need parts help

[boscoe99]

Thanks Boscoe and 99yam!

I'll sugest you remedy to my friend and we'll see what he decide.

I know a guy with a bike workshop/garage that have specific drills, diferent sizes to rejet jets and that maybe an option (a piece of metal wire in not an option)

There is a site/store in the US selling original Keihin jets for a fraction of the price that yamaha sell them) Just 4 or 8 jets may keep our costums far from the package

Slow Jet F25 #50 F40 #38
Main Jet F25 #112 F40 #95

I used jets from the F25LA. Slightly smaller than the jets you mention.

[almetelo]

According parts manual the aplicable models are:

F25MHC. F25AMH, F25AM
F25EHC
F25ERC
F25TRC, F25AET
F25AEHT

Must be almost the same.

but this manual parts is for 2004 model
maybe newer models may be slightly diferent

(dont have a access to newer models manuals)

[boscoe99]

Here is another source

Keihin carburetor jets and parts main jet slow air pilot kit

Parts catalog for US models can be seen at yamahaoutboards.com or here at boats.net

[almetelo]

yes, that was the site I was talking about

[99yam40]

Might seem that way but in the case of the F25 the one carburetor is feeding two cylinders. In the case of the F40 there is one carburetor per cylinder for three cylinders.

Sorry did not realize they did not have individual carbs for each cylinder.

Still I was thinking I had read about the shape of the orifice affecting the flow of liquid fuel.
Just thinking about the drilling may not be as good as factory jet.

Maybe that was non liquid gases, just cannot remember right off hand.

The hard wire mention was just that there was a recommendation to not use them while cleaning carbs as it can damage the jet, My thoughts were they could change the shape not just the size, but who knows for sure.

Sure would be nice to find some reference to jet numbers and hole size on Yamaha's

After doing some searching, it is best not to use a drill.

Here is a post I found on jets that is interesting to say the least, and seem like my memory was from when I was an auto tech back in the 70's. Or working on some bikes

"Some jets are actually marked in relation to their size, others have arbitrarily selected numbers related to their flow in proportion to others. I'm told Mikuni does it both ways for different types of jets. I do know that Holley jet numbers do not relate to their diameter, there are several sets with different numbers that have the same minor diameter, the different flow is caused by the entry and exit to the minor diameter.

jets don't wear out, unless someone has been poking wires or tools through them."