help with starting XL250

[dastardly]

Hello all, i wonder if you can help me before i start using a hammer...?

I have posted a number of other threads about a xl250 degree and i wonder if anyone can help me with this problem i have now?

I have replaced the CDI, cleaned up all the bad connections and the loom, now i have a spark, thats bright and looks right.

I have started the bike and it will run (occasionally) only from cold, or if i remove the spark plug (its a new one) and clean it up.

The bike has a keihin CV carb, that i have removed and cleaned up with carb cleaner and all the passageways and jets appear to be clear, i removed the pilot jet and checked that, refitted it to 1.5 turns as per the NX250 manual (cant find a degree manual anywhere).

If i do manage to get it started it wont idle, it doesn't smoke alot, but it will run until you let it.
After then it will not start, if i remove the plug it looks black, if i clean it up it will start after alot of cranking (electric start).

JUst wondered if you have any suggestions - i hope its not oil that i can see?

Cheers all
Rob

[StumpyFingers]

Check that you have replaced the choke the correct way around.
Also check the air filter / path to the carb(s).
The symptoms you describe are as if the choke is permanently on.

[dastardly]

Thanks for the tips!
I've checked the air ways and all appears to be correct, the choke is a cylinder that inserts into the carb, doesn't seem like it can go any other way around.

I've taken the plug out and it sparks from the electrode to the side of the plug until its cleaned up, when its cleaned - then i can get the bike to start - but it still doesn't idle.

Doesn't seem to run well when i do get it going too, i was wondering if this spark plug could be too cold - but its the reccomended one for the bike?

[StumpyFingers]

You could try a hotter plug , Recheck the pilot jet, it may look all right but if it is set only slightly out the bike will not get sufficient mix to run correctly.

Any thing else and I am stuck.

[datsun fan]

I bought a trials gas gas 160 a while back, and it suffered from running rich, every section I had to change the plug so carried about 12 in my pocket to get round the course!

Obviously this was a mega pain, and we went through everything, being a stroker, crankcase seals, jets, needle heights, air filters, the works, eventually on the internet I came across "the gasgas Guru" in California, and it was traced to the incorrect "D" cut away profile on the airslide.

I don't know anything about CV carbs, maybe they don't have needle positions or slides, the point is, if they do check them, if they don't - you have to check everything - even the unobvious, what w@nker changes the carb slide - took weeks to nail it down to that, but put the right one from Dell orto in and it runs like a dream!

[catteeclan]

Do you mean the piolet screw at 1.5 turns and not the jet?
Could be worth checking the choke is all the way off so the plunger is seating and the plungers seat is undamaged. Should be rubber on the bottom if I remember right.
Maybe check the jet sizes against another 250 carb.

[dastardly]

Yes sorry i did mean the pilot screw rather than the jet, i'll check the jet sizes too...

Don't you think that the problem may be related to the plug at all?

[catteeclan]

Yes sorry i did mean the pilot screw rather than the jet, i'll check the jet sizes too...

Don't you think that the problem may be related to the plug at all?

I don't think so but could be wrong.
If the plug is black/sooty it's got to be rich, black and wet could be oil but you'll normally get blue smoke with it.

[StumpyFingers]

Yes sorry i did mean the pilot screw rather than the jet, i'll check the jet sizes too...

Don't you think that the problem may be related to the plug at all?

The signs are for running too rich, the plug is only showing the signs , it is not the cause.

[dastardly]

i've checked the jet sizes, the main jet is 118 and the pilot is 35, i cant find an online place to check if this is correct.
I took the bike out for a spin once i got it started and it pulled really well once it got going, but still wont idle and start after you stop it.

what do you think i should do now? I have cleaned the carb again, the throttle valve was black so i have cleaned this up and it seems to slide better.

I have check the choke and it does have a rubber at the end of the plunger, but im not sure how to check to see if this is sitting correctly?

cheers again..!