engine bogs when "floored"

[sparkey]

on my gs750 it runs good and has ok power. when i hit the gas fast it bogs down for a second. but when i hit the gas a ltlle slower it is fine and takes off like a scared kitty cat! is this normal for these bikes?
carbs have been cleaned and bench aligned. i do not have a monometer to fine sync the carbs.

[Clone]

Airbox or pods....

[sparkey]

i take it it is not normal? everything is stock. airbox and exhaust. the main jets have 102 on them stock should be 100. the carbs are not original but came from the same year.

[Nessism]

Where are the fuel and air screws set?

[Big T]

At what rpm are you finding that this happens?

[sparkey]

the idle screws are 1.5 and the bottom screws are .5 turns.
it doesnt happen at an "rpm" it does it when i spin the throttle from nothing to full throttle quickly. when i spin the throttle slowly i dont notice it.

[Nessism]

There are no idle screws, just pilot fuel screws and pilot air screws.

I suggest opening up the fuel screws to 7/8 and see if the problem goes away.

[sparkey]

thanks Ed,
will try it in the morning. I was thinkin about that just needed a kick in the pants i guess.

[Steve]

It sounds like you are snapping the throttle open rather quickly.

In that case, yes, it's "normal".

That is why the EPA encouraged development of the CV-type carbs that would prevent that "bogging".

.

[sparkey]

thanks guys, i turned out fuel screws and resealed the air cleaner its more betterer now..

[OldVet66]

No matter how well tuned, VM's will bog if you snap the throttle wide opened in too high a gear. With higher RPM they respond nicely when kicked it in the pants.

[Big T]

If you want to crack it wide open, make sure you're up in the 3-4K rpm first

[sparkey]

Now after a shake down ride it stalls sometimes when coming up to a light. I wonder if i turned them too far out. maybe its a little too rich now. its gettin late so i'll have to try some stuff tomorrow. thanks guys..

[chuck hahn]

Check the big idle knob adjuster between 2 and 3 carbs..got it so it idles around 1000 to 1200 RPM?? Also go to BIKECLIFFS WEBSITE and choose the 750 ( 8 valve ) service manual download. The 102 main is fine. The default setting for the clip on the needle jet is the center groove. The pilot screw on the botom goes 1 turn out from bottom. the air screw on the side is at 1 1/2 turns out. These are the basics so it will run settings according to the manual. From there yo should then vacuum sync the carbs. Then begin the process of fine tuning the carbs. There are certain things that MUST be right before youll get it to run right. !st is a proper valve adjustment. 2nd is the carbs being vacuum synced. Then and only then will any adjustments you do really mean anything. It makes no sense to get it running on whatever the valves and carb sync is and then do the maintenace and turn around and have to do the carbs again. Do yourself a big favor and back up the train and be sure the valves are done right, then set up the carbs..

[sparkey]

The gas cap was not venting for starters, so after clearing that up I did the coil mod. No more stalling.
Oh and the previous owner had the valves adjusted. It does have a new valve cover gasket so I kind of believe him...