Carburetor Frustration

[eleven_special]

I spent the day removing my carburators on my 1981 SH and disassembled them and cleaned them.I found them to be long overdue for cleaning and the main jets were slightly corroded.I polished things up the best I could and reassembled and reinstalled them.Sadly I found the bike to be working much as it had been.It will start OK,it runs rough as it always has until warmed up.Then it smoothes out and while sitting will rev up impressively and generally feels good.When I get on the road under very light acceleration it works OK.When I open the throttle
it bogs down and if sputters a bit,this happens only under heavy acceleration.Obviously I missed the point while cleaning them.Does anyone have any ideas on what my next step should be? Eleven_Special

[Firehawk]

I had this same problem for a bit. My carburetors were clean and in good working condition, and yet I couldn't open the throttle.

You're too lean.

If you haven't done anything to the stock setup, you might be sucking in extra air somewhere. Maybe in the airbox, maybe in the boots. You'd hear an exhaust leak, so I doubt it's there.

That's what I'd look for. Spray carb cleaner around the airbox boots, and the manifold boots and see if there's a change in your rpms.

[randy]

Have you checked the operation of your vacuum advance mechanism? May not have been your carbs all along.

[eleven_special]

Needle Jets

Might it be possible that dirty needle jets could let me rev to my hearts content at a standstill but cause bogging under heavy acceleration?Also are after market jet/carb kits available for the XS?

[TopCatGr58]

Oh boy,

A bunch of things you need to check out! First, are you sure you're hitting on all four? Spritz the pipes with water to ensure they are all sizzling! These machines can spin easily in neutral, but under load, if not hitting on all cylinders can be a bear.

Secondly, as mentioned, verify your vacuum advance module is working, and that the vacuum hose is attached to the proper place, the outlet on the #2 carb BODY, not the Intake Manifold!

Also, did you pull out the vacuum slides, and inspect the rubber tops for pinholes? Verify that they slide easily up and down, and then push them up all the way, put your finger/thumb over the arced port on top, the slide should not slide down much if at all. IF it slides down quickly, you've got holes in your rubber diaphragms.

Also, check to make sure you're getting fuel to the carbs. Check out your Octopus, they can go bad and stop or slow down their flow! Have you checked your air filter lately? IF running stock setup, make sure your snorkel under the seat isn't kinked or clogged with animals or debris!

Report back with findings and we'll continue this process!
T.C.

[eleven_special]

Check List

Thank you all for your kind replies.I am running stock set up even stock 4-in-2 exhaust(albeit newer slip ons.All is as it has been for ten years of owenership.Air filter good.All four pipes hot.Same amount of fuel in each bowl.Slides working well.Fuel octopus OK as checked by by passing with prime setting.Checked petcocks and fuel filters.Read plugs and found number two sooty,others light tan on tip?Have yet to check vacuum advance,sounds very interesting as it can be a bit erratic in its derelection of duties.Only sometimes appearing to starve on idle.Failure to pull on acceleration possibly improved marginally on repeated roadtests.Special Note:Bike has not been running in two years.

[pggg]

es, if you can, unscrew the idle mix screws a few turns, and also sync the carbs with gauges or suchlike. Fuelbowl floats need to be exact. Also take the bike for a LONG 7000 - 8000 rev blast to blow out cobwebs. You'll want the motor so hot it's creaking.

[LoserShoes]

Try it with the gas cap open to rule out the gas cap vent.

Steve