1980 gs550 coils on a 1982 gs650. bad idea?

[bustinjustin2k]

Hi all,

I've been having problems with my coils so I went to a used motorcycle shop for some used coils the "salesman" at the counter gave me some coils from a 1980 gs550 and my bike is an 1982 gs650 I made the wires fit just fine, but thats a 100 CC difference. They do appear to work, I had spark on each and every spark plug, even got the bike to run for a whopping 5 seconds. However it ran veeerrrryyy poorly sounded extreamly weak like the rpm was at 100 is possible. After it started for those 5 seconds it wouldnt start again, it did SOUND like it was running as I held the starter on but that cant be good, it should just fire up.

Since the coils were ment for a 550 bike would that cause the problem?

The guy who sold me the coils guaranteed them to work but he dosent guarantee that its the problem, and since they do produce spark and all they DOOO work and thus.. he wont take them back. I love service people..

My carbs are clean but probably not in sync right now as its not running to sync it. Even if the carb was way out of sync though it would still run just sound bad right?

Your thoughts?

[Anonymous]

Justin, I might think that your problems could be elsewhere. Have you just now put your carbs back on? If so, you might not have good fuel flow to all of the carbs especially if your bike has a vaccum petcock like most do. Try pulling the vacuum line off the #2 carb, the one which also connects to the petcock. After pulling the line from the carb, try turning the engine over and start sucking on the vacuum line, this will get prime back to your carbs and with a little luck will get it running again, unless your problems are elsewhere.This is what I use to do before I installed a Pingle hi flow fuel valve.

You can also pull a couple of the drain bolts from the float bowls to check for flow. I thought I had coil problems on my 1980 GS550 a few times and even installed Dyna Green coils in the process and it just ended up that I didn't have sufficient fuel flow. If you get it running you might want to check for vacuum leaks around the airbox connector boots and the intake boots. After I reinstalled my carbs, I couldn't get the airbox boots to pull up and seal off at all. That ecouraged me to go with a pod set up and a Dynojet Stage 3 jet kit. But don't do that on my account. Make sure your battery is charged good.

Hope this helps

[Anonymous]

Coils

My first suggestion would be that the wires on the coils are possible backwards. I am referring to the power wires coming from the ignitor unit.
Just double check them. If they are backwards, it would cause the engine to fire on the downstroke of each cylinder. Hence the appearance that it is "running" while you have the starter button depressed, and then "dies" when you let it go.

Just check it and see, hope it helps !
:?

[bustinjustin2k]

thank you both for replying MountainGS Im sure the carbs are ok I went through them about 4 times now, petcock is perfect. Fuel flows nicely.

Dallas I double checked the coil wires and there on correctly.

I actually got the bike to run for a good 30 min, didnt ride it just "tuned it" heh.. Shut it off and returned to it 4 hrs later and it will no longer start even with the choke on. Ill start another topic later with more information.

Just wanted to say thanks.