250 MAR - NO NUETRAL

[ColinPybus]

Hello All, Recently rebuilt my engine, but I can't find neutral. Can change through the box using the kick-start,  but it's always in gear. Any ideas? Thanks.

[woody]

Not sure what you mean by always in gear, if the box will go from 1st to 2nd and vice-versa you're going past neutral. With the bike in neutral the final drive will still turn due to drag on the gears. Put the bike in first gear, then whilst turning the engine gently pull the gear lever up but not hard enough that it goes straight to second, or just tap it gently up with your hand. Hold the final drive with one had and turn the engine, if the box is in neutral the drive won't turn, if it's in a gear you won't stop the final drive turning. It might take a few goes to get neutral, much easier with the engine in the bike and rocking the bike backwards and forwards

I'm assuming the detent plunger is fitted and working properly

 

[ColinPybus]

Thanks again Woody for getting touch. Engine is in the bike , I'll take it off the bike lift and try it. Yes the plunger is fitted. 

I'll let you know how I get on.

Best regards,  Colin. 

[woody]

If the engine is in the bike, put it in 1st and try just tapping the gear lever into neutral with your heel whilst rocking the bike. If the shimming is making the gear selection a bit stiff it could cause the selector to go straight past neutral to 2nd and vice-versa. Tapping it with your heel should move it just enough for neutral. It's how I get neutral on my 250 as the gear selection is a bit stiff, my 350 gets neutral a lot easier

[ColinPybus]

Thanks Woody, you got me thinking,  and I realised  the gear change lever shaft had far too much end float so the plunger was not engaging with the selector drum detent. All sorted now , I just can't get it to spark!

[woody]

The end float on the gear shaft won't affect the plunger as that acts on the selector drum, but too much end float on the gear shaft means the selector fork is not in contact with the selector drum when the shaft moves too far to the left. Inside the clutch case there are two washers on the gear shaft, normal and wave washer, located by a circlip. These restrict the shaft end float, if they aren't there the shaft will continue to work its way outwards, disengaging with the drum, nothing that a kick with your heel won't solve to push it back in though

[ColinPybus]

Thanks again, how can I determine if my coils faulty? I've a digital multimeter but have limited knowledge in it's use. I can check for resistance, ohms and voltages. Do you know of any readings between the spade connectors themselves and either spade connector and the ht lead? I get a reading of 049 when I probe the spade connectors and the meter makes a noise.

[ColinPybus]

Testing with the ohms resistance at 200 I'm getting 34 ohms.

[woody]

Sorry I'm useless with electrics so no help with testing electrical components. The 5 speed manual is available to download which should have readings in it.  Or you can send the stator and coil to Bradford ignitions as he can test and repair Motoplat stators and sometimes coils

If your wires still come out from the bottom of the ignition casing and run under the engine, there's a chance that they may have got chamfered or broken as they have to bend a sharp 90 degrees, once old and brittle the sheath can crack causing shorts or they can just break. Also, with a bike that's used hard the bash plate gets smashed up towards the engine and can help break the wires. A mod to stop this is to drill a hole through the top front of the casing by the engine mount and run the wires behind the stator, through the hole and up the front frame tube. This involves grinding away some of the ribbing behind the stator to accommodate the wires.

If your bash plate has go bent upwards, also worth checking that the head of the sump plug bolt isn't exposed as that can end in tears if it catches a rock. Tapered headless allen bolts solve that problem