Returning to a GS that wouldn't start in the cold. What should I bring?

[Guest]

On Tuesday, I came out of my night class to a bike that just would not start. I ended up having to catch the bus home (luckily it was a simple route home) with my battery in hand.

This is the first time that I've had to abandon the bike because of it not starting. But, I've noticed that it's been getting more and more hesitant to start as the weather is getting colder. The bike was turning over fine, the battery was strong and I got a good 10 long hard attempts be i gave up. I even had the help of some jumper cables and a car battery - no luck.

So I've charged the battery back up, and I'll be taking it with me when I go back to night class tomorrow. What else should I bring if it won't kick over right away? would new plugs help? There are no hills around and I've never been able to bump start it (alone, or with a friend).

fyi: I recently replaced the intake boots and the bike has been running really good since.

[7981GS]

Bring a spray can of carb cleaner to use as a starting aid.
And a friend with a trailer or truck in case it doesn't start.
Also, something to place into the spark plug boot to check for spark.

Daniel

[LoopGaroo]

It's weird, but I don't know a single person with truck in Chicago. I might be renting a $20 uhaul.

So just spray a little carb cleaner into the spark plug holes?

[7981GS]

If you have a factory airbox, spray it into the tiny little opening that allows air into the motor.
If you are running pods, just spray a little bit on top, near the front of each filter.

Daniel

[bonanzadave]

Also, something to place into the spark plug boot to check for spark.

Good idea. Do that first or just pull one of your plugs. Gotta have spark or take the bus again.

Pull the fuel line off the petcock and then turn it to PRI. Got fuel ? Reconnect the line and try it.

[7981GS]

WTG Dave!
It is often the easiest things that are over-looked.
I had a friend call me many years ago at 2 A.M. to ask me for help with his car that was broken down on the side of the road and he swore that it couldn't be gas.
I brought a few gallons anyway and poured it into his tank except for a little to prime the carb and sure enough, he was out of gas! LOL!

Daniel

[bonanzadave]

It is often the easiest things that are over-looked.

I picked a rider up off the freeway. Out of gas. Went to my house (2 miles) got a can of gas. Went back to the Bike. Q-"Did you switch to reserve ?" A-"Whats that ?". Started right up.....

[srsupertrap]

I would bring a new set of plugs with you too because you stated its been getting harder and harder to start as the weather turned cold. I am guessing you may have spark but its an easy check as stated earlier.

If the car battery could not start it & you have spark that tells us something about your GS is really nominal (charging system, carb tune) When was the last time the plugs were replaced? If you pull the plugs and they are black don't be tempted to say its fixed by installing a new set. Do some research into charging system health & coil relay mod to discover the real problem.

Just my $.02

[DanTheMan]

Here's one that got me for awhile. Both of my bikes will start easily in cold weather with a well charged battery, 5w/30 oil and a lot of choke. I've never flooded them, though I thought I had. Make sure your choke is fully open, on my 850 it isn't (stretched cable) without me clamping the cable with a clothespin to hold it all the way open. I don't have a working clutch safety switch either, disabled that long ago.

[tkent02]

Poor cold starting is the classic symptom of tight valve clearances. When is the last time you adjusted them?

[LoopGaroo]

I've got a long list of winter projects. Checking my valve clearances is definitely on it. I'm leaving now to go check it out. I think it's a fuel delivery problem, I remember some bogging on the highway ride on Tuesday.

I think my fuel gauge might be exaggerating the amount of fuel in the tank - wouldn't be the first time.

I've only had the bike since spring, (and it's my first motorcycle) so I'm still determining this bike's "uniqueness."

[anthonygs1000]

Poor cold starting is the classic symptom of tight valve clearances. When is the last time you adjusted them?

TWO THUMBS UP ! valves are my bet

[LoopGaroo]

I walked up to the bike, installed the battery, flipped the petcock to RES, and it fired up first try. Fuel gauge showed about 45%. It was about 10 degrees warmer though...

I think that on Tuesday, when it wouldn't start right off the bat, i flipped it to PRIME to help it out (that usually works). Will the prime setting pull from the reserve?

[7981GS]

I walked up to the bike, installed the battery, flipped the petcock to RES, and it fired up first try. Fuel gauge showed about 45%. It was about 10 degrees warmer though...

I think that on Tuesday, when it wouldn't start right off the bat, i flipped it to PRIME to help it out (that usually works). Will the prime setting pull from the reserve?

Yes. Just without the vacuum assist.


Daniel

[Normk]

Low compression shows up most graphically during cold starts. That is why tight valve clearances have that effect. Slow cranking allows more time for leakage past piston rings and (too tight) valves to a combination of slow cranking speed and cold conditions ......

Often cranking from an (not running) automotive battery provides a high enough cranking voltage to turn fast enough to compensate but that does not prove that the battery is poor, but simply that it is smaller than the automotive one.

A flooded engine, one which has been overheated and parked or one which has been stored for an extended period may suffer from lack of oil on the upper cylinder walls and compression rings. In the case of the flooded engine, the excess fuel will wash the oil down. Heating and long storage can clear the oil due to evaporation and thinning or time. A squirt of oil into each spark plug hole, followed by spinning the engine over 5 or 6 times before reinstalling the plugs to try for a start can often be the answer.

The problem is greater in older engine designs and seems also worse with breaker point ignitions because, I infer, it is more difficult to fire a lower density charge. This is also why a new set of plugs may get a compression or mixture compromised engine to start, however reinstalling the used plugs may allow it to continue with no apparent difference. Sometimes the variables line up too far into the negative and it simply doesn't go that time. This is to say that simply replacing the plugs may not have solved the root cause in such a case.

Lots of quality suggestions already posted but thought a clarification might be useful to someone.

When you have the bike home and some time, you may wish to take a compression test in order to indicate whether compression pressures are lower than ideal. This may indicate that further action is required. If you have a leak-down tester, so much the better but a compression test is usually sufficient to diagnose low compression although not reliable for predicting blow-by.

If the bike has been stored for an extended period, run with rich mixture for an extended time, short trip/around town use, an oil burner, etc. the issue may be build-up of combustion ash on the exhaust valve faces and seats. The intakes may have a similar build-up. A combustion chamber cleaner such as GM's Kleens (sp?) can clear this material, resulting in a return to normal compression pressures. While this is less common with motorcycles than automobiles, we used to see the effect on larger displacement bikes used around town. Don't put combustion chamber cleaners into the engine oil! The method is to mist/vacuum/dribble the liquid into the intake of a warmed up, running engine. Take care not to dump in a large amount or a cylinder may be hydrauliced.

Just some thoughts which may be of interest.