Engine bog has me boggled

Pic of the plugs?
Steve

SWest wrote: Pic of the plugs?
Steve

Hi SWest,
The plugs are brand new.
When I set the floats and checked the carb again for blockage, the rich running was gone. The plugs were turning to a good tan color. When the bogging got worse I thought it was starving for fuel due to float level so I went back in and reset the floats a little richer. All that did was make my plugs black again and the bog was still there.

I can get a pic tomorrow but I don't think this is the issue.
I have never experienced this gag to acceleration like this before which is why I am suspecting the Dyna.

Could be the coils. Does it only happen when it gets hot?
Steve

SWest wrote: Could be the coils. Does it only happen when it gets hot?
Steve

I replaced the original coils with Dyna coils, still had rough running, Went to the carbs for the rough running issue.
Bogs hot or cold.

A trick I use is to run the engine up and down while looking at a timing light. If it's electrical you should see it unless the plugs are fouling at that speed. TTYL
Steve

SWest wrote: A trick I use is to run the engine up and down while looking at a timing light. If it's electrical you should see it unless the plugs are fouling at that speed. TTYL
Steve

excellent trick, thank you!

Ronnie_D wrote: I have a Dyna DS2-1 self contained ignition system. Pretty slim on the availability of troubleshooting guides . I am tempted to buy an new one from Z1E and see how it goes, but that would be a 200 dollar guessing game. The bike sat in storage without a points cover for years, Also the bike was dumped on this side as I can see road rash on the muffler pipe and rear brake lever and it was missing the points cover. Maybe this thing is done for. I can't see what else it would be but this. The symptom is weird and like nothing I have seen before, which is why I am suspect of the pickups. It runs beautiful up to 3000 rpm or so but when you apply more throttle to go the whole engine goes blah, no stumble just a gag effect.

bizzare.

any thoughts?

cheers,
Ron

Have you checked your ignition advancer?


.

Ronnie_D wrote: The book says between 0.05 and 0.10 mm, is this for intake and exhaust?
.

The book is out of date and they are the old clearances which were revised upwards .
Regardless of your bogging problem your 0.7mm and 0.8mm clearances are too tight.
Clearances need to be between 0.10mm and 0.15mm on all valves .
0.10mm is minimum and anything below needs a thinner shim fitted .
It's best to aim for the upper figure of 0.15mm .

Ronnie_D wrote:

slmjim+Z1BEBE wrote: What is voltage at the coil primaries vs. battery voltage? Voltage drop across the ignition switch can be significant.


Good Ridin'
slmjim & Z1BEBE

the voltage was 11.6v at the coils and 12.8 at the battery.

That's a little more than 10% voltage drop. Likely slightly higher percentage with the motor running, when voltage at the battery should be around 14v. or more. A direct primary connection to the battery that mimics the bypass relay mod might tell the tale.

Can you measure resistance in ohms across the Dyna pickups? Resistance should be as close to zero as possible, just like if points were closed. Elevated resistance across the pickups will reduce the resulting secondary voltage just as surely as voltage drop across the ignition switch.

As the throttle is opened combustion chamber pressure rises, and voltage needed to jump the plug gap increases as well. If secondary coil voltage is compromised because of low primary voltage that might cause the symptoms described.

EDIT : Also agree with Nebr_Rex - check the advancer by watching the timing marks under a timing light as RPM increases from idle.


Good Ridin'
slmjim & Z1BEBE

[/quote]

Have you checked your ignition advancer?


.[/quote]

yes, I cleaned,lubed and tested the advance unit. I set my timing with a timing light and the advance is working properly.

thanks.

the voltage was 11.6v at the coils and 12.8 at the battery.

1.2 volts is excessive voltage drop. Should be less than .5. Hot wire the coils with a jumper straight from the battery and see if that corrects the problem.

VTEC wrote: 1.2 volts is excessive voltage drop. Should be less than .5. Hot wire the coils with a jumper straight from the battery and see if that corrects the problem.

I will try this hot wire today.

thank you.