Bike is sluggish all of a sudden

[Guest]

Afternoon,

After a full carb clean and sync the bike had been running great, I took it out last Thursday and noticed it seemed a little sluggish, did not have the throttle response I had been used to. Thought maybe it was just from sitting for a week and a half.

But I went out yesterday and when I started her the choke was different. Usually I only needed it about halfway out and it would fore right up and within a few seconds the rpms would climb. We'll now it needs to be the whole way out and doesn't seem to effect the rpms

Any thoughts as to what this could be?

I checked all the hoses and boots they all appeared to be 8j decent shape

[tom203]

"Usually I only needed it about halfway out and it would fore right up and within a few seconds the rpms would climb"

^this is normal

"We'll now it needs to be the whole way out and doesn't seem to effect the rpms "

^this is not normal, so make sure "choke" linkage is actually working at carb end - maybe a bracket loosened up and plungers are not fully pulling out.

[60ratrod]

did you do the carb cleaning as per the ever famous tutorial? if so, then have you checked that you are getting spark on all 4 cylinders?

if not, then check the plug caps, wires, and coil resistance, both on the primary and secondary sides. if all of those check good, then cut 1/4" off the end of the wires to get to the fresher wire before sticking the plug caps back on, now check the voltage that you are getting to the coils.

first check to see what your battery is producing with the key off, then with the key on so you have a base line to go off of. with the key and kill switches in the "on" position, check the voltage you are getting at the switched voltage side of the coil, or the orange/white wire. if you are not getting what the battery is producing within about .3-.5 volts, you have what is becoming a more common problem with these aging electrical systems. if it's more than .5 of a volt, but not much over a full volt, you might be able to get away with just cleaning all of the electrical contacts with some electrical contact cleaner, like de-oxit. if it's well past a volt, you might get away with the contact cleaning, but more than likely you are going to have to do the ever popular relay mod.

now if you are getting close to what the battery is producing with the key and kill switches on, have you checked and adjusted the valves? improperly adjusted valves will drag down engine power, increase time it takes to start, and increase felt vibrations.

valves good? well maybe there is a killer after you.......

[Slycox]

As far as the plunger it appears to to be in good working order.

Yes it was tore down per the tutorials here and dipped. New orings from Robert barr and all that.

I'll check the electrical side soon

Pulled the plugs and all appeared to be running. 12&4 were dark. So I adjusted the mixture screw, seemed to help some. I'll do some more tuning and another carb sync.

[Nessism]

How long since your last valve adjustment?

Other than valves the petcock could be faulty, or low voltage at the coils, dirty air filter, old plugs, etc.

[Slycox]

How long since your last valve adjustment?

Other than valves the petcock could be faulty, or low voltage at the coils, dirty air filter, old plugs, etc.

Did shims about 1000 miles ago. Plugs and petcock new last year about 1600 miles ago. I'll check the air filter and voltage.