Hard to start cold

[Mac3]

Hi all,
have a 98 Johnson 150 Ficht, it has developed a cold start problem. Starts ok, idles fine, but when you put it into gear it dies. After about 10 minutes of cranking with misfires or no fire at all it suddenly bursts into life and doesn't miss a beat for the day, can be stopped and restarted anytime. Fuel bulb is firm, plugs about 75 hours old. I gave the TP switch a squirt of WD40 but that didn't do much. It is hard to diagnose when it won't do it again until the next outing.
Thanks in advance,
David

 

[MikDee]

IMO, it maybe a crazy idea, but check your thermostat! If it is stuck open, or a delay in opening, the engine maybe running on the cold side for too long. Taking to long to warm up!

 

[boobie]

Try replacing the spark plugs in it and index them properly.