1998 225 OX66 SWSII High Idle

[nicswet7]

Hi - hoping someone here maybe able to help. I have twin 225 OX66 and the one motor is idling at 1900-2000 rpms on start up. It doesn’t come down at all after warming up but stays at that rev range.

I’ve just changed the low pressure fuel pumps, fuel filters and cleaned out the o2 sensor. I haven’t touched the electronic fuel pump or anything there.

I’ve read the thermostats and temp sensors can cause issues but wondering if the Rev range at nearer 2000 is too high for this.

I've checked throttle linkages, idle adjustment etc and all is in order there

If anyone could tell me where to look or what to test that would be much appreciated.

many thanks

Nic

[rodbolt17]

double check you throttle adjustments. then make sure the thermosensor is working,there is only one BTW.
afterthat place the diagnostic test lamp on it.
any sensor failure other than O2 will cause ign timing to lock at a base of 7*BTDC and cause a high idle.

[nicswet7]

Thanks for the reply. Spent some time on it this morning and found a small leak on the fuel line between fuel pump and injector rail. Replaced the hose and it’s sorted it.

[99yam40]

I would think that being on the pressure side there would be fuel squirting out, and loosing rail pressure, not sure how that would cause a high idle

[nicswet7]

There was fuel squirting out you’re right. It wasn’t happening yesterday. The fuel line had perished and the internal separated from the outer layer. As soon as I changed it the idle came down. I wasn’t expecting it to fix it but it did

[TownsendsFJR1300]

There was fuel squirting out you’re right. It wasn’t happening yesterday. The fuel line had perished and the internal separated from the outer layer. As soon as I changed it the idle came down. I wasn’t expecting it to fix it but it did

I never heard of that fix either. Perhaps leaning out and raising the idle?

[rejesterd]

Maybe the fuel was squirting on a sensor. Weird one.