Topic: Way high RPM after carbs rebuild

[firebane]

@ 15deg past TDC
-undo the lock nut
-back out the retaining bolt so the cam chain plunger is free
-snug the retaining bolt back in to lock the plunger back in place.
-tighten down the lock nut.
done.


If the cam chain tensioner has never been serviced, it might be best to take out the three bolts, pull out the unit, and clean/grease it well.
Look for a depression in the plunger rod, and fix as necessary.
The plunger should move freely in the tensioner.  Old grease there can prevent it from 'tensioning' the cam chain as the plunger spring is kinda weak. 

550s don't have a means like the 750s for the tensioner as it is all one piece.

[flybox1]

^^ my mistake   
Carry on.

[Can550]

^^ my mistake   
Carry on.

So what I have done is right and fine ?


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[firebane]

^^ my mistake   
Carry on.

So what I have done is right and fine ?


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Once you have loosened the nut the tensioner should self adjust then just retighten. Some people have found that they still need to do a small adjustment when the bike is running.

[TwoTired]

The tensioner unit has a spring to position the tensioner when the lock nut is released.  It is supposed to take up the tension automatically when the lock nut is released.  If done regularly, you won't notice much movement in the stud.

However, to make sure the stud is free to move, after I loosen the lock nut about 1/16 inch.  I tap the screw end of the bolt to push it in a little.  This forcefully releases clamp pressure in the internal slider.  Then, if you want you can engage the screwdriver slot and and turn it (counter clockwise, I think) against the spring.  It will snap back and your tensioner is now tensioned.  Lock down the nut, but don't strip that bolt.
Of course, you do have to position the cam for 15 degrees to get the slack side of the chain on the tensioner side beforehand.

Cheers,

[Can550]

Thanks TwoTied
Any thoughts on vacuum sync gauges I posted (from Amazon)?


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[TwoTired]

They look similar to what I bought in 1975.  But, I got a cardboard case instead of a plastic case. 
I did get connecting hose with mine, though.

Go to the aquarium supply and get a gang valve with five nipples.  You will use this to ensure each dial reads the same from a common vacuum source.

Vacuum line you get from auto parts stores.

Cheers,

[Can550]

Sorry but if you are asking about flaps (butterfly looking plates) or the main plate on which all four carbs attach?

I'm not certain if flap/ plates were removed.


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Looking at airbox side of your carbs there are little adjustment screws and tabs for each of the butterfly valves. If this are not seated correctly they will fight against one another and not function properly. Using a screwdriver to work them is also very bad and could cause twisting or bending of parts which should not.

And yes you should adjust the valves, tensioner then do a sync because all the internal mechanicals have to be functioning together to run properly and if they are not the synch process will not be accurate.

Sorted sticky/ hard, choke lever

Once tank was removed for valve adjustment, I had a closer look and could feel where the resistance was. In following photo, (first plate on the left of screw) there is marking left by the ball or pin I dropped couple of WD40 drops and it started moving pretty easy. Once it rest on normal position, a pin (I assume spring loaded) holds on to it as there's a hole to ensure it does not travel/ move to choke the air.

Thanks everyone for suggesting various remedies. I was really not looking forward to removing carbs to check what is preventing free movement


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[Can550]

So I adjusted the valves, cam chain tensioner and ignition timing. Placed the tank back on and fired her up.

Fired up fine but was vibrating quite a bit. I don't hear cam chain sound neither do I hear tappet sound but left lower pipe (cylinder 1 I guess) was popping. Then I noticed gas puddle on the floor, overflow tube/s draining gas.

Air/ fuel mixture screw is 1&1/2 turn out

Vibration seems to go away after 2500 RPMs
(Yet to vacuum sync carbs) hoping to get it to right point where only syncing is left.


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[Stev-o]

Not sure what your issue is, but the sound of your bike made me cringe.

Listen to what it should sound like at idle....

[not mine]

[seanbarney41]

Spank those float bowls with a screwdrivr handle or something...it will often unstick your float.  You may have only been running on 3 cylinders due to flooding.

[enwri]

So I adjusted the valves, cam chain tensioner and ignition timing. Placed the tank back on and fired her up.

Fired up fine but was vibrating quite a bit. I don't hear cam chain sound neither do I hear tappet sound but left lower pipe (cylinder 1 I guess) was popping. Then I noticed gas puddle on the floor, overflow tube/s draining gas.

