Put to bed fine, now won't run without choke

[J_C]

I've been trying to slowly get back into riding again - a month ago I got everything running fine, new battery was all it took, ran it around the neighborhood and all seemed a-ok. About a week ago I noticed the battery meter on my bike was reading really low so I put it on a tender.

Today I thought I'd take advantage of the weather so I went to start it up, but it will not run without heavy choke. The moment I hit the throttle, it dies. No idea what could be causing this, when it was running fine 5 weeks ago.

Any thoughts? Thanks GS friends!

[hampshirehog]

I would suspect that you have some gumming in the carbs or some muck has settled in there and either way you have some blocked jets. Try running some Redex through there and see if it clears. Always worth a try though you may have to strip and clean the carbs.

[J_C]

Thanks for the reply... I sure hope that isn't the case. I drained the fuel before putting it away 2 years ago, and added gas only when I got the new battery and started it up last month. The gas I have in there is only 1.5 months old, and I had put some some sea foam in it, so I can't imagine there would be any gumming or varnish. (Anything's possible of course)

[Steve]

Just so you know, adding ANY throttle while the bike is running on "choke" will likely kill it, or at least make it run VERY poorly.

That is because there is not a true choke on these bikes, they use an enrichment system that relies on the high vacuum of a closed throttle to draw air and fuel through the enrichment system. Opening the throttle AT ALL will reduce that vacuum, forcing the engine to try to run on the stock (leaner) jets that it uses when everything is warmed up.

Using the "choke" to start the bike is rather normal. If the bike has not been run for several weeks, you might have needed to put the petcock on PRIme for a few seconds to fill the float bowls before trying to start it. From the limited information given, it sounds like you gave it full "choke", then tried blipping the throttle. The "choke" system was barely working, and only because it draws its fuel from the bottom of the float bowl, but when you blipped the throttle, you were asking it to run on the "normal" jets, which did not yet have the fuel they needed to run, because the fuel level in the float bowls was low.

Just a thought, but that's what you were asking for.

.

[J_C]

Many thanks as always Steve. I went back out and made sure to prime the bowls. Then it still wouldn't run without choke. In fact, I needed to keep increasing the choke little by little just to keep it alive. Exhaust was very rich smelling as well. Looks like no riding today

[1948man]

Any chance it ever ran rich enough to foul the plugs at some time?

[azr]

Any chance it ever ran rich enough to foul the plugs at some time?

Good point there. I'm just thinking off the top here, are all four cylinders firing (pipes heating up at least a bit before she dies). You could have some bad plugs. Is there fuel getting to the plugs? you might as well yank them all out and see what's happening in there. My thinking is always try the simplest things before jumping into the more complex, like the good advise hampshire dog gave you.

[Nessism]

I'd give it an extra shot of Seafoam and see if you can coax it out on the road. Most likely just some minor blockage that will clear up with a little exercise.

[Katarat]

Sounds like the pilot jets are plugged

[J_C]

Thank you everyone! I'll have a look at the plugs tomorrow, and add some more sea foam after that.

While all four cylinders are firing, it's very possible I may have fouled the plugs. The last few times I have had the bike out it's never been above 5k rpms... all neighborhood riding. I'm wondering if I somehow fouled them and then it wasn't until the bike got cold that it really caused a problem?

Boy, you'd never think that at one time I possessed the knowledge to take this bike down to the frame and back again. I guess all of that schooling wiped out the remainder of my brain.

[BassCliff]

Hey Jeff!

Long time, no see.


Did you do a quick test on the charging system? What's the battery voltage like at 4000 rpm?

Yeah, my first thought is also the carbs being gummed up a little bit, even after draining the float bowls. Do the Sea Foam thing like Ed suggests and then get tough on the carbs if you have to. Try some new plugs. Clean all the connections in the charging system and ignition system.

Do you think any critters might have made your airbox their home? Is everything still sealed up properly (intake boots, etc)?

It's good to hear from you again.

Do you remember this ride?




Thank you for your indulgence,

BassCliff

[J_C]

Hey Cliff!! Great to see you - And yes, that's the one! I remember that ride well - what a great time

No critters, and everything sure seems sealed up right (no airbox - pods; and boots look ok) I'll definitely keep your recommendations in mind when I get to fiddling around again. Unfortunately I only have a few minutes today to look before heading out of town. So I'll definitely check the plugs. If I have time I'll drain the bowls and see if I can see any telltale signs of bad news. [I'll "save" electrical testing for later - ugh]

[J_C]

OK... all my plugs look ok (not fouled), and they're all gapped properly. Some are slightly tanner/grayer, but that's not bad eh?

Only one had a little gasoline on it, rest were bone dry.

[Steve]

While all four cylinders are firing, it's very possible I may have fouled the plugs. The last few times I have had the bike out it's never been above 5k rpms... all neighborhood riding.

That really dosn't mean much.

Earlier this summer, I was using my 850 to commute to work in New York. It was about 3 miles from the hotel to the hospital where I worked. Most days, it was very easy to stay under 3000 RPM, probably the most it would see withing a week's time was 4000 RPM. Never any problem with the way it ran. On the weekend, though, I would get it out on the mountain roads in the Adirondacks and "air it out", "clean the plugs", whatever you want to call it, but it ran really great all summer long.

If your jetting is correct, it wouldn't matter if you ran it at idle all day (as long as you provided some cooling).
It should run just fine at any speed or throttle setting.

.

[J_C]

OK thanks for that info Steve. Very helpful.

Then that means the only known change between when I put it away and now was that the battery was allowed to run down. I don't think there is a correlation there, so it could be completely unrelated - I'll try and tinker more this afternoon if I get home in time.