Is a rusty looking cdi the reason my bike won't start?

[David22]

I've been trying to start my week old bike for the past two days which up to then has been running great. I came home from a muddy cycle the day before it wouldn't start and I sprayed the bike clean with a hose. After this clean it ran perfectly. The text day it wouldn't start at all. I checked the carb and it was normal and the spark plug does spark when I take it out. The only way I've gotten it to start so far is to put gasoline at the bottom of my spark plug. The bike won't do cold starts. It looks like there's rust in my cdi where the sparkplug goes in here's a pic. Do I need a new cdi?

 

[GreasyChris]

the rust is not helping. you can replace just the end of the spark plug wire with a new terminal and boot. l would pull your magneto cover over and check to see if the magneto itself is rusted and that the connections are solid as @Greg58 mentioned in your other post.

 

[Greg58]

Hey Chris look at the boot in the picture, looks like it has been arcing. David do you have the screw on adapter on your spark plug? It's hard to tell but it looks to me that the boot you have requires one.

 

[David22]

Thanks for your responses I took the cap off the end of my spark plug as per the instructions and the engine ran great until I hosed it down. Here's my sparkplug.

 

[GreasyChris]

the boot has definately seen better days and it does look like it should have the nipple on the spark plug. a replacement cdi is nice to have as a spare and arent expensive. its always good to have a few known good parts lying around for testing as well. the cdi is probably fine but it could use a new boot and terminal for sure.

 

[Greg58]

Screw the adapter back on the plug and try to insert it in the cap, you should feel it snap into place.

 

[Greg58]

I buy NGK replacement plug boots at the local motorcycle dealer for about $3 each.

 

[David22]

Unfortunately I lost the adapter I'm going to go to Halfords tomorrow to buy a new sparkplug and boot. I don't know what ones to get. I'm stuck between two spark plugs and two boots can someone please tell me which ones I should buy!

 

[GreasyChris]

i suspect your in the uk? id go b7hs and the boot to fit that plug. either look acceptable

 

[David22]

Thanks, I'm in Ireland. Both caps have different resistance does this not matter?