sync - anger...and hate..... NEW PROBLEM

Ok so i guess i'm paying for how easy it was to bleed my brakes yesterday today....

I just tried to sync the ( female dog ) and i just can't understand wtf is going on....

First of all

# 3 only pulls like 4 in Hg vac

the adjustment screw for 2 also adjusts the idle screw lever.... WTF?

the vacuum gage i have i tried to reduce it and put a fuel filter on it but the bloody needle still bounces all over the place.... so i kinked the hose slowly until it read a vacuum level...


the only thing i'm impressed with is how much this bike wants to run. cause i adjusted stuff all over the place and she still runs....



I don't want to have to rip the carbs off again...


hate this sync crap....


GRRRRRRRRRR

 

Re: sync - anger..... and hate.....

first- what kind of bike again? please update your sig with the details. it will help us to help you down the road.

second, the idle screw will adjust all carbs together. it is connected to 3 and the carbs all adjust off of 3.

third- if you are only pulling 4in of vac, you either have 3 other carbs that are absolutely way off on sync, or you have a vac leak on 3. if there is no leak, that means that 3 is barely open and the other 3 are compensating for it.
try to adjust 4 so it is very close to 3, then turn the idle up a bit so 3 will pull its own weight. From there, you can try to get 1 and 2 working together then 2 and 3.

if they still will not set, you have a vac leak in the system.

 

Re: sync - anger..... and hate.....

also, reset your idle screws to 2.5 turns out.
reset as much to base as possible and work from there.

 

Re: sync - anger..... and hate.....

Last week I had to pull the carbs AGAIN to adjust a float height (some how I missed one of the carbs and it was way to high). I decided to bench sync them. I tried to use the sewing needle/paper clip trick (sewing needle is more accurate and more uniform in size), but I decided that the FEEL method was not that accurate due to the callus on my fingertip from toying with this bike. So I tried this, I put a needle under the #1 & #2 butterfly at the very bottom. Then I tilted the carb rack forward so that when I slowly opened the butterfly's the needle would fall out. I then adjusted the sync screw between them till the needles would fall at the EXACTLY the same time. Then I repeated that for the #3 & #4 carbs. And then again for the #2 & #3 carbs. Then for the icing on the cake I put a needle in all for carbs, slowly open the butterfly's, wala all for needles fell out at the EXACTLY same time. And I do mean EXACTLY. Put the carbs on, blanked the YICS, BAM all four carbs pulling the same mercury, EXACTLY. Being a humble guy for the most part, I even impressed my self.

 

Re: sync - anger..... and hate.....

As you adjust 1, 2, and 4 to where they need to be, #3 will come up. You will need to adjust the idle adjuster under the carbs to compensate.
Adjusting #2 drags #1 along with it, and can adjust your overall idle, as you are adjusting 2 carbs at the same time.

Forget the "regular" method for right now, since #3 is "low" , adjust the highest carbs lower, then sync normally. Every minor adjustment in the right direction will get the whole motor running better and better.

You do know that a "low" reading means that carb is working harder, and a "high" reading means that carb is barely helping out??

 

Re: sync - anger..... and hate.....

Sorry Hemet, but a carb that is closed pulls a strong vac.
A single carb wide open would show little vac.

Razz1969- - I think you are on to something new here !!
Possibly a more accurate bench sync method.

 

Re: sync - anger..... and hate.....

in my head, I was thinking it was the opposite, but I just convinced myself that it was reversed from what it really is.
my bad

 

Re: sync - anger..... and hate.....

Here's some General Notes on One Gauge Syncing that might be helpful.

If you have Air Leaks at the Manifold to Head mating surface, ... you won't pull much of a Vacuum and Syncing the Carbs is futile.

1, 2 & 4 Have Sync Screws
1 & 2 are Married. Adjusting 2 automatically adjusts 1.

If you tested for leaks and found none.
Test Compression.

The single vac gauge will fluctuate with the Manifold
Where the needle rises farthest is the Vacuum pulled.
MARK the face of the Gauge with a China Marker at the High Point.

The Adjustment Screw for 2 Does NOT adjust the Idle Lever ...
It adjusts BOTH >1 & >2 Because 1 & 2 are Married.

 

Re: sync - anger..... and hate.....

Thanks Time To Ride

 

Re: sync - anger..... and hate.....

thanks going to pull the carbs again right now and then bench sync again...



do i want the butterflies clear of the little hole on the top.... or just closed?

 

Re: sync - anger..... and hate.....

The service manual says use the thinnest feeler gauge- - 0.0015
so that's pretty well closed.
I have good results using 2 layers of printer paper, cut into feeler gauge-looking strips. The 2 layers measure 0.010 or so.
I adjust until the "drag feel" feels the same on all 4.

That's the method I'm comfortable with.

 

Re: sync - anger..... and hate.....

Take a business card and cut it ito 1/4" wide strips and use the strips like a feeler gauge. Rick suggests this method and I use it all the time. Works great.

Go to your local Torpical fish/Aquarium store and get some plastic valves they use to adjust air flow to the filters and such. They work well to dampen your vacuum gauge.


MN

 

Re: sync - anger..... and hate.....

just did a fast bench sync didn't do the pilot screws just the butterflies....

bike runs great i know i still need to sync them....

NEW PROBLEM THOUGH....

What would cause the rpms to race with the clutch in?

we are talking like 2 to 3 g's of rpm in first gear when the clutch is in?

 

sorry my bad....

it's the idle speed creeping up which is the same problem the PO was having....


I think there is most likely a vacuum leak somewhere....


gonna try and find it tomorrow...

also she seems to be running hot....

Should she be hot to the hands on the fins?


smells a little of burning oil too.... but that could be from the oil i spilled on her a long time ago when checking the valves...

 

Close the Throttles.
Back-off on the Throttle Cable Tension Adjustment until you have 1.5mm Free Play in the Throttle Grip.

Secure the Throttle Cable Sheath to the Center Frame Rail in two places with Duct Tape.
Make sure the Throttle Cable Sheath cant move if the Clutch Cable is Tensioned or the Steering moved lock-to-lock.

 

I don't think that's the problem....

Throttle cable is fine. I'd say it's perfect!

 

RickCoMatic,
Thanks for the details on the screws.