40hp 4-stroke model number question?

[shane2mc]

Hi y'all. I'm looking for a little help from someone knowledgeable about Yamahas. I recently bought a boat with a 2003 Yamaha 40hp 4-stroke on it. It's been sitting a lot, and the motor runs OK until it's in gear on the water. Then it bogs down. Not enough power to plane out. Sounds like a common issue with these 40s. I'm gonna put bigger jets on it (F25 jets). While I have it apart, I'll put a carb kit in it. Looking at the parts store, there are 6 different model numbers that begin with F. Does F mean Four Stroke? I've looked at the title as well as all over the motor, and I can't find a model number anywhere. How do I figure out what my model number is, in case it matters for some parts? The carbs are all the same, but are some other parts different between all these model numbers?

[99yam40]

model # ,serial #, and date of manufacture is usually on stickers on Motor mounting brackets.
and yes the F means 4 stroke

Have you clicked on the red Yamaha psrts on top of these pages?
gives good info and show parts once yu pick you motor

[shane2mc]

Yes sir. I went to Boats.net. That's where I am seeing all the various model numbers for the 40. I'll look again on the mounting brackets to see if I can find my model #.

[boscoe99]

Did the motor come from a Yamaha USA dealer? If so, you can go to the Yamaha USA website and open the parts catalog. Insert the ID of your motor, press the go key and it will take you directly to the parts book for your specific ship serial.

[shane2mc]

Awesome. Thanks, boscoe.