Topic: K2 stutter

[AJK]

Hi 7fifty4,

Your carb settings are pretty much exactly what i am running, except that i am at 7/8 out on the mixture screw.

Just some random thoughts, as kghost has mentioned, your float levels have to be right, otherwise, nothing else in your carb will work in a calibrated way.

You should be getting some colour out of your plugs with those settings. Are they all coming out white or just one or two that you are checking? I'm wondering if you have air leaks, leaning out the mixture, or fuel starvation.

If your carbs are clean and carb boots are airtight & you are sure your fuel is flowing ok, then you might be suffering from weak spark at that point.

Another important & overlooked point can be old plug caps. Try starting your bike up at night, giving it a rev and seeing if you can see spark leaking at the caps. This happened on mine causing missing, and new caps fixed it.

Check also that your rubber trumpets are sealing on the rear end of your carbs. Mine worked a little loose and made funny pulsing sounds which didn't really affect performance, but made a bit of noise.

Check your spark gap as well, if your running points, set the plugs to the stock gap which is 0.6-0.7mm. With your dwell, err towards greater dwell by setting your points gap to ~0.012" rather than ~0.016". This should see better spark as well. I run an electronic ignition, but did this when i was on points.
  Check electrical connections blue/yellow wires for good connectivity and all grounding for your ignition.

Also, don't rule out bad condensers if you haven't changed them.

I have never measured fuel rate, but if your petcock and screen are clean & you are running stock honda fuel lines or equivalent (5.5mm internal diameter??) and they are clean, then your flow should be fine.
  When was the last time you cleaned the petcock screen?

[krusty]

This bike has done 92000klm, right? Perhaps your needles and needle jet are worn. On reading through this post a few days ago I don't recall you having replaced them or did I miss it?

[7fifty4]

okay here are the things I have done, so far - not in any particular order -
new
 spark plugs
 coils  -  leads and caps
 points
 head was done - valves ground, pressure tested, etc, all good
 Carbs, dissasembled, ultrasonic cleaned by myself and reassembled with all new (Keyster - I heard now that some Keyster rebuild kits aren that good -*sigh*)
     needles jets , the   lot - needles are in 3rd from top - (middle position)
 tank cap
 petcock

float level adjusted to 26mm - still want and need to check with clear tubing method
running 98 octane fuel - consider changing this to 91 unleaded

I am awaiting new TEC condensors - hope they will come this week

#AJK - yes all plugs are white as white
         -  I am trying to find the original fuel hoses, I have currently after market 1/4" (inside) on there

   fuel rate - I am getting about 550ml fuel in 1 minute and 10 seconds out of the two barbs on the ( new ) petcock, it made no diff whether I had the petrol cap open or shut
      - asking whether anyone knows what that actually should be. And I am getting a different flow out of the two barbs

cheers

[kghost]

They do flow differently.....it just follows the path of least resistance.

I've never measured the flow rate....but as long as its a steady stream and not dribbling out....its ok.

On the subject of Octane......91 in Oz is 87 octane in the US.

Same stuff different measurement. Oz is RON (research octane number) US is AKI (anti Knock index, the average of the Research and the motor octane number.)

There has been a bit of debate about the keyster kits. Centered around the needle taper.

I personally measured Keyster vs stock Keihin. Using a drill gauge I compared various aftermarket needles to the stockers. Some were different. Meaning they had a different taper from the stock.

Maybe you have a set of keysters with the taper off.

[seanbarney41]

do the clear tube float bowl check already.

[7fifty4]

I try the clear tube test tonite - despite the heat - its killing me to know where it will be.
One question to that - where should the petrol be stopping in the clear tube - say what, about 10 to 15mm below the gasket - more, less? I start searching the forum now - will place it here if I find something - thank you

Edit: - I found two numbers on a thread
here is the link: http://forums.sohc4.net/index.php?topic=110715.0
here is one quote from the thread:  " ... 26mm float measurement using traditional method corresponds to a fuel level 4mm below the top surface of the bowl
(I believe HondaMan noted this?)"
The other number a bit further down the same thread is 5mm




The needle taper - would yamiya, davidsilver, or any other supplier anyone knows, actually still have originals (Keihin) I would then order? Or  - do you have the measurement what the taper should be and I could measure the ones I put in? that would be great.

And one more thing about the fuel flow - it is bizarre to watch - I removed the two hoses from the two barbs and opened the tap - and it does flow out of one outlet and it has not the same flow on the other    -  I had the petrol Cap open ! - then I closed the tap - to do another measurement -  re-open the tap and... the other outlet now had the more steady stream coming out and the other did not had a steady flow All this with a brandnew petcock.   - - compared with one other guy measuring it, I have half of his flow going.
as mentioned below.
Bizarre ? could there be some dirt in the tank ?? -  I have to check it out -

thank you for explaining the RON and octane  - very helpful indeed.

cheers

[kghost]

Nah mate that's how they flow. Path of least resistance. I wouldn't sweat the petcock.

I did not actually make any notes on the difference.

What I did is started in one of the smallest holes and measured the remaining needle.

There was a difference in the middle. This would sort of equate to about 1/2 throttle position.

The difference between 4 and 5 mm on the clear tube method to my thinking is negligible.

Split the difference at 4.5?

