Jetting my 78 GS1000

[80GS750]

ive got my smart charger connected to it the whole time, that way she stays good while i try to get her going.....

[80GS750]

ok keith,

i have the engine back together now... but cant get her to start...

with all the slides all the way down, very close to the same height in relation to each other.... i can move the idle screw from bottomed out to all the way up and still i get nothing out of her....

unless i choke it... then it runs for maybe 3-4 seconds and dies....

i was messing with some adjustments and was able to get it to run for maybe 20 seconds, then i killed it, and i cant get anything out of it now....

it was running like crap. so i think my timing is off. the manual really sucks in this department and i cant get it set where it should be....

what i need is either someone to help me out, or a step by step with pics too.....

thanks in advance keith.

[KEITH KRAUSE]

The timing should be verified correct before start up. You can't vacuum synch without the timing correct first.
Do you have stock ignition or a Dyna S or ? Make sure the timing marks line up as your manual states. You can statically check (key on only/plugs removed and watch for spark at #3 and then check #4 spark) by turning the crank with a 19mm wrench. You can check advance by doing the same thing but holding the advance mechanism at full advance with your thumb/index finger. Crank slowly as the correct mark comes around and when the marks line up nicely you should see the spark snap. Good enough for start up purposes. Once running/warmed up, you can fine tune the timing and then synch.
If that's not your problem, are you using the gas tank with extended fuel/vacuum lines for fuel and vacuum/venting? If using a temporary reservoir or the tank are you sure it's vented properly so fuel will flow? Is the vacuum port at #3 plugged as it must be if using a reservoir?

[80GS750]

i will check the timing like you said too... never thought of it that way.

im using a reservoir, thats vented so the fuel will flow.... and i have a plug in the vacuum line so that it cant draw in air through it...

[80GS750]

what im thinking is this:

it starts when i choke it, so the mixture must be too lean the way i have it right now...

so i may try to adjust the air screws a tiny bit at a time, then try moving the slides up from the bottom as i crank it and see if i get better results with different mixtures....

both the air screw on the side and the fuel screw in the bottom are for idle purposes correct? that makes it tricky to get it stoich without having it running first....

[80GS750]

shes alive!!!!!!

but not sounding healthy at all....

i can only get it to hold an idle for an extended period of time with the air screws 1/4 turn out....

i mean i seat them gently, then turn them 1/4 turn out... thats it.

whats the deal with that? thats where it idles the best... and its mostly running on 1-4, 2-3 are not doing much really...

im gonna mess with it some more and get some video for you so you can hear what she sounds like...

im getting some kind of low rattle in it.... at low rpm.. it seems to go away around 1500-2000

weird.... more to follow

oh and when i give it throttle, it dies.

[80GS750]

ok.... i got the highest idle thing with the air screws all the way in.... it runs the smoothest with them all the way down... i know thats not good


once it warms up a little bit, you can rev it a little, i only go to about 2500 rpm at most... and she comes right back down to idle, which is good...

but i noticed that when i pull the choke on, she revs way up!!!!

im running way lean!!! how do i correct this? different pilot jets???

[80GS750]

well i turned the fuel screws out 1/2 turn, then went to turn it over and my damn rotor bolt came loose again....

now im ****ed. time to quit for the night. this is like the 7th time is has given out on me!!!!

i torqued it down past the recommended setting last time too... it just keeps working its way loose... im gonna get some locktite tomorrow and that will solve my problem!!!

not the permanant stuff, just the regular kind

[80GS750]

ok well i have it running...

it sounds the best at around 2000 rpm

lower than that and she gets really clunky sounding...

i have to choke the crap out of it to start it up, and once it warms up a little bit it will idle for me just fine....

if i rev it up to around 3k or so she starts popping, like backfiring....

i have a leaky bowl gasket on #2 so im gonna pull the carbs and replace it, ill do a quick look too just to make sure my floats are set right and everything else looks ok.

it sounds like im lean? if i choke it when shes idling the rpm goes way up...

[80GS750]

i have the fuel screws at 1 3/4 out, and the air screws at 3/4 out....

[KEITH KRAUSE]

Red lock-tite should be used for the rotor (alternator). The shaft must be super clean and dried first.
Not sure what you've skipped or missed but something's wrong if the bike idles best with the side air screws only 1/4 turn out. Initially setting them to approx' 1 1/2 to 2 turns out is generally good enough for start up purposes. When fine tuned, they end up around 1 1/2 to 1 3/4 with your mods in most cases.
What are all the "basic maintenance" things you've done so far? These are things that should always be checked/done on any older bike, especially if you have no idea of it's maintenance history. Float levels as you mentioned are just one of many checks. You also say 2/3 cylinders aren't making much power? All those things would be taken care of or at least the problem determined with a basic check list. It takes time to fully check and tune a bike and if you're taking short cuts or assuming some things don't need checking, that's a good way to end up frustrated and spend even more time diagnosing/fixing things.
Any chance you have pilot fuel screws with broken tips still in the carb bodies? That would make it lean and cause problems as you say you have. If not, I think the carbs are dirty inside or?

[80GS750]

im starting to think i may have other issues also...

i put the bike back together... so i went over pretty much everything to make sure it was all either new or in tolerance...

i am thinking something may be clogged or not right in the carbs cause everything i have read shows that she should be running by now..

im gonna take the carbs off when i get back into town, tear them down again and check everything out for sure, again.

i will reassemble and put everything back to a starting base line and then report back...

we'll see what happens

oh i will be out of town for a week, so it will be a little while before i update

[80GS750]

well

SHE RUNS!!!!

you were right with the settings.... just about dead on. i had a bunch of stuff that must have come loose and clogged up my idle circuit... i took the bowls off and dipped them to get the gunk out, again... and now it runs.

i took her out on the road, and she accelerates good, but wont slow down at all...

i have to use the brakes to slow the engine down, any ideas?

im thinking mmaybe i need a stronger throttle return spring? maybe...

i dont know.

thanks keith

[KEITH KRAUSE]

It's easy to see if the slides are seating correctly and/or the throttle pulley is returning correctly. If so, I don't know what could be happening.

[80GS750]

i took a look at the spring and the way the slides seat and they look good... no issues there....


someone else said they had the same issue when the intake boots were old... so im gonna order some new ones and see if that fixes it...

mine are older and are kind of hard.. so its hard to say if they are leaking or not..