78 6hp- hard start when warm

Moosebreath94

Recruit
Joined
Feb 1, 2011
Messages
4
I've had this motor for 12 years, had head gasket replaced once. Added a flywheel generator when I first got it (hard on electronics!)

The motor starts fine when cold, but is hard starting or no start when hot/warm. Sometimes I just have to let it cool for 15-30 min, then it starts fine.

I will clean the carb this winter. I want to replace ignition parts. When I start looking at coils & wires, rectifier and capacitor, the price really starts to add up. Are there any of these ignition parts that have a history of opening up when warm?

Jim Herbert
MN Sailing Alliance
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: 78 6hp- hard start when warm

No need to guess -- warm it up, pull a plug, reattach it to the boot, hold against the head & look for a spark while somebody pulls the rope.

Worn float valves can let a little fuel seep past when you stop, flooding the motor, makes for a difficult warm start. If this is the case, a few pulls with the throttle in the cold start position usually helps.
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,446
Re: 78 6hp- hard start when warm

I think the cd ignition modules usually fail while running and get warmed up, but either way, when it won't start, check spark immediately and if it's good and strong, carb flooding could be a possibility. I'm assuming the waterpump is cooling fine and water's coming out the exhaust port...

If you lose both sparks at same time, it's probably the cd box. Also could be the 'trigger', or the charge coil under flywheel, but less commonly. You can check those with a regular muliti-meter (w/o pulling the flywheel, I believe).. Search this forum for that procedure. Good luck! You and check part numbers/schematic here: http://epc.brp.com/SiteMods/BRP_Public/BRP_Public_Login.aspx?ReturnUrl=/Index.aspx
 

raczekp1

Lieutenant
Joined
Mar 30, 2010
Messages
1,327
Re: 78 6hp- hard start when warm

hi.
i think there can be low compresion problem when engin warms caused by wraped head.
i would check compresion when engin warms up and its dificult to start.
 
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