engine miss at 2,000 rpm to ?

[HOZ]

I have had a 98 Tourer since 98 and it has 157,000 miles on it, still runs strong no problems to speak of. Just bought a 99 I/S a month ago and it has 45,700 on it. Stock as far as I know. I have noticed a miss above about 2,000 rpm, if in town in say 2nd or 3rd gear hold steady at 2,000 about or above it has a miss, not consistent though, not like 1 cylinder only. Also happens on the freeway in 5th gear at 60 and 70 mph (2,500 to 3,500 rpm) haven't done any exploring yet as to the problem. Thinking vac. leak so far. Any thoughts. TIA

[Ricky-D]

Maybe a little more definitive description of what you say is a "miss"

I'm not picking at what you are saying but right now it could be electrical or carburetion.

What have you already tried to get to the bottom of the problem?

***

[HOZ]

A slight poping, not back fire. Nothing yet as far as work, just thinking so far. I'm on vacation and lazy. I'm thinking vac. lines need to be changed maybe. That's where I'll start anyway. As you are driving down the road you can hear the engine stutter ever so slightly and not sure how many cylinders are effected. Maybe just one. Hard to tell. Other than that starts and runs good, except power does seem to be down compaired to my tourer. But my tourer has aftermarket exhaust and an I/S ICM and about 4.5 to 5 deg trigger wheel. So I guess its hard to compair the 2 bikes as far as power. Sorry for the general description of the problem without hard facts. Just starting this venture.

[Ricky-D]

I understand what you are saying.

Mine has been doing the same exact thing for a couple of years now and it's an aggravating and annoying thing, but it doesn't seem to be affecting anything else.

I've tried some little things to see if there is any change but nothing so far. It kinda comes and goes. I've probably put 30k to 40k miles on it like it is and it's still there.

My take is that it's a loafing cylinder. Not contribution 100% in line with the other five cylinders.

I gutted the exhaust a few years back and I think maybe that's part of the cause. I've synchronized but that doesn't get it either.

If I had to bet on the cause I would say it is a bad fuel level in a float bowl but the floats are non adjustable.

I can't even identify the bank it is on, much less the cylinder. If I could identify the bank and the cylinder it would really help.

Everything is fine with the motor,it runs strong with a 6 degree wheel and I'm getting 40mpg or better.

One thing I found to help was going to non ethanol enriched gasoline. It stopped a lot of the popping but the loafing on the highway is still there.

It hasn't changed at all so I'll just keep riding until it either gets worse or the motor quits all together.

***

[Farther]

One thing I found to help was going to non ethanol enriched gasoline.

  Where do you live that you can get non ethanol fuels?

[BudMan]

More stations here in Oklahoma have 100% gas than have blends.  That was not the case earlier this year, but nost places with blended fuel have gone back to pure gas. 

[John U.]

I guess the corn lobby is not as strong in Oklahoma 

[HOZ]

NOT what I wanted to hear, Ricky-D. Oh-well guess I will be on a quest this winter to see if I can find the problem. Drives me nuts. So bad we took the car on a 3 day trip this week. Now thats bad. Just can't stand that miss. My Tourer runs so smooth and has for so long I guess I'm spoiled. Time will tell.

[dreamaker]

I have the similar issue. Valks have a hum to them and mine changes. It sounds to me like a slight flutter not a full blowen miss, I can take off and it sounds great and then stop at a light and then hear the flutter. Then the next light it may go away. I tried everything I could think of, changing and replacing, but it's there and not there a real hair puller. The bike starts with no problem and has never died, but that flutter come and gone drives me nuts.

Dan

[Ricky-D]

Dan, I've got to say you are more "right on" in describing it as a flutter. Annoying but non-affecting the running.

Synchronizing helped a bit, so does non-ethanol gasoline.

I'll add more information to my list so where I am located will be displayed.

 Farther: there's stations all over the USA that vend non-ethanol gasoline. Contacting the gasoline distributors will reveal which ones distribute that variety and they will tell you which stations vend same. Mine here in SC is a local private pantry type that's part of a family run operation that also distribute the gasoline. A lot of stations also have signs that state "non-ethanol sold here"  Just have to hunt them down.

Hoz: I'd suggest to not do anything to change what you have. Maintenance is one thing but to alter any settings might put you down an undesirable pathway that may be difficult to retrace.

***

[98valk]

things to check.
u using stock petcock, the vacuum diaphragm wears out near the center from the constant movement which is extreme during shifting. Most will need to use a magifying glass or eye piece to see this. The diaphragm is a piece of material that is rubber coated, the coating wears away. Rebuild it and install a snubber in the vacuum line which prevent the excessive movement.
the other thing could be ignition. The stock plug wires are solid core and have a resistor installed into the plug end with a plug that screws in. if this comes loose an intermittent condition like is discribed could be the cause.
I use moroso wires and requires that the stock plugs have screw caps installed on the threaded part of the plug. somtimes they come loose and I get intermittent misses.