Question about 2003 Yamaha YZ 125

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Crack in my yz 125 2001 crank case

I have a crack in my yz 125 crank case at the back of the righthand side crank case up the top near the kick start. when the bike not running or idling its fine there is no oil leaking but when the bike revs oil starts to trickle out of this crack. would liquid gasket or liquid metal tix this problem? thanks for any help

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You know aluminum can be welded very successfully now, so best bet is to remove that case and take it in to a good welder..You can ry the quick fix (JB Weld) is what i recommend, but success is rare !....good luck to you my friend...Tim

Posted on May 10, 2009

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Some jb weld shouls work fine on it just get it good and clean no oil or paint on the crack. or find a tig and weld it.

Posted on May 10, 2009


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1 Answer

Struggling to remove right side cover YZ 125. All bolts are removed. Seems stuck near kick start

There is either (depending on the year) 1) A metal tab that pivots over a clip on the frame, In which case the cover must be lifete from the opposite end as though opening a box top, or 2) A grommet in the frame into which a plastic knob or pin on the cover is pushed into to hold the cover in place. The grommet often gets hard and brittle making removal difficult often resulting in the need to break the grommet for cover removal. It is by far easier to break the grommet with a long screwdriver than to have the knob on the cover break. Hope this helps.

Dec 23, 2017 | Motorcycles

2 Answers

I recently bought a yz 125 01, it was working fine until my kickstart wasnt throwing back to the original position, i looked closely and i have cracked my crank case and it leaks oil how do i fix it and...

Is it definetely the crank case, if it is than it is a big job, if its just the outer cover you can start by removing the kick start, cover and anything else in he way and see how much damage there actually is!!! You also have the option of having it welded if parts are too expensive, service manual will give you full details

Feb 14, 2011 | 2003 Yamaha YZ 125

1 Answer

Need to see fuse for fuel relay. locate fuse panel

The Fuse panel is in the cab of the truck, passenger side kick panel. If you lay on the floor and look at the kick panel, you should see a thumb raise in the panel. Pull the panel with the finger raise like a door towards the rear of the truck, the hing would be the a pillar side of the cover.

Once this the cover is off, you will see the fuse panel cover and the fuel inertia switch

Fuse # 34.

If you are having a crank no start issue, press down on the fuel inertia switch button ( on the top, think it is a red button ), and try again.

If not, check the fuse with a meter with the key in the run position ( use the pins on the back of the fuse to a meter and a ground lug is in the kick panel near the floor, should have + 12V DC on both pins on the fuse ).

If the fuse tests good and the fuel inertia switch is in the reset position, next is to check the FPDM ( Fuel Pump Driver Module ) on the cross member under the rear of the truck, above the spare tire.

The FPDM can have corrosion build up under it, causing the PC Board to crack.
This is a picture from my 2006, where the case was cracked, but had not cracked the PCB.
The spare tire cable for the lift is to the right of the picture, the tire on the left is the driver's sode rear tire, taken facing the front of the truck from the rear bumper

The new kit has stand offs on it, to provide some room so the corrosion does not happen ( or happen as much )

This is what the fuse for the fuel pump relay, and the fuel inertia feed power to, to run the fuel pump.

Jan 15, 2011 | 2006 Ford F-150

1 Answer

How do i remover 1993 yz 125 kick start shaft

take the case off and be careful not to drop any gears out the back of the case. Then snap the spring loose and then pull the kick axle gear out. The key is putting it back in. Carefuly line up the clip and square on the back of the kick axle with the holes in the back of the transmision then be sure to push on the gear to see if it popps into place. then bring the spring clockwise to fit into the hole. Besure the spring is pushed all the way back. Now carfully put the case back on.

Dec 28, 2010 | 2004 Yamaha YZ 125

1 Answer

Yzr 125 when trying to kick over the bike, no compression at all. already did full top end

Not to be the devils advocate but if there is absolutely no compression while using a compression tester, you may want to check the top end was correctly installed. Even then, you should have some compression. Your only real other issue would be lower main seals. these are the seals thatseal the crank to the case. if they are bad, you will see oil protrude through them when you remove the side covers and turn over the engine. And again, if the top was done correctly or evan has a piston and rings it will still read something. if your merelyh going by feel of kick, be sure to get a compression tester at yout local autozone

Dec 14, 2010 | 2004 Yamaha YZ 125

1 Answer

My crank case cracked what will i do? thanks

if it is cracked you can stuck it with argon
if it has a hall you need to replace it

Pls vote me to keep me alive

Nov 16, 2010 | 2003 Yamaha YZ 125

1 Answer

How do you change the crank

Pull the engine out of the frame. Remove the top end. Remove left and right side case covers. Remove the clutch, crank drive gear, shift shaft assembly, kick start assembly, water pump, rotor, stator base assembly, sprocket and miscellaneous other small items. Remove all case screws then split the case halves using a case splitter tool. Be sure to install new crank bearings and seals. You can see an exploded diagram of the engine at the following website.Please rate my answer, thanks.

Aug 24, 2010 | 2003 Yamaha YZ 125

2 Answers

How much oil do i put in my yz 250f engine if i droped the oil ?

it should be clearly marked on the engine gearbox casing or if on the dry sump system should have a dipstick on the top of the frame near the steering head main nut.

Jul 17, 2010 | 2004 Yamaha YZ 250 F

2 Answers

On my yz 125 my kick start is jammed

Were you riding it when it jammed because that could mean the that something is sized inside the motor, like the crank or the pistion

Mar 27, 2010 | 2003 Yamaha YZ 125

1 Answer

Crach in my crank case

if you know how to split your case, take the broken case to an engeneering shop that can can do alloy tig welding and get it welded

May 24, 2009 | 2003 Yamaha YZ 125

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