View Full Version : Force 120 not wanting to shift

07-03-2009, 01:50 AM
"I have a Force 120hp that I just recently changed the impeler because it was overheating on me. This is my first boat and I only had it about 3 weeks. Now my problem is that it cuts out as soon as I go from neutral to forward or reverse. Motor runs great when I can get it to shift, but most of the times I can try for at least 20 times and it won't stay running. Can someone explain what's wrong? Thank you."

07-03-2009, 10:56 AM
"Yep, the carbs are clogged. Not enough gas is getting through the low speed jets to keep the motor running under load (when you put it in gear).

The idle speed normally drops by 100-200 rpms when you shift, so enough gas is getting through to let it idle in neutral, but once there is a little bit of strain on it, it gags out from lack of fuel.

That is a typical condition on a motor that has been sitting for a few months or more and was not properly prepped for storage.

Unfortunately, now, the only solution is to remove the carbs, disassemble them and clean them thoroughly - there is no magic additive in a can that you can put in the gas to get them cleaned out....."

07-03-2009, 11:36 PM
"Graham is right, but -- you may be idling to slow. Your idle in gear should be 700, or so. If your idle is that before you put it in gear, she will die."

07-03-2009, 11:57 PM
"I will have to check that, thank you."

07-07-2009, 12:24 PM
"I've had the same problem, so I'm going to check these same things on my motor. I have one more question though - how do you check your idle in gear? Using the tachometer or is there another tool?

I didn't mean to hijack the thread. I've learned why my motor is behaving the way it does, and I just needed a bit more info.


07-07-2009, 04:07 PM
"To be honest, I'm not sure. I will let you know when I find out. I'm having someone help me with this matter. Sorry I couldn't been more helpful."