Topic: Andys CB810 K2 -updated 14 Oct 2024 - missing link!

[chiefum]

The seat is looking good, and so does the bike!

[PeWe]

The old seat feels better on a longer ride, right?

I did a 210km ride today as most days the last weeks, bike feels a little bit too hard.
I got your post here about seat change on my mind and remembered that the rides became harder when my bike got a NOS K6 seat 2 years ago.

My old original seat I let a shop repair and modify in the 80's. Cutting it in a rounded shape, new foam under the cover was very comfortable.

I could ride my bike all day long on Autobahn in high speeds on that seat without butt complaints back in the 80's on several holidays.

I switched seats after the ride today.

[andy750]

PeWe so true. These aftermarket seats look ok and comfort wise they are ok but stock seat - cant beat it for comfort. The last time I had a K1 seat was on my K4 back in 2001 for the 16,000 mile ride to Mexico and back. Loved that seat (didnt lock) and it was pretty comfortable . Looking forward to some miles on the K1 seat this summer. K2 is riding very well after the Dyna S change.

cheers
Andy

[PeWe]

My hard seat I replaced is a real Honda stock seat, K3-K6.
I remember now (or my ass remember) why there were some aftermarket seats sold back in the old CB days.
King&Queen for those that liked long trips and did not mind the huge snail house look.

Easy to switch, the real seat can be used for shorter trips at special events.

[Johnie]

Glad you like the seat Andy! Better on your bike than sitting on my seat shelf   You are correct...the profile of the OEM seat is much better than the flat look of the repo seat. When I did my ruby red KO over 10 years ago I got my duckbill seat with the red foam from Yamiya. That was a good purchase. That Yami seat is so comfortable. Great looking bike Andy and nice job!

[andy750]

Thanks again Johnnie I wish I could buy all my OEM parts from you 

[andy750]

Checked my plugs today a few weeks after installing new DynaS and static timing. Not sure what to make of #3...replaced it and will check again after a good ride. Any comments on any of the plugs?





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[PeWe]

Hi Andy,
2 and 4 look OK for me based on top photo.
1 lean, 3 rich.
Air screws are equally set?
I have noticed they affect cruising speed around 100kmh (60mph).
Not much throttle when cruising  in that speed.
Getting there another thing, getting their quick needles and main jets.

The richest one enough if float overflow if close late or leak to make plug dirty.

The 2 vent tubes are not blocked or kinked?
And as usual, no air leaks.

[andy750]

Thanks Per as usual you have a lot of experience at this and good suggestions. The K2 (810cc) runs really well with a very steady idle (suggesting no air leaks) and very fast ramp up to speed with no hesitation. The only thing I was thinking of doing was replacing the baffles in 2/3 exhaust as they are older than the 1/4 baffles (HM300 exhaust). Ill need to check the vent hoses hadnt thought of that.
 
thanks
Andy

[PeWe]

I have spent many km the last year to find the correct carb settings.  4800km this year, rear tire was new when this season started.  Soon time to replace it.

Easier when ride often and change, see result and change quickly and another ride. Minimum 50km or 30miles since engine need to be really warm. Make notes is a must. Simple detail as an air/fuel screw  +/-  1/16 turn can make difference.

It will be interesting to see what needed to make all plugs to look OK, not too rich or not lean.
I jetted my carbs to give nice plugs, lost some power so I jetted for good dry idle, no sooting up after a few minutes at red light and good tesponse when twisting thanks to needle heights and main jet. Plugs are a little bit dark.
Good to see the ignition setting on the ground strap corner and not soot black porclain.

I verified ignition by reading the color at the strap. I had checked ignition and it was a little bit advanced. Plugs showed that.

https://www.crankshaftcoalition.com/wiki/Reading_spark_plugs

[andy750]

Thanks Per that was a really great link - I had been using the Haynes manual to read plugs but your link is way better! Sounds like I have some tweaking/test rides to do to try and get all plugs the same colour. Much appreciated.
Andy

[PeWe]

I like the ignition reading on ground strap.
That was more colored on NGK D8EA plugs than the Denso X24ES-U used now.

