2001 30elrz carb issues?

[FlCastnblast]

Hey all,
New to posting but Ive lurked around for a couple years siphoning off info from time to time.

My dilemma brings me here as a registered user now.

I picked up a 2001 yamaha 30elrz a few months back and it always ran a little funky. Never could quite get it to top rpms and it was finicky. The primer ball would never get completely solid. The idle was rough and I would have to lightly squeeze the primer to to get it to pick up towards wot. Its on a lowe 1652 and i would regularly get 27mph out of it although it hesitated to get on plane, occasionally it would pop up with in 3 or 4 seconds. I know its not a prop issue.

Anyways, I rebuilt the carbs with all new components, soaked the carbs in chemdip for a few days, re plumbed the entire fuel system with new hose and a primer ball, replaced the fuel pump diaphram and the fuel filter.
I cleaned everything out well, gave it all a few shots of carb cleaner and compressed air, and put it all back together. I also cleaned out the gas tank and put fresh non ethanol in it. (I only run rec 93) I synced the carbs according to the service manual, which I had done successfully a few times before in my attempts to clean the carbs to solve the problem.

The driveway test was perfect. It idled as smooth as id ever saw and the throttle response was lightning fast.

I took it out the next day for a water test.
It started up perfect, idled perfect. I noted how much more throttle control I had in those lower rpms. It was amazing.
Once I got out of the no wake zone I went for the WOT run and I was shocked. The boat wouldn't even get on plane. 10mph was the highest speed it would get to. Its just a steady bogged down engine.

I just dont understand it. Ive been over it multiple times in my head and have no idea where the issue could lie. I have been out again since, changing the inline fuel filter and checking the fuel lines for vacuum or air leaks.

I am at a loss. I figured the carb rebuild would have made it run better (which in some aspects it did) and not worse.

Any help or direction would be greatly appreciated.

Thanks from Fl

[TownsendsFJR1300]

If the bulb is staying hard now, I'd be checking for spark.

Sounds like a misfire once under load.

A compression test to rule in or out basic engine health wouldn't hurt...


.

[99yam40]

and check timing with a timing light to make sure it is in spec and advancing as it should.
timing does affect power

[FlCastnblast]

Thanks for the prompt responses. I really appreciate the help and direction.
Ive done a compression check just prior to my carb rebuild 135 125 135 and all cylinders have strong blue spark.

I dont have a timing light and I dont have any experience in adjusting or checking the timing.
I assumed since it was running fairly well before that the timing was ok.
Im mechanically inclined. Ive read the service manual description of checking the timing, its somewhat hard to understand as far as technical terms and specific parts.
Any videos that can help me further with that process?

[99yam40]

can up post the instructions you do not understand
maybe someone can explain it

[FlCastnblast]

After taking sometime to go over it again and looking at the diagrams i think ive got it figured out.
i have to get a dial gauge indicator first though.

My gut tells me its not the timing as that shouldnt have changed and it seemed ok before.
Is there anything else it could be?

Perhaps i should take it all apart and put the original parts back in and see if I can restore the original functionality of the engine?

What are the symptoms of a fuel starvation issue?
I did not use oem fuel lines, rather I bought a section of 1/4" inner diameter fuel hose.
Would that possibly be the issue?

[99yam40]

you really need to know if the sparks are hitting at the correct time while the motor is running
My C40 had a problem with timing when I got it 3rd hand and someone had drilled out the main jets.
some auto part stores have tools they will loan out,
maybe a friend has a light,
or find one on line

good compression, good spark at the correct time, and the proper fuel to air ratio are all needed to run properly

too much, or too little fuel will not burn properly

[FlCastnblast]

Ok. i see a harbor freight has the gauge i need. Guess im headed there.

Will report back my findings. May take a day or two.

[99yam40]

a timing light is not a gauge

[FlCastnblast]

Per the service manual to set the timing requires a dial gauge indicator. The pick up timing requires a timing light.
Regardless after this afternoons garage session everything appears to be in time and within spec. After finding tdc and reversing .14" the marks line up with the flywheel and magneto. The advance timing also is spot on and the retard timing is too obviously after following the steps in the service manual.

My attention has turned back to the carbs.

On the top side of the carbs are two additional jets hidden under rubber plugs which are not mentioned on the exploded diagram.
After pulling them out Ive found enough debris (although not that much) in them to warrant another cleaning.

Ive decided to just send them in for an ultrasonic cleaning. If that doesn't solve the problem I'm not sure what else could.

Ive already checked the ignition coil resistance and changed the plugs so I'm not sure there is too much more that can affect the performance that I haven't already checked.

I am certainly still open to suggestions and advice.

Thank you all for the input thus far.