Honda 40hp problem

[Mello-Yello]

Hey gang,
A co-worker is having problems with his 40hp Honda outboard...3 cylinder, carburetor fuel system. It idles fine, but when he gets on it, it starts to take off then fall on it's face. He was told initially that this was due to condensation in his engine block, thus increasing the oil level (perhaps some kind of rev-limiter?)..He changed the oil, still has the problem. Next, he was told the thermostat was likely stuck open due to corrosion and the engine wasn't able to warm up...he replaced the thermostat, still has the same problem. He's checked his plugs, all look fine, and installed a water separator...still no luck. I've advised him to add a fuel stabilizer as he may have had some old/bad gas in his tank prior to filling it (for some reason people think that if you add new gas to old gas, it makes it all new gas).

Does anyone having a similar motor ever had this problem? And if so, what was the culprit?


Thanks in advance,

M-Y

Check the fuel filter or he might have a pluged jet in the carb.

[corrirod]

M-Y, does it do it all the time or are there times when it runs fine? If so, and even if not, I'd start checking the electrical system. I just spent $300 for the shop to locate a worn wire. It was rubbing on the flywheel and creating an intermitent spark to the coil. Same symptoms as your talking about except occasionally it would run fine.

[Orca]

Could also be the fuel line primer bulb, these have been known to stick and restrict fuel flow.

I would also suspect the carb(s), possibly some varnish or crud/corrosion blocking the main jets or some crossover jets depending on carb design.

[ 06-04-2003, 08:47 PM: Message edited by: Orca ]