Saturday, February 16, 2013

Rough Running Solved?

I originally posted this as a comment but thought that it was worthy of a short post (without any pictures).

Interesting engine behavior today. Last night, I connected a regular charger to the battery with the thought that maybe the trickle charger was unable to fully charge the battery. It was -19°F this morning so I moved the bike out of the garage to let it get cold soaked then try to restart. I was trying to debug the sluggish cranking. It started just fine first thing in the garage and I think the starter spun the engine significantly faster than normal. I left the bike outside for 5 hours to get thoroughly cold. Went out to start it and it cranked nice and fast just like it did earlier in the morning and would start and run for a few seconds then die. But would restart almost immediately and do the same thing. This sequence repeated itself about ten times. It eventually idled and I let it warm up a bit while getting geared up. Lots or restarts and each time the engine spun easily.

When heading up our driveway, the engine would start to sputter as if out of fuel by the time I reached the top of the driveway but after coasting back down, it would restart immediately. After this happened a few times I stopped, parked the rig, and thought about what could be causing the problem. It really felt like a fuel problem, maybe water in the gas? Since the rig has been moved in and out of the garage many times over the last month, condensation building up in the tank is a very real possibility. Especially since the air in the garage is fairly humid.

I added some Heet to the gas left in the tank and added another gallon of gas from a plastic jug to help mix the Heet with the fuel in the tank then emptied both fuel bowls. After a bit, I tried again and the engine started and I easily drove out the driveway. I drove around the subdivision hills a few times probably aggravating a few neighbors, the headed out on the road. Twenty miles of wandering around Fairbanks and the engine ran very smooth the whole time, just like normal. No hint of stumbling and I was able to restart the engine several times. I was careful to not shut the engine off unless I was near the top of a long downhill section, just in case. The road was extremely slick with yesterdays snowfall on top of ice and I could feel the rear tire break free more than once.

Possibly water in the gas or water in the carb bowls? And as far as cranking, the charging system may not be able to completely charge the battery on my short commute and the battery tender may not be charging the battery if its down to far. This fits with what the manufacture says about the battery tender that it is not designed to recharge a battery. Any thoughts? No opportunity for more testing for a couple of days as I'm sitting in the airport writing this on my way to Iowa State for a Northern Tier meeting. I've never been to Iowa State before so looking forward to somewhere new.


Unknown said...


I agree that a battery tender cannot charge a battery, esp in your minus temperatures. I have a newer digital battery charger which also has a maintenance mode, so this is able to actually charge and maintain your battery. It can charge 2,4 and 10 amps, plus around 100ma maintenance mode. It can also be taken off auto and pump 10 amps continuous if needed to "shock" your battery

your deduction of water in the gas could be the problem of stalling and restarting. Hope this is now fixed !

Riding the Wet Coast

Coop a.k.a. Coopdway said...

I'd agree with Bob about the Tender, something I've learned over time. You've got relatively short trips, lights always on, cold batteries are less efficient, any extra cranking would require more miles of charging all else being equal and IIRC, our RT's weren't known for having robust charging systems in the first place.

For the gas/water part, a garaged bike in your temperatures goes through many warm/cold cycles. Your big gas tank doesn't get filled every day or even every few days, even with your sidecar-added fuel mileage hit. Two gallons of gas in a five gallon tank leaves lots of room for condensation. On my early spring - late fall weekends I try to 'go to bed' with a full tank. 70 degree days and 30 degree nights aren't all that different from conditions you live with in winter riding.

redlegsrides said...

Short trips really aren't great to charge up a battery, which is why I keep mine on a tender....the R80 that is. The older and wider Airhead riders have mentioned the anemic alternators on our long is your commute? As to water in the gas, sure it could happen I suppose, keeping the fuel level near full is good advice....humidity here in Colorado rarely exceeds 30-40% so it's probably why I've not had that particular issue.

Erik R said...

Like Coop, I put mine away for the winter with a full tank and some Sta-bil in the tank. I have the 3 bike wired for a Battery Tender, and every "garbage day" I rotate the charger to the next bike. Each bike gets 1 week on, and 2 weeks off the charger. It seems to work good. I can go out in the garage and hit any of the start buttons and they'll pop to life! But, the garage is attached to the house and even this morning at -6°, its still only 26° in the garage.
I hope the HEET works for you. Did you let the bike cool off again so you could recreate the conditions of earlier?

RichardM said...

When the bike has been on the tender, the voltage would always be reading up around 13.8v so I assumed that it was fully charged. When the regular charger was used, it read 14.6v.

The humidity in our garage is really high as the clothes dryer vents into the area through a lint filter. Plus a lot of moisture is brought in with the two cars. There are some long periods when the tank on the bike was partially full especially since I was "borrowing" gas from the bike to use in the snow blower. Let's see if the problem continues.

You're right that these old airheads have pretty anemic charging systems. I have thought about the Enduralast system but have never really had a problem with capacity. Maybe with the sidecar lights, heated grips, heated gear, etc. it's now become a problem.

RichardM said...

I have a pretty short commute, only about 5-6 miles but I thought that as long as I had it on the tender at both ends, I wouldn't have a problem.

I usually don't fill up any of the vehicles until they get close to empty. Before this, it has never really been an issue. Then again, the bike is the only one with a metal tank. I think that condensation is less of an issue with plastic tanks.

RichardM said...

Yes, the bike was good and cold the other day when I did this exercise and just as cold when I was riding it around. Though it was getting up to only negative single digits...

Keith - Circle Blue said...

Hope the rough running was a "bad" fuel issue and the Heet took care of that. I have the Kymco on a tender all the time. The Symba has a a dry cell battery. I was a test and most of the other batteries Mike put in bikes have failed. They kept them on chargers. I haven't charged mine. It doesn't seem to have enough juice to start the bike when it has set out in the cold all day, but does fine once the little beast is started. Since kickstarting a 100cc bike is really easy I've just kept with this set up. I never put it on the charger, but when ever we test it, it is fine. Go figure. Mysteries of the universe.

Hopefully your mystery is solved for now.

Jack Riepe said...

Dear Richard:

I haven't had to think in terms of -19º(F) since leaving upstate New York. It was 17º(F) here yesterday (NJ), and I was horrified. I am beginning to think there is a sidecar in my future.

Fondest regards,
Jack Riepe
Twisted Roads

RichardM said...

Originally, I was looking for a bike with a kick starter but they are starting to get harder to find. If I was in the market for a bike now, I probably would be looking for a Ural complete with sidecar, 2WD and a kick starter. I didn't even know that they existed back then.

RichardM said...

One of the benefits of NJ is that you don't need to think about negative temperatures. Nothing wrong with a sidecar. I'm thinking that I may really enjoy this even though the original motivation was winter riding opportunities.

I've been reading your book on the airplane flights. Thoroughly enjoyable reading so far.