[John Holbrook]

I purchased a 2005 an 400 in August, rode it home (25 miles) and all seemed fine. Had surgery and was unable to ride until yesterday.
When I went for a much anticipated ride, I noticed that if I accelerate, then back off the throttle, and immediately accelerate again, there is a momentary stumble or hesitation for about one second. After that all is fine. Is this a quirk that is common to Burgmans?
I thought maybe it was the rollers and belt combination needing a second to engage completely.
Not sure how to explain what is going on. If I accelerate, then back off, and wait a second or two, then there is no stumble or hesitation.
I did adjust the valves and change spark plug during my downtime. Could I have misadjusted something? The exhaust valve had a clearance of .002 and I set it at the max allowed.
It is a great bike and I love riding it!
thanks!
John

 

[cliffyk]

At what vehicle speeds is this occurring?

 

[John Holbrook]

Happens 20- 40 mph

 

[cliffyk]

What you describe is sort of "normal" for the 400 at those speeds, though the way you describe it sounds a bit worse than it should be--without actually riding it it's difficult to say.

One thing is to learn to not roll on or off the throttle aggressively. If you can find someone with experience with a bigger bore "rubber band" drive scooter (another Burgman, or a Majesty or Kymco) let them ride it and see how it feels to them.

You may also want to open up the CVT and disassemble/clean the variator, also check the clutch and belt width, etc...

 

[John Holbrook]

Thanks!

 

[Mel46]

I have had mine for about 15 months now and I have noticed that it hesitates when trying to accelerate to full throttle and when backing off and then applying the throttle again. In fact, I get a squealing from the belt and then it catches. So, maybe that is normal.

 

[cliffyk]

I must admit being curious as to why this--hard acceleration, back off, then accelerate again--is being done? In 50+ years of driving cars, trucks and bikes, it has never been something I have needed, or even wanted, to do routinely...

 

[John Holbrook]

must admit being curious as to why this--hard acceleration, back off, then accelerate again--is being done? In 50+ years of driving cars, trucks and bikes, it has never been something I have needed, or even wanted, to do routinely...
__________________
- I was just having fun. Accelerating, slowing, accelerating. It wasn't hard accelerating, just on and off the throttle! The road was twisty, and there was no traffic ..... John!

 

[Mel46]

I sometimes have to do that maneuver when idiots cut me off just when I accelerate, and then I have to go around them before they hit me! The traffic in Atlanta has become like a little New York City in the last 20 years. Some of these drivers do not hesitate to cut through a grocery store parking lot at full speed, with shoppers jumping out of their way! It has become a crazy place to drive now, especially on a scooter or bike.

 

[Mel46]

By the way, Seafoam helps with that problem.

 

[cliffyk]

I would not use Seafoam in anything but a 1950 to 1970 marine engine that was run cold and/or improperly stored over the winter. That's what it was originally designed to "fix", and why it's called "Sea" foam.

In 55+ years, as I have not had a cold running or improperly stored marine engine, I have never used it or even felt a need to use it...

 

[Mel46]

Well my Burgman sat for 6 years before I bought it, so it was pretty gunked up even after the service tech flushed it completely. Using the Seafoam I have been able to get it to run a lot better. It is slowly cleaning out the injectors and garbage in the gas tank. Others swear by it and I agree.

 

[cliffyk]

Well my Burgman sat for 6 years before I bought it, so it was pretty gunked up even after the service tech flushed it completely. Using the Seafoam I have been able to get it to run a lot better. It is slowly cleaning out the injectors and garbage in the gas tank. Others swear by it and I agree.

That's exactly the sort of engine conditions they made it for...

 

[John Holbrook]

I found the culprit (I think). I rechecked valve clearances to make sure I had them right. While taking it apart to get to the valves, I realized the spark plug wasn't tightened. It was loose enough that i could turn it with my fingers. I tightened it, checked everything carefully and went for a ride. Much better! Still hesitates some, but not much.
I usually double check everything since the time I left rags stuffed into the carbs of a Cavalcade and went for a test ride! Got about half mile and she came to a stop. Is hard to push an 800 pound behemoth!