I thought I'd post this to get your opinion.
I run twin F250's (model TXR's, 2006). They are just over 2,400 hours now.
One of them was noticeably vibrating at idle and low speed (under 1,000 RPM's).
Up at cruising speed (4,400 RPM's) I couldn't notice any vibration and the engines always ran great at this speed.
I phoned my Yamaha Mechanic (who moved out of the area) as to what could be causing the vibration.
He felt it was related to fuel delivery or spark Vs. my thinking of a slightly bent prop or driveshaft since I ran over a large ocean Sunfish a while back.
So I went about the following:
1. Changed fuel filters (big Blue 10micron ones) & Checked fuel for water. Not a drop in a clear container. And red ring on filter under the hood was fine.
2. Swapped the coils. 6 from the smooth engine were swapped with the 6 on the vibrating engine.
3. Installed new Fuel Injectors (previous ones had 964 hours on them).
The above 3 seemed to have no effect. Vibration still present.
Then I installed new spark plugs being careful to gap them correctly (1.0mm) and torque them (18-20#).
The plugs only had 230 hours on them but this fixed my vibration problem. Now both engines idle smooth.
I have always gotten close to 400 hours on my spark plugs and the ones with 230 hours all looked fine to me.
I measured the gap on the plugs I removed and a few of them had a gap of 1.1mm Vs. 1.0mm. All looked uniformly okay.
No idea why or how a spark plug could suddenly go bad on me.
Have you ever heard of this? Thanks...
I run twin F250's (model TXR's, 2006). They are just over 2,400 hours now.
One of them was noticeably vibrating at idle and low speed (under 1,000 RPM's).
Up at cruising speed (4,400 RPM's) I couldn't notice any vibration and the engines always ran great at this speed.
I phoned my Yamaha Mechanic (who moved out of the area) as to what could be causing the vibration.
He felt it was related to fuel delivery or spark Vs. my thinking of a slightly bent prop or driveshaft since I ran over a large ocean Sunfish a while back.
So I went about the following:
1. Changed fuel filters (big Blue 10micron ones) & Checked fuel for water. Not a drop in a clear container. And red ring on filter under the hood was fine.
2. Swapped the coils. 6 from the smooth engine were swapped with the 6 on the vibrating engine.
3. Installed new Fuel Injectors (previous ones had 964 hours on them).
The above 3 seemed to have no effect. Vibration still present.
Then I installed new spark plugs being careful to gap them correctly (1.0mm) and torque them (18-20#).
The plugs only had 230 hours on them but this fixed my vibration problem. Now both engines idle smooth.
I have always gotten close to 400 hours on my spark plugs and the ones with 230 hours all looked fine to me.
I measured the gap on the plugs I removed and a few of them had a gap of 1.1mm Vs. 1.0mm. All looked uniformly okay.
No idea why or how a spark plug could suddenly go bad on me.
Have you ever heard of this? Thanks...
Comment