Air/ fuel mixture screw is 1&1/2 turn out

Vibration seems to go away after 2500 RPMs
(Yet to vacuum sync carbs) hoping to get it to right point where only syncing is left.


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I just watched the video on the link above, at .25 speed on the playback settings, from 17 seconds in, have a look at the points and points cam.
Is that some camera effect? or is it the points spindle bent or not seated properly?
That points cam looks to be bouncing around like there aren't any main bearings in that motor.

[Can550]

I'll check in the daylight but it may be due to flashlight on camera, shadow or something but thanks for noticing and pointing out


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[Oddjob]

If your looking for a decent set of vac gauges then buy a set that resemble the genuine Honda gauges, I worked at a main dealers for Honda, Yam And Suzuki and we had 3 different sets of vac gauges, no one used the Suzuki ones, rarely used the Yam one although you needed to for 6 cylinder engines as the Honda ones only had 4 gauges and the Yam had a selector knob which went to 6, the Honda ones were the most used and by most, I mean virtually every time. They are not pre-damped, they have small knurled knobs just under the gauges, meaning you can just twist gently and the needle on the gauge would stop oscillating, most aftermarket gauges don't have this and they suffer as a result, either the needles don't move fast enough or they bounce all over the place, don't get ones that use what are essentially aquarium air line clamps, like these http://www.ebay.co.uk/itm/Vacuum-Gauge-Carburettor-Carb-Balancer-2-4-Cylinder-Motorcycle-Car-Engine-VGA4-/182352071209?epid=1571642454&hash=item2a7507ca29:g:QccAAOSwXeJYJ5JT those are rubbish, get ones like this http://www.ebay.co.uk/itm/LAST-FEW-4-GAUGE-ADVANCED-MOTORCYCLE-CARBURETTOR-BALANCER-TOOL-SET-VACUUM-/181607421453?epid=711165413&hash=item2a48a5560d:g:uUUAAOSwkNZUhwzn you can see the damper knobs are like the genuine Honda ones. You pay more but you get what you pay for. There are sellers in the USA that sell them like that, you just need to search.

[Can550]

Thanks Oddjob
Very limited options here in Canada. Getting from USA or Europe makes shipping+custom+tax and handling, very expensive.



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[TwoTired]

Well not bad for an engine only running on three at best.

The overflow is likely flooding out at least one cylinder.  Flash touch the headers to find the cool, non-firing cylinder.  And then focus on it's corresponding carb.

Really not much point in a vacuum sync until you fix the carb issue.  Rapping on the carb might help the float valve to seat.

Have you done the static points gap and timing, yet?

Cheers,

[Oddjob]

http://www.ebay.ca/itm/Closeout-ABN-Carburetor-Synchronizer-and-Adjustment-Tool-Kit-Gs-Kz-550-650-750-/332137548009?hash=item4d54f0c8e9:g:zPwAAOSwx6pYsI6Z&vxp=mtr those are on Canadian E-Bay. Not exactly the same as Honda ones but should be ok. Or these http://www.ebay.ca/itm/Fuel-Pressure-Carburetor-Vacuum-Synchronizer-Carb-Sync-Gauges-CB-KZ-550-750-650-/152499500966?hash=item2381adb7a6:g:7b8AAOSww3tY5YCG

[firebane]

http://www.ebay.ca/itm/Closeout-ABN-Carburetor-Synchronizer-and-Adjustment-Tool-Kit-Gs-Kz-550-650-750-/332137548009?hash=item4d54f0c8e9:g:zPwAAOSwx6pYsI6Z&vxp=mtr those are on Canadian E-Bay. Not exactly the same as Honda ones but should be ok. Or these http://www.ebay.ca/itm/Fuel-Pressure-Carburetor-Vacuum-Synchronizer-Carb-Sync-Gauges-CB-KZ-550-750-650-/152499500966?hash=item2381adb7a6:g:7b8AAOSww3tY5YCG

First is $80 for just the product and then $70 for shipping for a total of $150 CAD 

They would be better off calling a shop and asking to see if he can borrow if they will do it as it will cost the same.

