miss firing

[tom203]

Believe it or not I leaned out the airscrews and it cleared up. And all my valve clearances were within spec. Less than 4 thousand original miles on the bike and it shows

I'm very gullible! but you are lucky that PO readjusted the valves after break-in so they are all within spec. Just why did you "rebuild" the carbs at 4k? As others have hinted, a good cleaning would have done the trick- aftermarket rebuild kits tend to be poor quality. Sure you need new o-rings, but the needles, jets, etc., would likely outlast everything else.

[chopzuki]

Ok I mistook the idle mixture screw for air screws. I blame it on my inexperiance with cv carbs. And I rebuilt the carbs because the bike sat for years before I got it, which is why it only has 4000 miles. But I actually did figure out the problem, I just took the bike on a 200 mile trip yesterday and it ran beautiful. I'm not sure if this is a common problem or not but when I'm riding normally, with my feet on the pegs, I can barely hit 40mph. When I pick my feet up and rest them on the cases, the bike runs great all the way up to top speed.


The bike has pod filters, could my legs be blocking them? They're a good 2-3 inches away while riding normally. With my legs up however the filters have easier access to air, maybe with my legs down a low pressure area is creating thus richening the carbs? Hopefully someone knows.

And are forward control kits available anywhere? Or possible?

[Steve]

Ok I mistook the idle mixture screw for air screws. I blame it on my inexperiance with cv carbs.

That's OK, you are not the first (nor will you be the last) to do that.

I rebuilt the carbs because the bike sat for years before I got it, which is why it only has 4000 miles.

Commendable attitude. Some guys would have thought "... but it only has 4000 miles on it, it shouldn't need anything."

I actually did figure out the problem, I just took the bike on a 200 mile trip yesterday and it ran beautiful. I'm not sure if this is a common problem or not but when I'm riding normally, with my feet on the pegs, I can barely hit 40mph. When I pick my feet up and rest them on the cases, the bike runs great all the way up to top speed.


The bike has pod filters, could my legs be blocking them? They're a good 2-3 inches away while riding normally. With my legs up however the filters have easier access to air, maybe with my legs down a low pressure area is creating thus richening the carbs? Hopefully someone knows.

Nice to have found a (partial) solution. The problem seems to be related to air flow, but there is no way you are blocking air to the full circumference of a pod filter. The only other thing that I can think of that would relate to turbulent air is your carb vents. Do you still have the vent hoses on the carbs? If so, the ends are probably in turbulent air, which upsets the atmospheric reference that is necessary for the carbs to work properly. Most of the guys that have pods will say to remove the vent tubes. Personally, I believe you can leave them on, but make sure the ends are in an area of relatively still air.

And are forward control kits available anywhere? Or possible?

With enough time, money and creativity, anything is possible, but there are no ready-made kits for that bike.

.

[7981GS]

On all of my bikes with pods, I run the vent tubes to just in front of the battery or under the seat.

Daniel

[keman]

Yep, pull the air vent hoses ,or Tuck them out of any possible rough air.

Mine are currently an inch long aimed straight up. (My OCD will not let me leave an exposed nipple fitting be)

[Steve]

Mine are currently an inch long aimed straight up. (My OCD will not let me leave an exposed nipple fitting be)

OCD or not, what difference does one inch make?




By the way, I suffer from CDO.
It's pretty much the same as OCD, but it's alphabetized, as it should be.

.

[Normk]

Good catch on the vent hose position as a likely cause!

I keep forgetting about that despite having been bitten by the KLR650 water issue. Riding one one the road in the rain, the drops of water flying around will often enter the bowl vent hose due to the small air flow up the hose. The emulsion tubes in the bowl pull a bit of air which is just enough to hold the water or cause a slight upward flow.

The water restricts the vent hose enough for the emulsion tube air flow to create a low pressure in the bowl. The fuel flow reduces so the engine goes lean, stumbles, CV drops, bowl vent air flow reduces, water drops a bit, and the whole thing goes around again. It feels like an ignition miss so many of us chased the wrong symptom believing that the wet caused an ignition problem. It is surprising that more bikes don't experience this kind of problem.

[keman]

OCD or not, what difference does one inch make?




By the way, I suffer from CDO.
It's pretty much the same as OCD, but it's alphabetized, as it should be.

.

One inch makes it not a naked nipple! Dangit they made that nipple to have a hose on it. ..

I could not just leave it there with no hose! You thought I was kidding about the OCD huh?

As for performance. .. nope it does nothing but satisfy my crazy.

[Steve]

..., the drops of water flying around will often enter the bowl vent hose due to the small air flow up the hose. ...

I never have figured out what "air flow" there is in that hose while riding.

The only possible reason there would be any air flow is if the float level changes, and the float valve is supposed to keep that rather constant.

One inch makes it not a naked nipple! Dangit they made that nipple to have a hose on it. ..

I could not just leave it there with no hose! You thought I was kidding about the OCD huh?

No, let's feed that OCD.

It was supposed to have a hose that was SEVERAL iinches long, not just one.

.

[1948man]

My hoses drape down in front of the rear wheel. Would it be better to rout them in a slightly upward path to the area of the battery box or under the seat?

[Steve]

My hoses drape down in front of the rear wheel. Would it be better to rout them in a slightly upward path to the area of the battery box or under the seat?

Depending on the model, the stock location is either over the back of the airbox or on top of the battery, under the seat.

The important part is that they are in an area of no turbulence, so they have a good atmosperic reference.

.

[7981GS]

My hoses drape down in front of the rear wheel. Would it be better to route them in a slightly upward path to the area of the battery box or under the seat?

That is fine.
I have run them that way for over 30 years.
Along with all of the other odd breather hoses. Airbox drain, battery drain, fuel tank drain...

Daniel