G
Guest
Guest
Hey guys, this is my second GS, 1978 GS750 (I think E?). I bought it, knowing only 1 & 4 were firing, and it came with a spare engine. Gamble I was willing to take (and it seems to have paid off so far)
I'm having trouble getting cylinder 2 & 3 to fire, here's what I've tested so far:
-Good compression on all 4 cylinders
-Coils/wires with spark plugs out and grounded to engine produce spark (all 4 of them)
-Carbs are incredibly clean (someone went through them clearly)
--Carbs are also rejetted 117.5 main 20 pilot...PO had pods on, I'd like to keep them this time..considering replacing with UNI's, but that's another topic..but this seems a tad rich? Idk.
-Engine manifold boots are new, no cracks, nice soft rubber (trying to rule out excess air issue...but here I feel excel fuel but idk)
-Condensers check out fine
-Timing marks line up with the left most firing order mark (there are two marks like |F1-4| and |F2-3|)
Another thing to note, petcock has bad gasket (on order) and was continually giving fuel to carbs. I haven't put carbs back on yet and checked to see if vaccuum tube was filling with fuel and causing my #3 to not fire, but wouldn't explain #2 not firing I don't think? Or would bike have not even fired up if vaccuum was plugged?
Now, plugs 2 and 3 do get wet when I fire her up. They go in sparking and come out fouled.
I'm looking for next things to test. I'm learning about points and condensers still, will check point gap next.
Sorry I'm all over the place with info, but want to throw it all out there!
-MD
I'm having trouble getting cylinder 2 & 3 to fire, here's what I've tested so far:
-Good compression on all 4 cylinders
-Coils/wires with spark plugs out and grounded to engine produce spark (all 4 of them)
-Carbs are incredibly clean (someone went through them clearly)
--Carbs are also rejetted 117.5 main 20 pilot...PO had pods on, I'd like to keep them this time..considering replacing with UNI's, but that's another topic..but this seems a tad rich? Idk.
-Engine manifold boots are new, no cracks, nice soft rubber (trying to rule out excess air issue...but here I feel excel fuel but idk)
-Condensers check out fine
-Timing marks line up with the left most firing order mark (there are two marks like |F1-4| and |F2-3|)
Another thing to note, petcock has bad gasket (on order) and was continually giving fuel to carbs. I haven't put carbs back on yet and checked to see if vaccuum tube was filling with fuel and causing my #3 to not fire, but wouldn't explain #2 not firing I don't think? Or would bike have not even fired up if vaccuum was plugged?
Now, plugs 2 and 3 do get wet when I fire her up. They go in sparking and come out fouled.
I'm looking for next things to test. I'm learning about points and condensers still, will check point gap next.
Sorry I'm all over the place with info, but want to throw it all out there!
-MD
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