Cold (Hard) Starting 2 Strokes

[Aceman]

I have a new 50 hp 2 stroke on my flats boat. Hard to start cold. Pump up the primer ball 5 or 6 times then it takes several attempts to start. Really hate grinding the started. Fast idle lever doesn't help. Pushing key switch does nothing. Understand it has an automatic choke (I miss the toggle switch choke control on my old one).
Once started and warmed up starts immediately every time.

Posted this issue on inshore fishing forum and got 5 or 6 others with same issue on newer 2 strokes.

What can be done to make the things start easier when cold ?

[jb123]

ensure when pusinng key that butterflys are closing, not sure about your model but does it also have the manual pull choke on the motor?

[Aceman]

Sure wish it had a manual choke or even the old toggle switch choke on the control box like my old 50 hp - its got nothing.

Fast idle lever only stalls it when cold.

Pushing in on the key during cranking does nothing.

[Ken]

Ace,
I'm pretty sure your motor has the "prime-start" feature for cold starts - item #34 in this diagram:

http://www.boats.net/yamaha/partsyst...mponent=395862

This prime start assy is just a solenoid and pump that gets a 12 volt command when the temp is low enough (and you're right - pushing in the ignition switch does nothing). You can monitor this 12 signal when the motor is cold and ignition to start position. If the 12 volt signal is there, then the solenoid/pump is bad.
But if your motor is new, then it should still be under warranty - let the dealer fix it.
Good luck [img]smile.gif[/img] ,
Ken K

Ace,
I'm pretty sure your motor has the "prime-start" feature for cold starts - item #34 in this diagram:

http://www.boats.net/yamaha/partsyst...mponent=395862

This prime start assy is just a solenoid and pump that gets a 12 volt command when the temp is low enough (and you're right - pushing in the ignition switch does nothing). You can monitor this 12 signal when the motor is cold and ignition to start position. If the 12 volt signal is there, then the solenoid/pump is bad.
But if your motor is new, then it should still be under warranty - let the dealer fix it.
Good luck [img]smile.gif[/img] ,
Ken K

Hey Ken, sorry to bring this thread back from the dead, I'm having the same problem with my '05 90hp 2-stroke. The boat originally had a 4-stroke, then a 2-stroke was dropped in with the original wiring harness, so some of it was hacked up. The question is what wire does the start prime assy solenoid plumb into? is it the similar coloured blue wire coming from the main harness? The reason I'm asking is that I'm aware that it should not come on when the key is pushed in, yet the blue wire in the harness is feeding a 12v signal when it's pushed in.

[dorf]

I've got a '06 50 TLR, similiar problem.--with, Prime Start System---

What I've done........
Removed the boat mounted anti-siphon valve(helped somewhat).
Replaced all of the fuel lines and the quick disconnect to the engine.
Re-Routed the fuel lines.
Replaced the 10 micron Yamaha fuel filter
Verified the ignition timing
Verified the carburetor sychronizing
Checked compression(115 all three)
Re-Adjusted Idle several times


Sometimes it starts OK.... High RPM 1500, then after a little while drops to 850. Seems like there is a "fine gap" in idle settings. Too high and it bangs/grinds going into gear. Too low and it stalls out.

-PUSH the remote control throttle arm IN, to engage the "Free Accelerator" function and you can catch the "Stumble" and bring up the RPM. Then bring back to idle position.

Adjust you idle alittle at a time...

I purchased Yamaha 2005 factory manual(not avail for 2006) and a Clymer Manual-('99-2002), which is a Good book, seems better than the factory manual-it has better descriptions etc.