Tell me if I'm on the right track [VID ADDED]

So I've got my plugs a real nice brown at idle. When I roll on the throttle very slowly, either to take off or just on the center stand in neutral, it bogs out like its choking itself, then clears up and goes fine. It always runs fine off idle.

If it sits on the center stand, warmed up and idling, it will sound real nice for about 20 seconds, then stumble a little, recover for another 20 seconds, stumble again.

I'm thinking its acting like floats too high, but they check ok.

Thoughts?

 

Re: Tell me if I'm on the right track

Additional info:

When I sync the carbs, if I get all 4 even at idle, then roll on the throttle, #2 and 3 will lose vac before 1 and 4 do.

I set it this morning, so that they aren't even at idle but ARE even just off idle. It seems to take off better, but I'll have to give it a ride to work and back to know for sure if its an improvement. It seemed better just around town here at least.

 

Re: Tell me if I'm on the right track

Did you replace the throttle shaft seals?

(I'm assuming your valves are in spec.)

 

Re: Tell me if I'm on the right track

Yes and yes Fitz. It was better than yesterday coming into work (lots of stops) Still a little finicky when taking off, but much better.

I know I won't get it perfect as the carb bodies are worn, but i'd like to get it.. "not annoying" till I get the green light for a new bike. (In like 5-10 years).

 

Re: Tell me if I'm on the right track

It's still a little stumblish, BUT only when it's warm, when it's cold it responds nice to throttle, i'll have to check the plugs this morning and see if she's rich on a couple jugs.

I'll report back tonight

 

Re: Tell me if I'm on the right track

Any chance you're running pods?

Or are you using a stock airbox? Do you have a clean air filter?

dave F

 

Re: Tell me if I'm on the right track

Try richening up ONLY 2 and 3 just a hair. (When the bike is fully warmed up, your inner two cylinders are running slightly hotter than the outer two.)

 

Re: Tell me if I'm on the right track

Stock airbox, air filter is still white, I leaned out 2-4 this morning, and it's a touch better. #1 is the worn carb so it doesn't like adjustment from where it is.

I will try some more adjusts like you suggest Fitz on the weekend, i'll report what I find here

 

Re: Tell me if I'm on the right track

Current colour of the plugs
http://db.tt/TvKyHaBM

That is 1-4 left to right

 

Re: Tell me if I'm on the right track

SO close.

#1 is just a tippy-tad rich, #2 is fine, #3 is "fatter" than 1, and #4 is fine.

And ignoring the insulators and JUST reading flame rings and ground straps, only #3 is still a hair rich. If #1 is fussy just leave it be and lean up 3 just a hair and see where you're at.

Once the plugs all come back even, have a quick look at your vacuum sync. It may need re-touching. You are blocking YICS for the sync, right?

As for the occasional stumble, have you attended to the spark plug caps, as in spun them off, lopped off a bit of wire then reattached them, and made sure all resistor cores are snug?

 

Re: Tell me if I'm on the right track

Yep, plug wires have been checked. I find I get a better sync not blocking YICS, I've done it both ways a few times, and when using the Block tool, I always get a crap sync after removing the tool and replacing the bolts.

I WILL try it one more time syncing WITH the tool tho, just for ghits and siggles

Thanks for your input Fitz!

 

Re: Tell me if I'm on the right track

If you get "A better Sync" sans the YICS Tool, ...

You might have AIR "sneaking-in" at where the Intake Manifold -to- Head mate.

Attempting to tighten the Manifolds presents a DANGER of Snapping a Manifold Cap Screw.
That will create a NIGHTMARE!!!

If you suspect the Manifolds are allowing Air to enter the Plant where the Manifolds and Head mate ... You can:

Remove Carbs.
SEAL the Joints.
SMOOSH* some RTV into the Seam where the Manifold and Head mate.
Masking the Outboard duo with Vinyl Electric Tape will give the job a professional look when the tape is removed before the RTV cures.

*smoosh (smoush)
tr.v. smooshed, smoosh·ing, smoosh·es Informal
To squash or mash.

 

Re: Tell me if I'm on the right track

I guess that could be a possibility, last time i did a vac leak test nothing turned up, but that was a couple years ago, and i've never taken the intakes off.

It would be good to take a closer look at them tho, thanks Rick!

 

Re: Tell me if I'm on the right track

I have a YICS tool............somewhere. Still in the plastic. It's nice to show it at a carb clinic now and then so people know what everyone else is talking about. LOL

Smoosh.............common term in my vicinity. Not to be confused with Shmooze...........another very common term-------

Dave F

 

Re: Tell me if I'm on the right track

You can EXPERIMENT taking the Intakes off.
If the Cap Screw doesn't come loose, ... abandon removal.

Those Cap Screws are CHEAP SOFT STEEL.
Break one off and the Head comes off and needs a Machinist to remove the remnant.

Where the Intake mates to the Head there is an O-ring type Seal.
They get old, dried and flattened out.

The RTV Trick works well.
Slim Coffee Stir-sticks make a good Tool for Smooshing.

DONT GET C0CKY and muscle those Cap Screws.
They ACT like they are TURNING.
Inn reality, ... they're TWISTING.

Snap one and the Clock starts ticking on "Down-time".

Its better to have to RTV the joint several times ...
than too break a Manifold Bolt ... once.

 

Re: Tell me if I'm on the right track [VIDEO ADDED]

I've carefully tried to get those intake bolts out once already. I'm pretty sure they'll break, I stopped real quick the first time I tried (i knew they could be broken easily)

So here's a vid after the sync I did last night. This was with the resting state after using YICS block etc etc. The sync actually stayed pretty much the same, yics or no yics this time.

You'll notice #2-3 fluctuating quite a bit. You may be able to hear (not on headphones) the engine rpm change when they go down.

https://www.youtube.com/watch?v=sjvtZy6cCGQ

I was totally wrong on my cmHg lol it's looking ok.