2005 Yamaha 225 four stroke max rpm 5000

[razz]

I can only get 5000 rpm out of my 225 this year. Dont know if its a fuel problem our what.. I have changed plugs and oil this year fuel filter at the end of last year maybe two trips on it. Stored in side for about a month and back out fishing due to no winter ice. Starts fine and runs smooth just no top end. Lost 10 mph and about 900 rpm.

 

[rodbolt]

Re: 2005 Yamaha 225 four stroke max rpm 5000

what is the normal top RPM.

 

[razz]

Re: 2005 Yamaha 225 four stroke max rpm 5000

5900-6000 is what I was getting out of it ..

 

[razz]

Re: 2005 Yamaha 225 four stroke max rpm 5000

ok I changed the fuel filters (all three and vent filter) fuel pressure is good ..spark plugs again . checked all cylinders for spark..ok good compression on all cylinders.. This thing starts great runs smooth but does not have power like it should have.. I lost ten mph and about 1000 rpm ...what else could be wrong???? the only other thing I did to it was change the oil.. does it have an oil level safety that would limit the output?? I am running it about half way up the stick..I even drained the tanks and put rec fuel (no eth) in it...please any advice would be greatly appreciated

 

[razz]

Re: 2005 Yamaha 225 four stroke max rpm 5000

after more diag. fuel pressure is 40-45 lbs.. i have found that it has a miss (ignition) at any rpm on all cylinders . kinda intermittent??? any ideas?? hmmmmm......

 

[rodbolt]

Re: 2005 Yamaha 225 four stroke max rpm 5000

check secondary firing voltage and check the injector screens.

 

[razz]

Re: 2005 Yamaha 225 four stroke max rpm 5000

check secondary firing voltage and check the injector screens.

How would I go about that (checking secondary firing voltage) what should it be??
I put a timing light on the wires and I see a intermitten loss of spark it dosent matter what cylinder I put it on...when I changed fuel filters the only one that had any dirt/debri was the second filter after the first pump befor the vst tank.

 

[rodbolt]

Re: 2005 Yamaha 225 four stroke max rpm 5000

buy a Kv tester to test secondary voltage, a peak reading meter or a digital meter and a DVA adapter to check coil primary voltage.
not a real good way to test the port bank injectors.
when I have the VST off for service I swap out the port bank injectors with reworked ones.
check the fuel rail pressure at the problem RPM.