[flybox1]

http://www.ebay.ca/itm/Closeout-ABN-Carburetor-Synchronizer-and-Adjustment-Tool-Kit-Gs-Kz-550-650-750-/332137548009?hash=item4d54f0c8e9:g:zPwAAOSwx6pYsI6Z&vxp=mtr those are on Canadian E-Bay. Not exactly the same as Honda ones but should be ok. Or these http://www.ebay.ca/itm/Fuel-Pressure-Carburetor-Vacuum-Synchronizer-Carb-Sync-Gauges-CB-KZ-550-750-650-/152499500966?hash=item2381adb7a6:g:7b8AAOSww3tY5YCG

First is $80 for just the product and then $70 for shipping for a total of $150 CAD 

They would be better off calling a shop and asking to see if he can borrow if they will do it as it will cost the same.

$110 CDN....free shipping.

https://www.amazon.ca/AlphaMoto-Carburetor-Synchronizer-Gauge-Vacuum/dp/B01KEOHRB6/ref=sr_1_fkmr2_2?ie=UTF8&qid=1499780304&sr=8-2-fkmr2&keywords=carb+vacuum+gauge+set

[firebane]

http://www.ebay.ca/itm/Closeout-ABN-Carburetor-Synchronizer-and-Adjustment-Tool-Kit-Gs-Kz-550-650-750-/332137548009?hash=item4d54f0c8e9:g:zPwAAOSwx6pYsI6Z&vxp=mtr those are on Canadian E-Bay. Not exactly the same as Honda ones but should be ok. Or these http://www.ebay.ca/itm/Fuel-Pressure-Carburetor-Vacuum-Synchronizer-Carb-Sync-Gauges-CB-KZ-550-750-650-/152499500966?hash=item2381adb7a6:g:7b8AAOSww3tY5YCG

First is $80 for just the product and then $70 for shipping for a total of $150 CAD 

They would be better off calling a shop and asking to see if he can borrow if they will do it as it will cost the same.

$110 CDN....free shipping.

https://www.amazon.ca/AlphaMoto-Carburetor-Synchronizer-Gauge-Vacuum/dp/B01KEOHRB6/ref=sr_1_fkmr2_2?ie=UTF8&qid=1499780304&sr=8-2-fkmr2&keywords=carb+vacuum+gauge+set

Good deal!

Added to my wish list.

[Can550]

Well not bad for an engine only running on three at best.

The overflow is likely flooding out at least one cylinder.  Flash touch the headers to find the cool, non-firing cylinder.  And then focus on it's corresponding carb.

Really not much point in a vacuum sync until you fix the carb issue.  Rapping on the carb might help the float valve to seat.

Have you done the static points gap and timing, yet?

Cheers,

Yes TwoTired I did flash touch all four headers and none was cold to be non firing. Thought cylinder 1,2 pipes had stronger exhaust pressure (at the end pipes) than 3,4.

I did tap on all four carb/ bowls to release any stuck float but to no avail.

I had adjusted valves, cam chain tension and timing. Tester light lights up respectively on F1-4 and F2-3.

Next I'm going to remove drain tubes, place a tray/ dish under bowls to see which one or more than one is draining gas.

Is it advised to remove bowls while carbs are still in bike?

Cheers


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[Can550]

I went ahead, pulled all the drain tubes out of the frame (left them connected to bowl) dropped ends in a container, turned the petcock ON, within seconds # 4 started to drain. Tapped on bowl but made no difference.


Removed bowl #4 carefully. It is very clean, float movement (up and down) is not restricted in any manner.

Raised the float and left a plastic part under it to support staying up, turned gas ON for few minutes and it didn't leak at all.

Now looking at bowl, found that (guy who rebuilt my carbs) a round O ring was used instead of a house plate shaped. Further, O ring seems little larger than needed, assuming excess was getting inside and preventing float movement.

Now off to hydraulic supplies to get smaller O ring.

At this point in time, wish someone knows exact size so I don't have to try/ experiment fitment.

Cheers


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[flybox1]

BunaN or Viton only.  All other o-ring material will swell when in contact with gas.
You can buy gaskets that fit the shape of the bowl, so there's no fooking around.

http://4into1.com/shaped-o-ring-float-bowl-gaskets-4-pack-honda-cb350k-cl350-cb500-cb550/

[Can550]

Thanks
Did want to get from them but shipping and custom works out to over 75$ in addition to cost of stuff ;(


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[Oddjob]

Don't buy the Amazon gauges, you'll regret it if you do as those are the type you don't want, aquarium clamps instead of proper damping wheels.