so does anyone think this barrel can be saved?? i think not but theres a lot of you that know a lot more than i do
thanks

[Ivor-Byke]

barrel just needs a nikasil replate decoke the ports and new piston and powervalves, jobs a gud un

[Vincent]

Those PVs look the same as the RGv ones that were also prone to falling apart and falling into the engine. You can get better aftermarket ones i think. Either that or the original ones can be modified. Worth looking into in any case.
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Space Is Deep

[luckatme85]

well after talking to a mate and explaining everything he thinks that i should be able to get the exhaust port welded with aluminium and as the barrel isnt damaged other than port that will sort it
im not sure myself
how much will it be to get it replated roughly as i cant find a 2nd hand barrel anywhere
thanks

[Kickstart]

Hi

Replate will be a bit over £100 (you will need gaskets, piston, etc, on top of that).

I can't really see in your pics, but if the actual bore is scored it will need replating. Damage can be welded up before it is replated.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[MarJay]

The ports look good to me...
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[GrumpyGuts]

On my old '76 two stroke, the fuel petcock was corroded which was preventing fuel reaching the engine at high revs. I thought it was the condenser and points, but no it was that!

Worth checking your fuel lines whilst you're at it!
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My Bikes: Lifan Beat 125cc '11 -> Suzuki B120P '76 -> Suzuki EN 125-2A '08 -> Honda CG 125 '04 -> Honda CB600F Hornet '98 -> Kawasaki ZZR 600 '99 -> Kawasaki GPZ 500S '95 (Current)
Theory test passed - 09/02/2012 >>>> Module 1 passed 24/07/2012 >>>> Module 2 passed 24/10/2012

[luckatme85]

the fuel flow is fine if you look at the powervalves in the picture that was my problem not fuel starvation.
the only port thats not ok is the exhaust port which is very thin so am gunna take it to a local 2t tuner and see if he can do anythng with it or reccomend anyone that can
i plan on getting a new piston, rings and gaskets etc but getting the barrel sorted is top of my priority list right now as without that everything else is useless.
also does anyone know which rg barrel will fit?
thanks again lee

[stevo as b4]

I'd be almost certain that your cylinder can be saved, with a re-plate and maybe welded if required. £120 odd should cover the cost of the work and then £50-70 for a new piston, rings, small bearing and gasket set etc.

I wish i has pics of my KMX200 barrel to show you, as there are some really deep gouges in the bore, where the piston broke up and jammed in the ports. I've shown it to a couple of bike mechanics who have said it's definately repairable, so yours should be too!

I think you need to be more worried about the state of your powervalves, as if they are like the RGV250 ones and they should be, being a related to the RG125FUN and RGV250, then they seem to have serious reliability issues. Personally to justify the cost of an all new top end, id want to buy a set of the special aftermarket one piece valves as insurance really. I can't remember who makes them, but Stan Stephens talked about them in one of his CMM tuning articles recently. I think they are £100+, but look very nicely made and should stop the problem occuring that Suzuki unfortunately never managed to fix.

With the potrs all de-carbonised and cleaned and a de-coked expansion chamber and re-packed silencer, you should have all of the 20 something bhp back and it be reliable as well as pokey.

The bike that has the similar cylinder to yours is the RG125FUN, but the barrel and head do look slightly different so both might be needed, and the porting is definately different between the bikes as is the carb size. Yours has a 27mm TMX Mikuni, and the RG a TM30SS carb i think.

[Vincent]

Might be worth looking at RGv cylinders too.
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[MaybeGuy]

I've seen worse bores re-used with no incidents. I'd just replace the piston and rings, and leave it at that.

Ignore the ''pro'', he's a 'tard. His defence will be something like ''mer mer do it properly'' etc etc, but on a bike that's only worth a few hundred quid, you're a fool to spend the value of the bike getting it running, when you can get away with a £20 piston.

The bridge on the port within the bore is the important part. If that's fine, then I'd just leave it. if not, then unfortunately it needs to be done.
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[luckatme85]

well have you seen the pic of the centre of exhaust port?
do you think that would be ok?
ive run worse on a old kx but this is my daily road legal ride