225 hp has 1ooo rpm less wot than other

[dtroise@bellsouth.net]

Hello
I have twin 225 hp yamis and one motor has 1000 rpm less at wot than its twin, the prop is not slipping and i am wondering if this is a cdi problem

thankyou

[99yam40]

Probably not

Did you pick up your manual yet and make sure everything was adjusted properly?

Why is it no one wants to post model #s anymore?

Start with the basics compression, spark, timing, and then fuel system.
Fuel pressure/vacuum should tell if filters or other restrictions are a problem
Make sure you have the same prop on both motors and they are the right ones for your load ( boat set up)

[rodbolt17]

over the years the 225 has been made in both EFI two stroke,carbed two stroke in both 2.6 and 3.1L as well as EFI 4 stroke.
all take slightly different approach to testing.
if it helps, most since 1995 are painted silver gray.

[dtroise@bellsouth.net]

Sorry about the model # it is a 1995 225 carb v x 6- 76 degree 3.1 txrt, yes both props are new and they are the same,left and right.the hub kits are new also, i checked the spark with a spark tester at idle and all cylinders have spark but i wasn't sure if the spark breaks down under load, i changed fuel hoses from engine to tank recently and new plugs and filters, i did test the fuel pumps as i thought they could be the problem but they do not suck air or leak albeit they are probably the originals and I just changed the other engines, i regularly de carb with sea foam and always run stabil, I did order the original manual and it will be here soon. Is there a way to test the cdi or coils to see if they work at idle but possibly break down under load?

Thank you

Donald Troise

[99yam40]

16 year old pumps?
probably need to change them.
Seems I just read someone the other day fought something like this and his was old fuel pumps even though they were not leaking

Hopefully Rodbolt17 will be back to give you some help, he does this stuff for a living and is good at it

[dtroise@bellsouth.net]

I replied under a new post, sorry about that

[dtroise@bellsouth.net]

Thanks that is the cheapest route but it doesn't sound like fuel problem when running

[99yam40]

I would think monitoring the fuel pressures would tell you if it was fuel or not.

A inductive timing light should show if you are getting spark to individual plugs at problem RPM by moving it to different plug wires.
Then there is monitoring peak voltages to and out of CDI at problem RPM should show something

[dtroise@bellsouth.net]

I will do the fuel pressure test however the other test will be difficult while the boat is at wot as It is in the water w/o a trailer and it seems that I would need it in a test tank

Thanks

[rodbolt17]

you will either need a test wheel or do it in the water under normal load.
could be fuel pumps,make sure the electric pump is operational,make sure the cylinder head temps are normal,above at least 113*F under load.
make sure TPS voltage is correct,make sure throttle opening is correct.
\