I finally bit the bullet and have the Haynes manual coming in a few days. Bike is running now but just not how I'd like. Thought I'd ask in the meantime to see what you guys think.
I think it's running all on the left cylinder or at least mostly.
- right cooling fins are cool to the touch on start up and once bike is warmed up just hot
- if I pull the right spark plug the bike stays running
- bike runs fine once warmed up (tendency to stall before then) smooth power delivery throughout rpm range
- switching spark plugs did nothing
- think I band aided this problem by adjusting the carbs to more one side than the other months ago
- spark plugs are pretty black and there is quite a gassy smell, lots of quick backfires
Also, the choke only works wide open. If it's lower the bike tries to choke at a lower rpm then dies.
Ordered a shim tool and some feelers to check the valves as well today. I don't believe that's ever been done and the bike is an '06 with 2000 miles.
- Have you checked if you've got spark in your non firing cilinder?
- When you say, it runs fine when its warm, does that mean that both cilinders work then?
- Retune your carburettors. I used this guide, and tuned my carbs when i installed my powerfilters this week. took me an hour, but it works perfectly now :) not all steps apply to the gs500. The gascable adjustment step should be replaced with balancing your carbs :)
These links helped me tuning my carbs. I hope they help you a bit. For carb synching they use the idle screws i thing, you use your sync screw for that.
For your idle and fuel/air screw:
http://www.greasygringo.com/2011/11/synching-twin-carbs/
For synching your carburettor
http://youtu.be/HShbaC9ORSo?t=9m41s
I hope this helps you a bit.
Compression in the non running cylinder when bike is cold and you crank it over? Either by hand or with starter and finger on that spark plug hole, etc depending on what method you use for base check.
To check for spark do you just pull the plug, leave it on the boot, hit the starter and see if you get a spark visually on the plug?
What is the finger over the spark plug hole test?
To check for spark you pull the plug, leave it connected to the wire though, and keep something like a screwdriver about 1CM from the tip. crank the engine, and see if it jumps the gap from your plug to the screwdriver.
Your finger in the sparkplug hole test is to check by hand if you have compression. Im not to keen on such a method. The method above for the plug isn't very accurate, but for this method to work you REALLY need to know what you're feeling.
Air shoots out of the plug hole quite hard so I imagine there is good compression. I'll check the spark tomorrow to see if maybe that boot or whatever could be bad.
Quote from: zephyr_bike on August 11, 2014, 09:21:14 PM
To check for spark do you just pull the plug, leave it on the boot, hit the starter and see if you get a spark visually on the plug?
While it's definitely possible to do it this way, I don't recommend it. Only because there is potential for gas fumes coming out of the spark plug hole, and a source of non-contained ignition.
Take my word for it: fire spreads quickly.
Oh yeah - a 2006 model with only 2000 miles? Sounds like it has sat for a good length of time somewhere down the road. I'd be willing to bet your carbs are gunked up.
If your valves are in spec, check the carbs thoroughly. Assuming your ignition system wasn't damaged, it should be in good working order.
Carbs are really clean. That was what I did first when trying to fix the problem.
Clogged fuellines, fuelfilter, frampetcock or tankpetcock?
Quote from: zephyr_bike on August 12, 2014, 04:32:00 PM
Air shoots out of the plug hole quite hard so I imagine there is good compression. I'll check the spark tomorrow to see if maybe that boot or whatever could be bad.
Should hear a loud pop if there's good compression. Air swooshing out past finger does not confirm compression.
Also check to see if the plug wires are tight in the coils. Plug wires are screwed into coils and bonded in place and can't be turned if OK, if you can turn wire that could be the problem. Checking for spark in the conventional manner shows primary circuit is making and breaking but does not prove you are getting spark with plug in cylinder and running under pressure. Spark takes path of least resistance.
So compression is good.
Changed the spark plugs just because. Gap is perfect. Checked spark. I wouldn't say it was a fat blue spark for either plug. More like a little red line. The bike has been riding like this for 1200 miles though and I don't have starting issues.
Pulled the coils and measured primary and secondary resistance as per e Haynes manual.
Secondary:
30.7k
31.7k
Primary
5.0 ohm each.
Both coils are a bit out of spec on the secondary measurements. Could that be preventing getting a good spark and maybe the left cylinder just turns over better on the crappy spark? Should I not have the washer on e spark plugs?
What should I do next crew :)
Checked the valves. Not too bad of a job really.
They are all in spec, if looking down from the back of the bike they are
| .06 - .04 |
| .04 - .07 |
Someone mentioned fuel filter so I checked the on in the tank and all the lines. Replaced the air filter while it was all out as well.
Going to check the floats now since the carb is already pulled.
Very frustrating not finding anything wrong yet. Blech.
Looks like maybe the problem was a clogged main jet (the smallest of the three) on the right carb. No light would shine through it and the left carb I could see a small dot of light.
Also, the right carb looks really dry. A lot of white on the deposits jets. The left carb float bowls were dirtier though. Both old spark plugs were black.
That would be the pilot jet (the smallest one). That's the one the idle uses most - that, and the choke / enrichment circuit.
That would explain why my idle was so bad and the choke would only work on full blast or the bike would turn off.
Put her all back together and fired her up. Needed NO CHOKE to start and stay on! That's never happened. I think the last time I cleaned the carbs I didn't connect some of the vacuum tubes up correct and those are all connected right this time.
Bike sounds way different, ride really well, manged to even get her going in first with no throttle, felt heat from both cylinders.
Thought I had a hanging idle problem but it appears that the throttle cables are just too tight because if I twisted the throttle closed really hard it went back down to an idle.
Idle was around 1500 rpms. Didn't fiddle with the adjustment screw yet other than the bench sync I did. Super excited, hopefully the throttle cable fix tomorrow gets everything at 100%!
Sweet now you have a base on the other stuff as well. I think that exhaust valve was a bit tight in my opinion.. .08-.13 seems to be GSJacks suggestion with many miles reported.. It is still ins pec but may be worth changing if you go back in or keeping an eye on it.
Cool, I'll keep that in mind.
Went back the next morning and the tank was empty. The carb fuel hose had dry rotted mad split in half. Spent a few hours shoving new 1/4 inch fuel lines on, yuck.
Still running OK but with a bit of a very slow to drop idle. Could be due to the bench sync, I'll have to make a manometer this week.