Some help needed. No spark!!

**Thu May 05, 2005 9:37 am » Post: #1 » Download Post**

hi all,

my 1988 NSR 250 MC16 has started only running on one cylinder.
Im not getting a spark at the lower plug. Ive tried all the usual things, and ive swapped over the coils to check its ok, and they are.

So i guess the problem lies between the CDI and the spade plugs for the coil.

Has anyone got any ideas or suggestions? i dont like the idea of tracing those wires back.... Sad

help please!

**Thu May 05, 2005 10:50 am » Post: #2 » Download Post**

have u tryed a new plug. i had a problem with my lower cylender and it was just the plug i changed everything exept it Rolling Eyes

and the plug was just to wet so it was shorting rather than sparking.

**Thu May 05, 2005 11:23 am » Post: #3 » Download Post**

yes ive tried a few different plugs.
btw, is the CDI unit under the little compartment with the plugs and connectors at the top of the frame?

**Thu May 05, 2005 11:38 am » Post: #4 » Download Post**

on a mc 16 no that is for power valves. they are under the tank under the little black tray that has all the conectors and power valve servor on it.

**Fri May 06, 2005 8:52 am » Post: #5 » Download Post**

the MC16 has a cdi for each cylinder and they do pack up. try swopping the cdi,s over.

**Mon May 09, 2005 9:27 am » Post: #6 » Download Post**

um i think there is just one CDI unit in my bike. Which has a connection on each side for each coil .

ive spent alot of time on this, and i thought i had narrowed it down to the plug on the cdi, for my lower cylinder, but by the time i had put the petrol tank back on, the spark had gone.

It seems very intermitten. Is it safe to swap the 2 plugs on the CDi unit round, so i can narrow the problem down.

ANy ideas please.!!

**Mon May 09, 2005 9:47 am » Post: #7 » Download Post**

it may look like one but it is two. they are in a rubber sleve. you can pull them out and change them round to check the spark.

**Mon May 09, 2005 11:18 am » Post: #8 » Download Post**

ahh, yes. now you say it, i can see that there are 2.! duh!

so now i can at least swap them round to check.

Another thing, the guy i bought the bike off, gave me a wiring diagram for a mc18, but the bike is mc16. How can i tell what wiring loom is in my bike? i think he may have done some mods to it, so possibly hes put a later loom in.

btw, anyone selling a CDI unit? in case it is my problem....

**Mon May 09, 2005 8:46 pm » Post: #9 » Download Post**

if it has the two cdi's its a mc16 coz the mc18 has a single cdi called a pgm1 and then they go up with the models to pgm4. the mc 18 digram i would think is use-less but here is a mc 16 one u can download

http://www.dreamgate.ne.jp/nsr/service%20manual/wiringdia/mc16wiring.html