1986 Mint Low mileage GS550ES hard to start/ dies/sputters until very warm

[Corvette95]

I have had my 86 GS550ES for 20 plus years, mint, low mileage survivor just almost 3k miles. It sound like carbs.....duel two barrel, I have taken it to 3 dealers -all of whom cleaned and adjusted carbs----basically no change. I only use non ethanol gasoline and store it carbs drained. Taken it to carb specialist, still another clean rebuilt, adjusted valves (two different times) even put jet kit in and then put new original jets backs in. ALL STOCK... hard to start when cold, sputters and have to ride with chock on in 90 plus degree weather for many miles. I have idle high so it won't go dead even when warm. My uneducated possible additional cause could be a coil going bad, that all spark but maybe not 100%. I have a factory service manual I take to all these shops, but they just keep doing the same things and giving it back to me in the same condition as when I took it. The plugs do get dark (rich?) so it runs better for a while when I get it back with new plugs (100 miles). I understand that the two inside jets are different than the outside jets...or so some have told me. I want it run like it should when it was new.....it looks new, I have not declined any recommendations from any service department. I don't know what to do at this point...any tips or help? I am in Huntsville, AL. On a much lesser note.....where can I have the wheels restored to new condition if anyone knows...thanks in advance!

 

[Guest]

Just a thought. Have the O rings behind the carburettor rubbers and engine been replaced. If they are the originals they will have perished and split. Also consider replacing the retaining bolts with stainless steel ones and a bit of anti sieze grease. These guys come recommended http://www.cycleorings.com/

good luck,
Greg

 

[Big T]

Your 30 year old bike is in need of some TLC

It does not appear that anyone you've taken it to so far knows what to do. Adjusted the valves twice? Didn't know how to do it the first time?

It's clearly running very lean and probably the cabrs are not yet clean. How does the inside of the gas tank look? Rusty?

 

[roeme]

Described conditions indicate the engine drawing false air.

1. Most likely the intake O-Rings, but make sure the vacuum inlet screws are clean, tightened and make a proper seal. I had those become loose, road grime filling the gaps and making for a very weird engine behaviour. This is a 1-minute check&fix that has the potential to save you a lot of time.

2. If the screws are good, replace the intake O-Rings before doing anything else, lest you want to spend a needless amount time chasing faults that aren't there.

3. Read the top 10 newbie mistakes thread.

4. As said, TLC. Get to know, and learn to work on your bike by yourself.

I don't think it your coil(s) are bad, you would definitively know it, as you will lose a _lot_ of power.