Another 2 Stroke Problem :P

[Sheep Dags]

Hey guys,

I've just gone out and done something silly... I bought a TZR250, well because it fuckin kicked ass!... which seemed sweet when I bought it but gradually wouldn't start so easily, now hardly starts at all, unless I push it for miles and miles. I changed the plugs and even the battery cause it was flat but that didn't help. Was telling a guy at the garage exactly what I just said and he reckons it's a problem with compression, cause yea, when I kick it, it doesn't feel as though anything is happening. Anyway so he reckons it's siezed!! - I don't know exactly what happens when a 2 stroke siezes but i know it's BAD and COSTLY. Does anyone know of any 2 stroke whizzes out there who wouldn't mind having a look for me to see what's up, and to see whether I've bought a lemon or not Cheers heaps
- Mike

P.S. I'm out at Torbay in Auckland but can transport it in my van if need be

[White trash]

Hey guys,

I've just gone out and done something silly... I bought a TZR250, well because it fuckin kicked ass!... which seemed sweet when I bought it but gradually wouldn't start so easily, now hardly starts at all, unless I push it for miles and miles. I changed the plugs and even the battery cause it was flat but that didn't help. Was telling a guy at the garage exactly what I just said and he reckons it's a problem with compression, cause yea, when I kick it, it doesn't feel as though anything is happening. Anyway so he reckons it's siezed!! - I don't know exactly what happens when a 2 stroke siezes but i know it's BAD and COSTLY. Does anyone know of any 2 stroke whizzes out there who wouldn't mind having a look for me to see what's up, and to see whether I've bought a lemon or not Cheers heaps
- Mike

P.S. I'm out at Torbay in Auckland but can transport it in my van if need be

You poor bastard!

Yamaha 2 stroke parts cost a fortune. Tow it to a bike shop or any work shop for that matter and get them to perform a simple compression test.

Wont cost much but the repairs probably will. I'd be happy to help with repairs but it's a bit far to commute.

[Sheep Dags]

thanks for the reply,

Does a lack of compression definately mean it's seized or could it just mean there's somthing else wrong with the engine? i.e. something not so expensive

- plus, if I actually DO get it started very occasionally doesn't that mean it's not siezed? seeing as I can take it for a ride etc etc, just when i next try to start it up it won't go again

[Two Smoker]

thanks for the reply,

Does a lack of compression definately mean it's seized or could it just mean there's somthing else wrong with the engine? i.e. something not so expensive

- plus, if I actually DO get it started very occasionally doesn't that mean it's not siezed? seeing as I can take it for a ride etc etc, just when i next try to start it up it won't go again

Lack of compression could mean that your rings are gone, still costly though:confused2 . If you want to save $$$, get a manual take it apart and see what the problem is, as long as its something like a Haynes manual you can't go wrong

[FzerozeroT]

if it's seized you wouldn't be able to kick it over, if you have any mechanical nounce (and a torque wrench handy) pull the head off, just the top not the barrell, inspect the cylinder walls, top of the piston, and combustion chamber (take photo's if you can) then tell us whats happening.

edit:

use the torque wrench to take it apart, if the nuts are unevenly tightened then the guy before youcould have swapped the rings from one cylinder to the other or something else dastardly, someone that low wouldn't bother to use the proper tools either (SCUM) look for anysigns of a cheap fix-to-sell job

[curious george]

Give me a ring. I'm in Devonport, so can ride up after work or summit.
Pm'ed

[Andrew]

Speak to Dave. Dave all the way!

[Wellyman]

Hey sheep dags I got half maybe a full TZR 250 motor and live in Auckland give me a PM if you need parts because I might have them!

[speedpro]

If someone has been messing with it prior to sale they could have reused the piston circlips and they could have come out. You also haven't mentioned the injection oil, either because it's too obvious or you don't know to check it. They're good bikes but must be put together properly. I have all the tools so if you get stuck let me know, plus Henderson Yamaha is just down the road - for bits.

[Sheep Dags]

Thanks heaps guys,

I've got a receipt here from Mt Eden motorcycles from when he took it in to get the rings replaced so they have done that but maybe they fucked it up when they put it back together or something I dunno, and I'm sure if there were big problems with it they would have noted it.

George I'll give you a call tomorrow but won't be able to meet with you cause I'm busy after work but would definately be keen Thursday.

and I'll definately consider the offers of parts etc etc
thanks heaps I'll let you know what happens.

[pete376403]

A full-on siezure will lock up the motor and it will stay locked, even after its cooled down. Your motors lack of compression indicates its had a partial siezure and piston ally has been smeared up over the rings, wedging them in the bottom of the grooves. New piston and ring pack time, plus rebore. If your motor uses chrome plated bores it's prolly going to cost you big time (Desperate - ie Friday night before a ride and no spare rings in the country - people have been known to extract rings from pistons and reuse them).

Usually caused by running too lean / air leak in the inlet manifold, etc. Running out of oil (in a bike which uses a seperate oil tank and pump system), the crank is more likely to fail before the pistons.

Adding more oil (beyond the correct ratio) in a premix bike will not help - if anything it will make matters worse - if the motor is running lean and you increase the amount of oil going through the carb jets then at the same time you must be reducing the amount ot fuel going through ie even leaner than before.

[MrMelon]

He didn't say there's a lack of compression.. every now and then it'll start and be running like it should, but it's just impossible to start, so it shouldn't be seized at all?

[Sheep Dags]

yea definately gotta be a lack of compression but what I don't understand is that once I finally get the fucker started, it goes sweet, i mean i can take it for a thrash and it's all good. just getting it started is a real cunt!

[Two Smoker]

yea definately gotta be a lack of compression but what I don't understand is that once I finally get the fucker started, it goes sweet, i mean i can take it for a thrash and it's all good. just getting it started is a real cunt!

Maybe your pre ignition has gone kaput, get that checked out.

[pete376403]

Maybe your pre ignition has gone kaput, get that checked out.

What do you mean by "pre-ignition". That phrase is usually used to define uncontrolled ignition, aka 'pinging' or 'pinking', and in the worst case, 'detonation'. Expect to find the piston crowns all over the crank shortly after that starts.