Cold start problems.

Sgt Robuck 5

I recently had a topend rebuild done by me on my bike all seemed to be going well when i noticed the bike was having problems starting. The problem only seems to happen when the bike is cold, it does start after around 25 tries. i performed a compression test and the reading was around 125 psi which seems to be good. I did replace the sparkplug and the bike seemed to start within 3 kicks for a few days. but now the problem is back and worse.

Calum

The bike struggles with choke?

oldman

What was the plug like when you checked compression?

Sgt Robuck 5

@calum Yeah. it's a bit on and off. was playing with the electrics disconnected the battery and the bike started-although sounded like a dying horse- then I reconnected it and seemed fine and then wouldn't start again when i turnt it off and tried to kick again. Then I cleaned up the battery terminals/contacts, Seems fine for now tho.

Sgt Robuck 5

@oldman golden brown, Seemed fine enough. Did replace the sparkplug when it happened and solved the problem for like 3 days however.

oldman

Thought the plug might be fouling but obviously not, had problems with the loom on both 88 and 89 bikes, always the earth. Doesn't sound like that's your problem though, if you have a multimeter might be worth checking. Is the spark consistent when checked?I am sure you have ruled out many of my daft suggestions but curious to know, information is power!
On the 89 bike following rebuild ran fine to start with then deteriorated rapidly, spark plug fouling something awful, had put in strawberry 2 stroke oil (don't ask) and when I checked the gearbox oil had a strong whiff of summer fruit about it. Crankcase seal blown, sorted that and it's been fine since.
The only other suspect would be fuel related, can normally smell that though if you are kicking over repeatedly at the exhaust. Whip the plug out when it won't start and see if it's wet with fuel, sorry if I am teaching you to suck eggs btw.!

Sgt Robuck 5

@oldman Any help is amazing bro! will see how it is tomorrow and go over some of this stuff