66 Dream 305 Bogging Down

[Nick]

You sure you're operating the choke correctly?

The choke is OFF when the lever is pushed down.

If the jetting is stock (did you check it?) and the choke is in the proper position, about the only things that will cause excessive richness are an overly restrictive air cleaner or partially blocked baffles in the exhaust pipe.

If the bike sat for a long time, it's quite possible that insects may have built nests in the pipes.

Remove both baffles and see how it runs.

Remove float bowl and turn ON gas. You should have a good flow of fuel from the needle valve when the float is lowered. Dirt can build up between the brass seat for the needle valve and the carb. Remove needle valve seat to check this.

Did you check the timing with a strobe? If not, do so. That will tell you if the auto-advance unit is functioning properly.

Once you're certain that all the basics are correct (valves, timing, jetting, float level, etc.), if it runs rich, jet it leaner.

Buddy of mine went to test his half-miler just before a race, came back to the pits and complained to his mechanic that the bike fell on its face as soon as it came on the main jet, his mechanic didn't miss a beat: "Main jet prolly fell out." Sure enough, that was it.

[aburg]

Nick - you solved my problem (as embarrassed as I am) with this simple suggestion! I've been struggling with this for longer than I care to admit and I suspect the previous owner did as well since they showed me how they use the choke.

She has never run so well! Now I can actually tune the carb...

Thanks again... This IT guy who is usually the one pointing out the obvious just got a taste of my own medicine.

Aaron

You sure you're operating the choke correctly?

The choke is OFF when the lever is pushed down.

[LOUD MOUSE]

You may be right that it is rich if you smell gas.
One thing.
YOU CANNOT QUICK TWIST THE THROTTLE even at best tune.
Have you told us the jet size?
Have you checked with a timing light for how much the advance is?. ..............lm

lm - Thanks for your reply. I tried it last night and no change. If I rev it up slow, it will get rev up, but a quick twist of the throttle brings it on - the motor almost dies until I let up. Under load, it is the same thing - opening it up just bogs it down.

It smells like it is running rich when I do that so I feel it is more of a "too much fuel" issue than not enough air?

[DCheney]

I was reading this post, and I am dealing with the same issues of the bike bogging at higher throttle ranges, and it seems like too much fuel. I tried to read back, but couldn't quite figure out what the problem and more importantly the solution was...? PLEASE HELP, I have been dealing with this issue for a very long time, and this bike is so important to me, it was my grandfathers.

Thank you,
David

(903)269-8020

[Muddy]

I was reading this post, and I am dealing with the same issues of the bike bogging at higher throttle ranges, and it seems like too much fuel. I tried to read back, but couldn't quite figure out what the problem and more importantly the solution was...? PLEASE HELP, I have been dealing with this issue for a very long time, and this bike is so important to me, it was my grandfathers.

Thank you,
David

(903)269-8020

G'day David

It appears as though the solution was to operate the choke in the correct position. This forum has a lot of topics on the simple issue of operating the choke in the opposite way to that designed - it is a really easy mistake to make.

The bike should be run, once the engine is warmed, with the choke in the fully open position. This is achieved with the choke lever on the carb being in the fully down position.

To start the engine the choke needs to be closed, by raising the choke lever fully up.

Running the engine warm with the choke fully (or partially) closed will usually be really rich, resulting in black sooty fouling plugs.

Hope this helps.