F3 Vibration "Work-Around"

[Slagiatt]

This is one of two threads I'll be writing related to my recent trip from Indiana to Arizona and back (3,565 miles) on my F3S. This thread relates to how I dealt with the 4K rpm vibrations.

For those who don't know it yet, the F3 can turn into a vibrator anywhere between 60-80 mph in 5th or 6th gear. You really feel it in the grips, pegs, and seat. It is not a constant phenomenon and the speeds that cause vibration seem almost random. It is so rough that I'm having a post-trip oil change done next week and I'm going to have them check the old oil very carefully for any evidence of excessive wear.

Anyway, here is my experience and what I discovered.

At the beginning of the trip this was a MAJOR annoyance--our F3 version of the '13 RT's heat issues, I thought. I wondered whether the engine was going to shake itself apart. And yes, I'm convinced this is the engine, not the belt, for reasons that will come clear below.

The work-around I discovered (although it seems bizarre) is as follows: Suppose you want to set your cruise at 70 mph and when you do, the spyder is vibrating. To remove the vibration, simply throttle up quickly a few mph (say to 72 or 73) and release the throttle and let the cruise take over again...smooth! No vibration at all. This method worked pretty much every time at any speed when the spyder was vibrating, through the entire range of 60-80 mph.

The reason I say this is the engine (and not the belt) is that sometimes, when riding at, say, 70 mph (cruise on) and coming to an uphill grade, the engine would labor and begin the vibration. Again, a quick acceleration and release of the throttle (even when still pulling the grade) removed the vibration. Once running smoothly, it continued to do so at that speed without a problem. It just seems like the engine can't get itself to consistently run smooth around the 4,000 rpm range without some nudging or tweaking. Go figure!

Perhaps some good mechanical diagnostician can get in the game here. Regardless, I can't imagine that BRP didn't know about this before the F3 was released. Is it possible they didn't road test at those speeds? With all of the test rides they've had around the country, do they always keep them under 60 mph?

Now, on the up-side, that was the only flaw in an otherwise (in my opinion) near-flawless design of a vehicle. I would call it a just-more-than-minor annoyance, now, that I hope BRP can figure out...soon.

On my other thread (which I'll post soon) describing the trip, I'll talk about other observations, opinions and recommendations I came up with over the time on the road...all good, by the way.

[Tom in NM]

I had my 3k service today and was a little concerned that I might now have the irritating vibration that some have noticed. Nope, still nothing nothing noticeable for me.

I hope this gets resolved for those that do have it.

Tom

[ca8920]

I had mine out yesterday and experienced the same issues. If I sped up to 75mph then dropped back down to 70mph the vibration seemed to vanish. If however I slowed to 68mph then sped back up to 70mph the vibration returned.

[Machinegunner]

I noticed the vibrations too. It also went away with the slight speed increase and then release. It appears to me to be harmonics in the belt, or else we could not over come the problem with slight adjustments in speed. A balance problem in the motor would not go away so easily.

[mikedoucette66]

I think these long belts need a belt tensioner!!!