Yamaha TZR 125

[Vykintas Dancevi�ius]

Hi fellow associates. My name is Vykintas and this is my first post here.

I own a 91 Yamaha TZR 125. And all I can say is, my bike is just great!

Ok, getting to the point here..

The bike is ok, acceleration, top speed is good, no strange sounds coming out of it, everything seems to be fine, BUT. If I leave it for a two weeks or more and then come back to my garage, try to start it up, it doesnt start. I checked the battery, the spark plug, fuel. Tried the choke too. My garage isn't cold, everything seems to be fine. I need to push it, run along with it, jump to the 1st gear few times to start it up. After five minutes of warming it up it starts just fine.

I'm thinking about the piston and the rings, maybe they didn't have enough lubrication and the compression went down? Becouse I mix the oil with fuel manually. Blocked the oil pump and mixing it with domensional syringe, just to be sure. The ratio is 1:50 (1ml oil to 50ml fuel) Or maybe something with the combustion wires?

If You had the same problem, please reply. Other suggestions are acceptable too.

Thanks for Your help, guys. May the season come faster and good luck on the road.

[Speedshop]

Pre mix will make the mixture lean. have you rejetted the carb to account for the oil taking place of petrol. I suggest you reconnect the oil pump, it will give the engine better protection then premix can.

[YPVS TONE]

Does your bike have a "PRI" or Prime position on the fuel tap ? On my 350 YPVS I find if its not run for a week or more the carbs need filling up by turning the tap to the prime position for a few seconds then back to the ON position. After this it will start 2nd or 3rd kick. Also worth remembering when starting from cold use choke and NO throttle. I agree with Speedshop on the oil pump. Why use premix as the autolube system is usually very reliable provided it is correctly set up and not allowed to run out of 2 stroke oil .Tony.

[Cynic]

Hi fellow associates. My name is Vykintas and this is my first post here.

I own a 91 Yamaha TZR 125. And all I can say is, my bike is just great!

Ok, getting to the point here..

The bike is ok, acceleration, top speed is good, no strange sounds coming out of it, everything seems to be fine, BUT. If I leave it for a two weeks or more and then come back to my garage, try to start it up, it doesnt start. I checked the battery, the spark plug, fuel. Tried the choke too. My garage isn't cold, everything seems to be fine. I need to push it, run along with it, jump to the 1st gear few times to start it up. After five minutes of warming it up it starts just fine.

I'm thinking about the piston and the rings, maybe they didn't have enough lubrication and the compression went down? Becouse I mix the oil with fuel manually. Blocked the oil pump and mixing it with domensional syringe, just to be sure. The ratio is 1:50 (1ml oil to 50ml fuel) Or maybe something with the combustion wires?

If You had the same problem, please reply. Other suggestions are acceptable too.

Thanks for Your help, guys. May the season come faster and good luck on the road.

Going old school here, the oil may be dropping out of the fuel and laying in the carb etc, try when you are on the very last bit home, closing the fuel tap so you run out of fuel as you stop. Then give the bike a shake before you turn on the fuel.

I know modern oils are better than they used to be but we used to do it back in the day.

Other than that, the symptoms suggest a minor air leak on the carb side of the motor somewhere, or, worse case a crank seal.

[Airhead]

Greetings Vykintas

If youre concerned about compression then why not do a compression test on the bike, you may be right.

50 to 1 sounds a bit sparse on the oil to me though but if you know best.

I too am a fan of pumped lubrication

[Vykintas Dancevi�ius]

First of all, thank You very much for Your replies, guys.

Pre mix will make the mixture lean. have you rejetted the carb to account for the oil taking place of petrol. I suggest you reconnect the oil pump, it will give the engine better protection then premix can.

The bike is pretty old (1991m) and I'm not so sure about the pump's reliability. I have one fella who has a TDR (the motors are identical) and his oil pump went wrong, he had to change the piston two times. So thats what basically scares me off.

Does your bike have a "PRI" or Prime position on the fuel tap ? On my 350 YPVS I find if its not run for a week or more the carbs need filling up by turning the tap to the prime position for a few seconds then back to the ON position. After this it will start 2nd or 3rd kick. Also worth remembering when starting from cold use choke and NO throttle. I agree with Speedshop on the oil pump. Why use premix as the autolube system is usually very reliable provided it is correctly set up and not allowed to run out of 2 stroke oil .Tony.

What does "PRI" mean, anyway? My bike has "RESERVE", "ON" and "OFF" on the fuel tap. (If we're talking 'bout the same thing ) And yes, I tried the choke with no throttle.

Going old school here, the oil may be dropping out of the fuel and laying in the carb etc, try when you are on the very last bit home, closing the fuel tap so you run out of fuel as you stop. Then give the bike a shake before you turn on the fuel.

I know modern oils are better than they used to be but we used to do it back in the day.

Other than that, the symptoms suggest a minor air leak on the carb side of the motor somewhere, or, worse case a crank seal.

I don't know how the oil could go out of fuel in a week or so. I've seen a mixed up fuel who was hold up for a year with no oil/fuel sepperations detected.

I was thinking 'bout the closing the fuel tap and burning the fuel out of carb trick too, but doesnt that do damage to rubber? (I don't know how to recall it, but I hope You understand what do I mean :s )

The biggest proplem is that my bike is 150km away from me. So till then I want to gather all helpful information and thoughts about the spring technical maintenance.

Thanks again, waiting for Your answers.