Pilot air screws located on a 89 GS 500?
I have been losing power with worrying results on the dual carraigeways. I took both plugs out and the Right hand one is Fouled to hell, indicating to me an over rich fuelling.
unfortunately at the moment, I have run out of cash to get it sorted properly so best home job will have to do.
Where is the pilot screw on the RH cylinder, how many turns would i anticipate coming out?
Yours in hope
Warren
(http://www.angelfire.com/mt2/mikesgs500/rejetting/tn_DSCF0130.jpg)
Here is a pic from the MikeT tutorial on rejetting
His main page is here and has tons of rejetting info
http://www.angelfire.com/mt2/mikesgs500/
If your pilot screws have never been adjusted you will have to drill out the cap. Which probably means removal.
Thanks,
I tried variations on the screw, and got it going up 80 ok, but then again a loss of power resulted. even slow speed pick up is poor.
I have also noticed that the right hand cylinder is running considerably cooler than the left also.
Any Ideas? :dunno:
I think the only way will be having to have the carbs sorted out properly, but that will have to wait. Is there anything else i can try whilst they are in situ?
Thanks
Warren
Warren,
Rich-running cylinders run cooler than usual, especially if your plugs are fouled and you're not getting good spark. For a little money, a homemade carb balancer tool might be just the ticket for your rough-idling problems. However, you can turn that screw until you're blue in the face (between 2 to 3 full turns out, by the way) and your high speed problem won't go away. It has other problems, including but not limited to:
--dirty carburetors; plugged jets
--carb floats not set properly. These affect fuel mixtures at higher revs.
--worn-out spark plugs. Cheap enough to swap out and see if your worries are over.
--other ingnition problems: corrosion in CDI connections, worn-out spark plug wires or coils, a bad CDI unit (let's hope not).
--poor compression due to rings or valves
--a sticking carb diaphragm or vacuum leak
Since you're riding an '89, and you Englishmen run your bikes in harsher conditions than we tend to do in the States, there are any number of possibilities that could be causing similar problems. If it was me... I'd beg, borrow or steal a repair manual and make a checklist of possibilities. Check them one by one, starting with the cheapest and/or easiest fixes, since your funds are limited. Best of luck; keep posting after you try a few things and we'll try to get you through this. You should find plenty of threads in the forum for these and other problems. :cheers:
PS. Try PMing Kerry also. he's the thread wizard. 8) :thumb:
JLKasper provided a good list of things to check.
Quote from: JLKasper--dirty carburetors; plugged jets
This is my prime suspect. Since your bike is 15 years old, I would be very surprised if the carbs were still as clean as when they were new. Do you know if they have ever been cleaned? Bits of rust or other grit can cause some mysterious problems.
Cleaning your carbs yourself is
free, except for an inexpensive can of carb cleaner. If you have a repair manual, 2-3 hours of time and the following tools you're in business:
* A 10mm socket for unbolting the side panels and a 12mm wrench (socket or open-end) for removing the fuel tank
* Pliers for the fuel hose clamps
* A set of screwdrivers, including a medium Phillips-head for various screws and a SMALL flathead for the jets themselves[/list:u]
Quote from: JLKasper--carb floats not set properly. These affect fuel mixtures at higher revs.
You can check the float heights WITHOUT removing the carburetors. See my
Float Height Check page for more info.
Quote from: JLKasper--worn-out spark plugs. Cheap enough to swap out and see if your worries are over.
'Nuff said. You might want to try this
FIRST. Make sure the spark plug gaps are set between 0.8mm and 0.9mm.
Quote from: JLKasper--other ingnition problems: corrosion in CDI connections, worn-out spark plug wires or coils, a bad CDI unit (let's hope not).
This falls in the "last resort" category. If you have tried everything else and start suspecting electrical problems, be prepared to either turn the bike over to a mechanic or to do some semi-tedious troubleshooting with a multimeter. (See the thread
Narrowing down the problems to a broken bike.)
Quote from: JLKasper--poor compression due to rings or valves
Hmmm. I take it back.
This falls into the "
final resort" category! BTW, how many kms do you have on the odometer?
Quote from: JLKasper--a sticking carb diaphragm or vacuum leak
The former should be sorted by a careful carb cleaning. The latter might require replacing one or more rubber-like parts that have dried out since 1989: hoses, O-rings, etc.
Like the man said - if at any point you have a question about how to proceed, post here FIRST. Keep putting off a trip to the mechanic as long as you can stand it. Because unless you've found a bang-up wrencher who will treat you right, your bike is better off in your
own hands than in
anyone else's. There's nothing worse than having to take the bike back multiple times because the mechs are rushed for time and can't spend the HOURS at your (and OUR) disposal to properly troubleshoot and diagnose the problem.
EDIT: Changed link from sisna.com to bbburma.net
Hey Skidz,
Like Kerry said, I'd try spark plugs first. I hope I didn't imply that your bike had ALL the potential problems I listed; that was more of a list of possibilities. A Haynes or Clymer (available in UK?) repair manual has a troubleshooting list that will help you track your gremlin down. :cheers:
Thanks for the replys :thumb:
One of my colleagues at work was a mechanic on bikes, and has all the gear. We have put aside Sunday Morning to have a look at the bike. I will print off the thread. thanks so much for the diagnosis, any others you could think of which i could print off as well would be most welcome
:cheers: :cheers: to you all
Warren
oh, it has 18050 miles on the clock
I would go ahead and check the valve clearance while you are at it. All four of my shims were out of spec at 16000 miles. Although, that was causing more problems with holding idle and in the lower revs but might be worth a check. The clearances should be between .03-.08 mm.
Also, if you are doing a carb synch the valves should be checked first.