225 ox66 surging

[venator66]

I have a 2001 yamaha 225 ox66. When I am trolling it will stay at whatever rpms I want until I try to go to 1900 rpms. Once I get there, it starts fluctuating between 1900 and 2400. It will smooth out again if I bump up to about 2300 rpms. It just wont hold between 1900 and 2300 rpms. Anyone have any thoughts or experience with this problem? I have no other problems at any other rpm range, it runs smooth and idles fine.

 

[cousinabe]

Re: 225 ox66 surging

clogged vst filter.

check your fuel rail pressure at problem rpms.

 

[venator66]

Re: 225 ox66 surging

Thanks, I'll start there.

 

[bernieb]

Re: 225 ox66 surging

I'm going to stick my neck out and say that the jack-up in rpm's is perfectly normal around the rpm range your speaking of. I have a 2001 250 0x66 and it does the same thing. I'm remembering running on 4cyl, then kicks in the other two..............but check on to be sure.

 

[rodbolt]

Re: 225 ox66 surging

kinda what bernib says.
about 1800 RPM that engine is trying to go from 4cyl operation to 6 cylinder operation.
couple that with that kind of RPM is very hard on that motor why would anyone in there right mind try to do it for long.
hull cannot plane at that RPM and that poor large bore 6 is lugging like mad.

 

[venator66]

Re: 225 ox66 surging

Thanks for the additional information. That is why I asked the question. I am relieved to find out this may be normal and now I know. I usually troll when fishing and sometimes I need the little extra speed to get the lures to track in various sea conditions, but now that I am aware of the strain on the motor, I'll adjust differently.
I don't beat on the motor, it's on a 27 Rambo with a narrow beam and doesn't start to plow until about 2200 rpm. Does this indicate it might be propped wrong? WOT is 5000 rpm.