No spark in spark plug from cilinder nr 4

[Cedric]

Hi,

I need some advise please. Bike ran poorly, lacking power. Not on all cilinders. 

I've used an ignition timing light gun to test the ignition on the spark plug wires. 

nr 1 seemed to give less light flashes, but dificult to judge

nr 2 ok

nr 3 ok

nr 4 no light flashes.

I've orderded new spark plugs, figured it will never hurt to replace those. But if prblem is still there, could it be the ignition coil? Or wires? What are good replacement products?

 

Thanks!

[Duckndive]

Given 1 & 4 are the same coil .. i,d start there 

Try the suspect plugs on the other coil if they spark its a duff coil 

[TonyGee]

yep, suspect coil or wiring to it. 

[Cedric]

With new spark plugs all four give a spark!

BUT

I can't get the spark plugs out. Ive got an 18mm spark plug spanner but I can't get it deep enough in the hole. The hole is to tight. 

Does it require a specialist tool? (Outside diameter of my tool is 26 mm)

[Gixer1460]

Yes - you either get a box spanner like what comes in bike tool kit or a thin wall socket or get yours in a lathe and thin it down!

[george 1100]

Once upon a time a got a grinder around the outside of a socket to reduce the size

[TonyGee]

1 minute ago, george 1100 said:

Once upon a time a got a grinder around the outside of a socket to reduce the size

yep done the same !!!  when you are in a rush and till the correct  socket turns up.  

[Duckndive]

3/8" drive 18mm long socket normally works 

[Dezza]

You can buy extra long plug sockets in various sizes. I have a couple. Look on eb@y. Be especially careful with sizes though as plug socket sizes are, I think the thread size, not AF. It's easy to buy the wrong one .

Edited August 1, 2024 by Dezza

[Cedric]

With the angle grinder I modified a tubular box spanner. Changed all the spark plugs. Bike started imidiatly, runs smoothly. Thanks guys!