Question about 2003 Suzuki RM 125

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Oil leak. Transmition oil into crank and combustion chamber.

I have a 2 stroke yamaha rd 125 lc mk2 and i have an oil leak caused by transmition oil entering the crank through the oil seal which I changed previously now it has happened again causing oil to go into cumbustion chamer making it leak from the exhaust; it smokes a lot too. why does the seal keep letting oil through? There doesnt seem to be any sign of wear and it looks reasonably tight. Any ideas? I was just planning on changing it again and hoping for the best.

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Seal in the right way? It's like a one way door!

Posted on Jul 11, 2009

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Without being rude - because you didn't do it properly. There may have been a little bit of dirt or something - it is enough to make the seal ineffectual. The pressure from the crankcase pressurises the gearbox, then oil gets pushed back into the crankcase.

Posted on Jul 01, 2009


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1 Answer

Yamaha rd 350 lc

Is it possible you have an exhaust valve stuck open or not seating properly? That would cause the fuel to run out of the combustion chamber and into the exhaust pipe, before the spark plug can ignite it. Just something to check out. Good luck to you.

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White smoke in a yamaha 125 ttr dirtbike

Hi, Anonymous your instrument gauges and lights can alert you to most electrical and engine issues they can not warn you about failed engine gaskets or seals so your engine has to resort to old fashion alert methods of colored "SMOKE SIGNALS" here is a breakdown of their meaning:
1. COLORLESS OR SLIGHTLY BLUE SMOKE on start-up means your air/fuel mixture is at the right composition and everything is well burnt in your combustion chamber.
2. BLUE SMOKE on start-up is usually caused by failed valve seals dripping oil into the combustion chamber when the engine is not running.
3. YELLOW OR BROWNISH SMOKE at start-up means your air/fuel mixture is too lean. Too lean means that there is low fuel but high air mixture in your combustion chamber.
4. WHITE SMOKE on start-up may be caused by a blown head gasket allowing coolant to enter the combustion chamber and may start dripping out of the exhaust pipes or mufflers. Smoke while riding is usually caused by worn out or damaged valves, seals, guides, pistons, rings, or cylinder walls.
5. BLACK SMOKE on start-up is usually caused by too much fuel in the combustion chamber this can be due to air/fuel mixture adjustment too rich, accelerator pump improperly adjusted, faulty choke/enrichner or not in the off position, air filter dirty and clogged, faulty carburetor float needle and seat, pilot jet too large, fuel injectors leaking, smoke while riding is usually caused by the main jet being too large or a damaged carburetor.
It should be noted that aggressive or abnormal throttle operation will cause these conditions to manifest themselves exponentially.
For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
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Ttr 125 Smoking Problems
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YAMAHA TT R110E Owner Manual

Apr 06, 2012 | 2006 Yamaha TTR 125

1 Answer

Gear oil is getting in combustion chamber and engine is smoking ...this problem happens the whole time engine is running...

Tell me.Are you losing gear oil out of the gearbox???
Reason I ask is there is no connection between the gearbox and the combustion chamber.
The g/box is a sealed unit.It's a 2 stroke motor,not a 4 stroke.
Come back to me on this and I hope I can help

Mar 30, 2011 | 2003 Yamaha YZ 125

3 Answers

Jst gt dtr wen my bands kick in its spluttering and theres no power

being a 2 stroke it has a lot to do with fuel mixture if you mix your own gas try mixing less if its a oil pump theres a screw on the carb fairly big turn it a little to the right and see

most important let it warm up

Mar 24, 2011 | 2000 Yamaha DT 125 R

1 Answer

Does th reed valves cause the bike not too turn on

if you mean not to start they could. a reed valve is simply a one way valve that captures the air fuel mixture in a two stroke motor forcing to go into the combustion chamber rather than back out the carb

Oct 02, 2009 | 2004 Yamaha YZ 125

1 Answer

Tapping sound on top end of engine

sounds like a piston noise, you may have a scoured cylinder, this is common on two strokes.

Aug 13, 2009 | 1979 Yamaha RD 250

1 Answer

Putting wrong transmition oil in yz 125

Nothing significant, don't worry about it. You do NOT want oil marked EC, signifying energy conservation. Such oil will cause the clutch plates to slip and premature clutch wear. If the oil you put in does say EC on the small round type seal simply drain it out and put in the correct oil. Not critical but the sooner the better.

Apr 19, 2009 | 2003 Yamaha YZ 125

3 Answers

What oil should i have in yz 125 2 stroke

The clutch and gearbox share the same oil. The oil for the motor is 10w40. Stick with the major brands; Pennzoil, Quaker State, Mobil, Yamalube or Shell.

Apr 19, 2009 | 2003 Yamaha YZ 125

1 Answer

Wont stay running with out the choke on

it sounds like you need a carb clean performed. the idle cuciut jet is probably dirty and that is the jet that supplies gas to the combustion process at idle rpm's. when you have the choke pulled out it is adding fuel and air so when you shut off the choke the fuel supply goes away. for the oils use yamalube 2 stroke oil for pre-mix and 10w -30 gear oil for your tranny.

Dec 17, 2008 | 2003 Yamaha YZ 125

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