Hot start issues

[percytheace]

Hi all, I've been having issues with my 1978 special for awhile now. The main issue I've been having is after the bike has warmed up, if it dies for any reason it will not start again till it's cooled down.

It's a kick only bike as a few years back I swapped in the MikesXS PMA charging system and put a capacitor in place of a battery. It also has 34mm Mikuni slide carbs rather than the stock ones. Otherwise the bike is stock.

From everything I've read and what troubleshooting I've been able to do I've narrowed it down to being something in the ignition system. I've swapped the plugs for a colder plug, I don't remember the NGK part number but when I get a chance this evening I'll go check. I did some Ohm readings on the ignition coil primary windings and they read at 4 ohms, which I believe is within spec. I also checked my point gap and got that adjusted to .4mm, although when adjusting I noticed that the breaker point cam does have some side to side play, I didn't know if there was an allowable amount of play.

Any pointers anyone can give me Id greatly appreciate as besides the breaker cam having play I'm at a loss.

 

[Signal]

A couple of thoughts.
Do you have loops in the fuel line to the carb sort of down then up, I am thinking of airlocks.
Have you tried using a known good battery instead of the capacitor.

 

[Its been a long time]

Myself, I've given up on points ignition systems. The quality of aftermarket (typically Chinese) points and condensers has never been lower. OEM stuff is available but stupid expensive.

 

[percytheace]

A couple of thoughts.
Do you have loops in the fuel line to the carb sort of down then up, I am thinking of airlocks.
Have you tried using a known good battery instead of the capacitor.

No loops in the fuel line, it comes out of the petcock and pretty much straight down into the carb. I have not tried a battery, I can test that this weekend.

 

[JOHNDADDY]

Check your coils again when hot?
Ehh could be.

 

[percytheace]

Check your coils again when hot?
Ehh could be.

I did, still shows around 4 ohms. So in theory they’re testing fine.