Read all 4 plugs now and then must be a must to see if anything is changed including the ignition marks at the corner.

[Stev-o]

Hey Andy....I'd be a little more concerned about #1, a lean condition can hurt motors.  Adjust it to give more fuel.

[PeWe]

Hey Andy....I'd be a little more concerned about #1, a lean condition can hurt motors.  Adjust it to give more fuel.

+3

[andy750]

Hey Andy....I'd be a little more concerned about #1, a lean condition can hurt motors.  Adjust it to give more fuel.

Thanks will do! This is exactly why I post appreciate the help.


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[andy750]

Ok after my last post I did check the air screws and backed them out 1 turn evenly across the carbs and this seems to have helped so far with plug colour though still in testing stage. Another problem has arisen...on start-up #1 header is cool to touch - other 3 pipes hot to touch. Here is what I have done so far:

1. Trimmed the HT lead - no effect
2. Swapped the spark plug cap between 1 and 4 - no effect
3. Changed spark plug to new D8EA - no effect
4. Checked the pilot jet and cleaned it out with brass wire (nothing was in there but cleaned it anyway) - no effect.

Once bike is warm it runs fine but clearly something is off. What else can I test? Bike ran great last year and only changes since then is new Dyna S but wouldnt off timing affect #4 as well? Cant see how this is Dyna S related - more likely fuel/pilot jet blocked....

Any other thoughts?
thanks
Andy

[Johnie]

Andy...I had that same issue with the 69 CB750K and it turned out to be a plugged hole at the very bottom of the carb #4. The only way to see it was to take the round tops off and look straight down the to the very bottom of the carb. This was plugged and I even had it cleaned via ultra sonic. I manually cleaned out that one hole and all was good from that point on. Sounds like you already checked over a the carbs, but had to let you know.

[PeWe]

Is that the needle jet, possible to take out thru the bottom plug?

Remove main jet and clean the tube, holes penetrated by thin wire.
Air vent a good idea to clean too, it should bubble in the float bowls when blowing thru the vent hose.

[andy750]

Thanks Johnie thats good to know its happened to someone else and you solved it! I figured it had to be a plug somewhere. Ill have a closer look and see if I cant figure it out.

Andy

[andy750]

Is that the needle jet, possible to take out thru the bottom plug?

Remove main jet and clean the tube, holes penetrated by thin wire.
Air vent a good idea to clean too, it should bubble in the float bowls when blowing thru the vent hose.

Yes i took out the main jet and cleaned through the holes with a brass wire. Clean! Really thought it would be that.

Air vent is air screws? Or do you mean the brass tube at bottom of carb cup?

Thanks Per,
Andy

[Johnie]

I couldn't find the pic Andy. The hole that was plugged was located under the slide where the needle jet would sit.

[PeWe]

Is that the needle jet, possible to take out thru the bottom plug?

Remove main jet and clean the tube, holes penetrated by thin wire.
Air vent a good idea to clean too, it should bubble in the float bowls when blowing thru the vent hose.

Yes i took out the main jet and cleaned through the holes with a brass wire. Clean! Really thought it would be that.

Air vent is air screws? Or do you mean the brass tube at bottom of carb cup?

Thanks Per,
Andy

Air vent is a small angled pipe, 2 vents with a long black hose.
One hose for carb 1-2, another for 3-4.

Same type as the overflow tubes, routed over air box

[andy750]

Ah got it thanks Per. Ill check it.

Thanks for looking Johnnie.

[MRieck]

 I have seldom found the problem(s) described to be ignition based. Crap in the carbs etc. Ethanol fuel really screws up theses old carbs too.......it is poison.

[PeWe]

You have extra dose of ethanol in USA too, 10%, right?
Here only beer dosage, 5%.

I have spent so much time adjusting my carbs so I hope they will stay clean and avoid dirty running engine destroying lean.

Shell V-Power has additives keeping it cleaner if I have not misunderstood. I have used Red Line SI-1 additive during winter just for sure.