1977 GS750 wont stay running. PLEASE HELP ME

[Anonymous]

OK, I left my 750 in my garage for 5 months without draining the gas or preping it for winter. I went to start it this 3 days ago and it would start. I took the air filters off and sprayed starter fluid in all the carbs. It took a few tries but finally started up. It was running ok but would go. I didnt warm it up or anything because i didnt have it licienced. I started it up without the starter fluid the next day no problem. Then i went to go take it to get saftey testing today and it wouldnt start. I checked my points and condensers and one was broke. I replaced it with one of my old ones. It still wouldnt start. I took the air filters off again and sprayed starter fluid in again but it would only stay going until the fluid ran out. I took the carbs off and the gas was getting to the float bowls. I dont know if it just isnt taking the gas for some reason. i put the air filters back on to see if maybe it just didnt have pressure or something to pull the gas into the engine. I just dont know what to do anymore. i have already paid for the insurance and need to get it running somebody please help me!!!

[robinjo]

Did you try installing new sparkplugs? they could be "drowned".

[Anonymous]

Non idling 750

It's very possible your idle circuit's are blocked. Fuel goes off and I've seen it turn to like a honey substance that completely blocks the tiny holes in pilot jets and the carb body passages. Actually I have had this exact problem. I did up and sold a bike for a mate and it had sat for about 2 years. It was hard to start but eventually it did and ran o.k. but would not idle. I stripped the carb soaked in a cleaner overnight, blew out all the passages and put wire through all the jet holes and carb body passages to get all the gunk out. It idled like a sewing machine after that.

[Anonymous]

After i posted that message i went and checked my plugs, and of course 2 were foul. i bought new ones and it worked great. but know i cant get the timeing to set right and was wondering if it would be better to just replace the points and condensers with only the electronic ignition. but until then do yo have any tips on tuning my timing

[Anonymous]

actually i was going to replave my points with a Contactless Electronic Ignition. what are your guys thoughts about this

[earlfor]

There is no difference between installing a Dyna electronic ignition and setting points and condensors. If you can do one, you can do the other.
If you are having trouble with one, you will have the same trouble with the other.
Learn to set the points and condensor ignition first. You will have to learn the process regardless.

Here's the proceedure for timing the 750. The points are located under
the round cover on the right end of the crankcase/crankshaft.

The round 6" plate that both sets of points are mounted on (breaker
plate) is held in place by three screws located at 12, 4 and 8 oclock.
Loosen the 3 screws on the breaker plate. Note that the screw at 12
oclock is in a slot. Rotate the breaker plate until the 12 oclock screw
is centered in the slot. Tighten the three screws.

We will replace the left side set of points first (located at 9 oclock
position) These are the points for cylinders 1 and 4.

Take a 19 mm wrench and rotate crankshaft until points are at widest
gap. Unscrew hold down screw on pointset and remove points. Note the
white wire that goes to the pointset and the placement of the insulator.
The insulator must be correct or the points will be grounded out and
will not work. Put the new points onto the breaker plate, set the gap to
14 thousandths, and lightly tighten the hold down screw. Install white wire.
Rotate crankshaft once again with 19mm wrench until points are at widest
gap. Check that widest gap remains at 14 thousandths. Adjust and
retighten holddown screw if needed.

Rotate crankshaft until rightside points are at widest gap (for
cylinders 2 and 3) Remove old points and install new points and set gap
at 14 thousandths. Note insulators on black wire installation. Rotate
crankshaft with 19 mm wrench again stopping at widest gap. Recheck gap
as you did with the left pointset. Adjust and retighten hold down screw
on points if needed.

THE ABOVE COVERS SETTING THE POINTS GAPS




Next is the timing:

Timing for cylinders 1 and 4 (the left set of points)....................
With 19 mm wrench, rotate crankshaft while looking through the timing
window and align the mark that looks like F1| with the timing mark on
the engine case.
(the line following F1 is the mark (|)

note: some bikes will have a stationary timing mark on the engine case
and some will have a mark on a stationary timing plate that can be seen
through the timing window)

Connect a continuity lights wire lead/clip to the white wire clip on the
left pointset. Clamp continuity light probe tip to ground on the bike or
battery negative terminal.

Turn ignition switch to on (do not attempt to start bike, just switch
ignition to on)

The continuity light should be on.

Loosen the three screws on the breaker plate located at 12, 4 and 8
oclock. Rotate breaker plate until continuity light just flickers out.
Retighten the 12, 4, and 8 oclock screws on the breaker plate.

Unclip continuity lead from left pointset.



For the Right pointset
Rotate crankshaft with wrench until you see the timing mark F2| become
aligned with the stationary timing mark on the engine case.
Connect continuity light lead to black wire on right pointset.
The ignition should be switched on and the continuity light should be on.

The right pointset is mounted to a breaker half plate.
You will see that you can loosen the mounting screws on this breaker
half plate and this will allow you to move the right pointset. This will
adjust the timing without changing the points gap. When you rotated the
complete breaker plate for the left pointset to get the continuity light
to flicker out, thats what you did. You adjusted the timing on cylinders
1 and 4 without changing the gap on their pointset.
Unfortunately, the whole breaker plate being rotated moves BOTH sets of
points, so that is why you must set the left side first and that is why
the right side is mounted on its own independent half breaker plate.
SOoooooo.... Smile Loosen the breaker half plate on the right side and
rotate as needed to cause the continuity light to just flicker out.
Tighten the half plate back down when satisfied with the adjustment. Smile

Remove continuity light and HOPEFULLY, start bike.

give a yell if you need clarification on anything.

Earl :-)

actually i was going to replave my points with a Contactless Electronic Ignition. what are your guys thoughts about this

[robinjo]

Say earl how about posting that info in the Tips and Tricks section too?

[earlfor]

No problem Robin. Done. :-)

Earl

Say earl how about posting that info in the Tips and Tricks section too?

[mcycle-nut]

Gas the points and put on electronic ignition. That way you set it once and forget about it. That is unless you ENJOY dicking around with points. :roll:

Ok Earl, I know you can do points in your sleep, it's just easier for some of us to get rid of them altogether.

[Anonymous]

i will try what you suggested but i saw this thing that was called a contactless electric ignition, but it wasnt made by dyna. the link i found was http://www.motorcycle-ignition.com/ignition_faqs.htm what is your thought on it. it seems cheaper but does it really work better? whats your thoughts

[earlfor]

Actually Kev, I dont have to mess with the points very often at all. Maybe every 10-12000 miles, I check gaps and clip a timing light on the bike. Its about a 15 minute job (if I stop for a sandwich midway). :-)

Earl

Gas the points and put on electronic ignition. That way you set it once and forget about it. That is unless you ENJOY dicking around with points. :roll:

Ok Earl, I know you can do points in your sleep, it's just easier for some of us to get rid of them altogether.