Starting issues

[Bitten]

Hi all

Any suggestions to my starting issues would be greatly appreciated

I have just finished restoring an RM 465Z - including a full engine rebuild and it does not want to start....

Check list:
Good strong spark (new NGK as per the manual)
Fuel seems to be going through OK (BP98 @ 20:1 with Castrol TTR synthetic)
Strong compression
Engine turning over smoothly

I pull the choke on, on the 2nd or 3rd kick if wants to fire up, a few strong engine crackles then nothing, I kick it 20-30 times and nothing not a mumur??

I left it over night, rechecked everything, it looked like a fair bit of fuel has leaked from the overflow tube from the carby so I pulled it off, reset the float levels gave it a good blow through with contact cleaner. Checked the spark plug and strong blue spark. I did the same as above and same thing, on the 2nd or 3rd kick there were  a few strong engine crackles then nothing again I kick it 20-30 times and nothing.

Do I try and clutch start it down a big hill or am I just missing something obvious

Any thoughts as diagnostics are not my strong point!

Thanks in advance

[Bitten]

Further to this I just went out and recheck and more fuel is slowly leaking from the overflow tube on the carby.

I know not too far ago there was a thread about something similar but do you think I can find it!!

Is this connected to the starting issues or something else all together?

Again any assistance is greatly appreciated

Regards

[Slakewell]

The fuel issue could just be needle and seat.
Recheck all electrical earth places , when you painted the frame did you leave it bear under the coil? Is the stator backing plate nice and clean and on a unpainted surface.
Could be a huge air leak somewhere as well. Take off the Carby and the pipe , tip fuel into the inlet about a good cap full and kick her in the guts , if it fires up you at least know its not spark or air leak.

[VMX247]

Check list:
 Checked the spark plug and strong blue spark.

I'm with Slakewell the bar tender,check wiring,timing,cracked rubbers...recheck & check !!
good luck

[Slakewell]

One thing that I do because I'm very lazy and like my bikes to start easy is to add an extra earth wire from the coil to the stator plate. Even more so with old motoplates. 

[pancho]

 Try another new plug, Ive been caught with a crook brand new ngk on my RT1
 cheers pancho.

[KTMaico]

One issue that can catch out a re-build is, everything looks good to go and you can't work out what is wrong.... Good Spark, Fuel getting in (Wet Plug), Compression OK. Check that you have no air leaks getting into the cylinder via carby mounts, decomp valve etc... as this will lean out your mixture to a point where it will be very differcult to start. Also Check that you have the correct size pilot jet or your pilot jet is not blocked. If all else fails, buy a Maico 490.

Kevin

[D project]

Had the same problems with my RM500 when I restored it. With all the kicking over you may have a lot of excess fuel in the crank case. Check to see if you get a wet plug. You may need to drain the cases. I found that was my problem. Also you really need to get a good kick over at top dead center.They are always a B##ch to start.You could always try the old roll or tow start if you are desperate.But even then it is hard to do without locking up the rear wheel. Good luck

[oldyzman]

If the crankcase has a gut full of fuel, i would remove the plug give it a couple of slow kicks, dry the plug, put it back in. Try to start it with the throttle wide open. If you can get it to fire up be careful, it might start to rev its tits off. Just get ready on the kill switch, as it starts to rev up kill it momentarilly until it slows down then release the kill switch.

I once rebuilt a yz250F, i put the coils the wrong way around, ie the high speed in the load speed position.

Good luck brett

[Canam370]

If you have the plug out and are kicking it over to clear the lungs.......its obvious BUT don't forget to hold the kill button on or disconnect the electrics. If you don't fry the CDI then you might just fry the bike (fuel and spark!). I've seen it happen

[KTMaico]

Another option if you are sure everything is correct is take out your air filter and use a can of "Start Ya Bastard" This will get the bike to fire. If everything is OK the bike will run, if not it will just fire and cut out. At least then you know you can look at the fuel and intake and rule out the ignition and timing. I hope this helps.

Kevin

[YZ250H]

Have you checked the timing with a timing light ?

[bazza]

elimination
spark - compression and petrol

[Bitten]

Thanks guys I will go through each of these and give it a try before I give up and pay someone to sort it out!!

Re some of you questions (Forgive me if some of my answers are pure ignorance!)

I have gone over it with a fine tooth comb and no obvious cracked rubbers or air leaks

The frame and coil mounts are powdercoated under the coil - Is this an earthing issue? The wiring diagram for this model shows an earth lead off the coil but the only earth lead that I have is from the kill switch which is onto a bare bit of frame

The manual states that the timing can't be adjusted on the 82 model and the stator was replaced in the correct position, so I am assuming timing is OK

I did check the spark and looks to be a strong blue arc on a correctly gaped new NGK spark plug

As I have a strong spark am I safe to assume that it is not electrical in nature

I will give some of the other tips a go and see what happens

I'll keep persevering for the time being

Thanks again

[VMX247]

am I safe to assume that it is not electrical in nature

No..never trust one wire 
reading post reply 122-130
http://ozvmx.com/community/index.php?topic=6469.120
Always a prosess of elimination-its vintage we have time. 
cheers A