Baffled - In need of great minds

[Anonymous]

Just $.02 here. Believe that if you have clips on the needles, then you have Dynojet stage kits installed. If I remember right Dynojet mains are shaped different and smaller mains have greater fuel flow than stock.

[KEITH KRAUSE]

Just $.02 here. Believe that if you have clips on the needles, then you have Dynojet stage kits installed. If I remember right Dynojet mains are shaped different and smaller mains have greater fuel flow than stock.

Both Suzuki and Dynojet use 'C' clips to adjust the needles.

[Anonymous]

Re: Baffled - In need of great minds

Clip in middle slot of needle. My Mukini(Suzuki) carbs have only one slot. Needle height has to be adjusted using washers on stock needles.




[quote="frosty5011"]Bike - 1978 GS750E
Carbs - 26 mm VM
Air Filter - stock, foam - with stock airbox
Mileage - 12500

This time also made sure some previous person didn't originally have re-jetted for some other exhaust/filters/etc. Needle is in middle clip (standard), and the main jet sizes are #100 (I thought 102.5 was standard???).

[frosty5011]

OK......believe I'm a bit further now! I had the jets (labelled #100) measured at a machine shop, to see if they were "drilled out" - No, they weren't. So, I decided to take bike for a longer test ride, at higher speeds, to see how it was running there. Still rich.....doesn't matter whether idle, city or highway riding.

I then decided to double-check the points gap/timing. Set the gap to .014", then as I went to do Static Timing using my continuity tester, I see that there is "always" continuity, even when there's a gap in the points. This was not the case the first time I set the timing. This had me baffled, apparently something is grounding the points. I checked the condensers with Ohmmeter, as per the Clymer manual, and it appears they are both bad. I get an initial reading of around 5 ohms, then it drops a little, then settles around 4 ohms.

1. Do the bad condensers lead to the "grounding" of the points? I can put a lead from my continuity tester on each point, and get continuity reading, even when points are open and with a piece of cardboard between them.

2. Where does one get these condensers? Are they bought seperately, or do I need to get the whole "kit & kaboodle"? I see no marking on them, so I don't know if I could just get them at an automotive store...not know model # or specs. (OK, just found answer to part of this question. Cycle-Re-Cycle has condensers for 4.95/ea, and points for 6.95/ea).

3. Could this be what is leading to the constant rich fuel mixture?

4. What could lead to condensers going bad? Is it as a result of possible bad grounding somewhere, or a worse electrical problem? I had wondered why every once in a while I heard a "click" from the bike after a test ride. Sounded like it came from area of starter solenoid/battery box. Thought at first it was just part of the sounds engine makes when cooling...but was louder. Kind of like a spark plug "snap". Did it twice while sitting next to bike, setting the points gap.

As always, thanks for all the help you guys (and gals) have given.

[KEITH KRAUSE]

Re: Baffled - In need of great minds

[quote="MidnightRider"]Clip in middle slot of needle. My Mukini(Suzuki) carbs have only one slot. Needle height has to be adjusted using washers on stock needles.

Bike - 1978 GS750E
Carbs - 26 mm VM
Air Filter - stock, foam - with stock airbox
Mileage - 12500

This time also made sure some previous person didn't originally have re-jetted for some other exhaust/filters/etc. Needle is in middle clip (standard), and the main jet sizes are #100 (I thought 102.5 was standard???).

I did not mean all Suzuki's. Frosty has a '78, with VM26 carbs,which I believe use a 'C' clip to adjust the needle.

[KEITH KRAUSE]

I don't have any experience with testing condensers, but if they were grounding out I don't think you would get any spark to the plugs. As for the richness problem, it now sounds like it's all 4, not just #1 ? On your longer test ride I still don't think you were on the mains yet. If you were to 'mark' your throttle and turn it 3/4 in top gear, you'll be going about 100 mph. I really don't think your mains are the problem and if the needles are in stock position and your pilot jets are stock and your carbs/filters are clean,and the float height and float valves are good, then adjusting the screws should help. Or else you're getting bad info about the stock needle position/pilot jet size. But now it sounds like you may have a weak spark,which could make the plugs sooty also.

[frosty5011]

Yep Keith,

Forget to put in that last post that it is all 4 plugs that are fouling on me on the longer ride. As far as speed, I'm only going about 65 mph max right now - can't risk going more, as bike is not yet registered/insured.

I had also tried (before I noticed problem with condensers) adjust the screws more. I went as far as having Idle air out 2-3/4 turn, and the fuel pilot screws out only 1 turn. Was still rich in idle......that's when I decided to double-check the timing and came up with the above-mentioned condenser/points issue.

[frosty5011]

The black and white wires, coming from the points.......if I disconnect the "white" wire, then the points no longer show continuity when open. "Black" wire had no effect. This wire leads to the coil. I believe coil is OK (not 100% sure) and wire from coil goes to the kill switch.

When I put the kill switch on "OFF", the (after re-hooking up white wire at it's first bullet connecter, between points and coil), the points lose continuity when open (as they should). Jeez, I hate this electrical crap - not my specialty.

I assume this is not supposed to be the case, right? Defective/shorted out kill switch?

[Anonymous]

1. Do the bad condensers lead to the "grounding" of the points? I can put a lead from my continuity tester on each point, and get continuity reading, even when points are open and with a piece of cardboard between them.

2. Where does one get these condensers? Are they bought seperately, or do I need to get the whole "kit & kaboodle"? I see no marking on them, so I don't know if I could just get them at an automotive store...not know model # or specs. (OK, just found answer to part of this question. Cycle-Re-Cycle has condensers for 4.95/ea, and points for 6.95/ea).

3. Could this be what is leading to the constant rich fuel mixture?

4. What could lead to condensers going bad? Is it as a result of possible bad grounding somewhere, or a worse electrical problem? I had wondered why every once in a while I heard a "click" from the bike after a test ride. Sounded like it came from area of starter solenoid/battery box. Thought at first it was just part of the sounds engine makes when cooling...but was louder. Kind of like a spark plug "snap". Did it twice while sitting next to bike, setting the points gap.

1. Yes. But are you sure that your measurement is right? 4 Ohms looks very bad to me. Perhaps you should do a new measurement with disconnected coils and ignition off.

2. The condensers are standard automotive types (0.16-0.20 uF). You can get them at any bike or auto parts shop. You only need to find the right shape, or one that fits.

3. Perhaps. It would certainly influence the bikes performance. One of the symptoms is a mild "popping" sound when the engine is idling. The condensers are meant to reduce the spark over the breaker points, and give the coils a "sweep" of extra energy.

4. Condensers just get old. They start leaking and loose capacitance. Nothing unusual. You can tell when the condensers are bad, when the points start burning in unusually fast.
I'm sorry, but I have no explanation for the "clicking" sound. Could be the engine cooling down.

[Anonymous]

"I sounds like the left bank is running lean"

this is not a diagnosis, it is a quote from a movie.