Still not right - carb maybe?

Spark plugs seemed to help for a day or two. Seafoam to counteract the Ethanol seemed to help for a day or two. When I was in Montana, where they have less gas with Ethanol in it, the bike was running a little better. But now it's worse than ever.

The main thing it's doing is when I twist the throttle open and am running up through the gears, it starts choking and sputtering. It used to be at higher RPMs, but that ceiling is getting lower and lower.

Any ideas? I have a 42mm Mikuni carb, in case that matters.

One other thing... When I had the air cleaner off at some time in the last few months, my friend noticed that a hole in the plate that holds the cleaner on was open and not plugged after a bike shop rerouted something to keep the breather from barfing oil onto the engine (in between the front and rear pushrods) from time to time. He plugged the hole, but now I wonder if that should have been left open. I can take a picture when I get home it isn't clear what I'm talking about.

Hi Hot1 ....If the hole in the plate is where air could be drawn in your motor without being filtered ..it should be plugged...I'm not sure if ethanol would hurt any parts in your carb...someone else might be able to answere that...good luck on getting your bike running better...Al

I had similar problems on my trip, low power, fouled plugs, etc. My probs where due mostly to high altitude. The CV carb can only adjust so much. I would have said the same bout yours cept yours is already tuned to high altitude since you live in CO. I thought that the Sinclare gas was crap, but again it was probly due to tuning and altitude for me. I had to buy a K/N cleaning kit and one point, and cleaned out the plugs too. it helped but my gas mileage was still very low.

You should plug that hole and re-tune the carb.

I was thinking I should have dropped a main jet size before I left.

OK. I can't remember the time frame. I'm at the coffee shop working on the book. I'll take a picture when I get home.

It was similar to how my bike acted when I was living at sea level and was in Utah and Colorado on the cross-country trip. I kept thinking about that, but it didn't make sense since I'm now jetted for altitude. My gas mileage was sucking too, but there were a lot of miles at 80MPH plus, and I doubt my tent and sleeping bag on the handlebars was aerodynamic.

agreed. a lot of 75 to 80, head winds and side winds, hills. I did 4000 miles in 8 days. My old ars is glad to be home lol

The hole is where the breather hose was connected so the engine would suck blow-by oil back into the motor, it is common to remove that hose and route a hose under the bike somewhere to eliminate oiling up the air cleaner. If you are losing power and engine is coughing, it sounds like an intake leak. Have it checked to make sure because you dont want a lean condition to cause damage to your motor!

I changed the plugs and checked the wires a month or so ago. I'm not against replacing the wires, but wouldn't that cause it to run rough all the time? This is only happening when I'm accelerating quickly up through the gears - high RPMs. Once I'm in 5th and cruising along, no problem.

OK. I have changed the petcock once, right after my trip in '07. Every time I started going uphill (in NH, that's all the time), it would choke and die, until it just quit altogether.

I will check the vacuum line and all the other stuff. I think it's fuel starvation of some kind. That's what it feels like, but I've been wrong before.

Thanks