[7fifty4]

okay  - no worries - I leave the petcock alone - for now
Just coming back to the inside, I have made a clear tube fitting now  and have to wait 24 hours for JB weld to cure - *sigh*

I also made some pictures of the spark plugs  -  as per request.
These plugs are new ones and used only once - with these (current) settings -  unfortunately one non working condensor too, I found out after the run.
so here are the settings:
26mm float height - to be measured and confirmed - (tomoro?)
needles are all at 3rd from top
timing done, the two indicators are between the one extrusion - I used a timing light...
new points are set at 0.35mm
stock standard 4in4 exhaust, baffles in
new coils, leads and spark plug caps
new #110 main jets
new #40 idle(?) jets
Air screw turned out 1 and 1/2 turns

dont think I forgot a setting ...?

cheers

[AJK]

My opinion is that they look a little on the lean side but not too bad. #2 & #3 look to be more in the ball park than #1 & #4. The ground strap shifts colour about half way which is a good sign. There is no evidence of aluminium on the porcelain so thats also good.

Your probably not that far off but could do with a bit more enriching. Dont forget that plugs only give you an average colour unless you are doing a plug chop for a specific range.

If your clip is in the middle position as you have mentioned, then I probably wouldn't touch it, but i would definitily double check your float levels with the clear tube method to make sure the floats are spot on. *Everything* depends on the float level being right. If its not, then all 3 carb circuits pilot,needle and main will not function as intended.

If your float levels are all ok, try going 1 clip position richer (position 4 from the top), raising it one notch.

What Dave says about the washing machine is true. The carb still looks at the average level though, even though its like a choppy day at the beach inside. So float level is important.

You can actually do them on the bike. I've mentioned it here
http://forums.sohc4.net/index.php?topic=95994.msg1476704#msg1476704

also, here is another good link

http://www.salocal.com/sohc/tech/carb/asmpg_mgs/flthgt.htm

Also, do you have any fuel inline filters in between the petcock and carbs? If so, get rid of them. You mentioned you have a new petcock, so your screen will be clean then, so thats good.

Also, Ace's suggestion of going to 115's might work for you as well. Try getting the float levels right first though.

cheers

[jonda500]

Quote: "Bizarre was that the fuel came out of the two brass connections on the tap in different flow rates and every measurement I took it came out in a different flow form a different connection. Different in a way that one had a strong flow and one was trickeling - that surely can not be right... or is it?"
This is perfectly normal -if you block one brass tube the flow comes out the other one, block the other one n it'll come out the first one again.
It is my understanding that the plugs when removed after a period of normal use (riding mainly with the throttle between 1/4 and 3/4 open) will reflect the richness or leanness of the mixture which is controlled by the needle clip position. My plugs were very white despite having D8EA plugs instead of the standard D7EA and I saw a big improvement by inserting with shims under the needle clips to make it 1/2 a step richer...
edit: oops sorry I was on page one still

[7fifty4]

Hi - -

I did make the "clear tube level check" last night and found that the levels are not at a level between 4 to 5mm. I am trying now
to think of a way to confirm the 4 to 5mm measurement. I triple checked the 26mm float level and they seem okay.

Once I have done the above and I have hopefully got my new condensors by then (I know now that one of them is faulty), put different fuel in the tank,
 I start at 95 octane, if I can find some here.

If I should have any more issues after that I plan on doing a plug chop.

I keep you posted - in the meantime I'd like to thank you all for your input and patience so far.

cheers

[mutters]

mate ,
 what sort of air filter are you using ?.
Those clean looking plugs look like its lean still
could it be getting heaps of air ? like high flow type filters.


cheers Jeff

[7fifty4]

mate,
stock standard air box - stock standard airfilter element(new one too)

I just came in from shed - took off carbies, to double triple checked the floats, they were all on 26mm (close enough to).
Then put the carbies back on and checked them with the clear tube
#1 - about 6mm - left it
#2 - was 12mm, adjusted it to about 5mm
#3 - was 14mm - adjusted to about 5mm -  but is now overflowing out of the bowl, not out of the seal!
#4 - was 10mm - adjusted to about 5mm -
should they all be around the same? strange...

Now the big question, right?, - to go back to the 26mm float level or leave the levels as adjusted - just have to get #3 to about 7mm to make it stop leak.

And yes, they are 0657 carbies by the way, and I do not have any inline fuel filter.

Edit - I attach some pix - for the carbies and all were adjusted to what the pictures show -  26mm. might not show up properly - but then, put the carbies back on and did the clear tube check and they were out by a bit. As
you read above.

[AJK]

Hi 750/4,

#3 sounds weird. That sounds like the float valve is not closing on the seat. The overflow sticks out above the top of the bowl by about 3mm to 4mm, so if fuels overflowing out of that, check for a sticky valve on #3. It shouldn't normally do that.

Now that your've got the clear tube setup, stick with that method as its the most accurate. Just adjust all the carbs so they are level. Based on your readings, it show that the 26mm method is only rough & doesn't show up other problems like leaking floats & differences from carb to carb.

On this link http://forums.sohc4.net/index.php?topic=110715.0
people have mentioned that they set it to 4mm (i beleive this is what Hondaman does). I'll have to find this.

Try and aim for 4mm if you can, but if they are close enough to 6mm & you can't be bothered mucking with it anymore, take it out for a run and see how it goes. I've just checked the fuel level (stained mark) on an old fuel bowl here and its 6mm, so your probably in the ballpark. Try and aim for 4mm if you can.

Again, check for sticky float valve on #3.

I'm going to redo mine on the weekend as I have my #4 plug coming out a bit darker than the rest. Will let you know how i go.

PS: Here are a few more related links (to drive you mad) 
http://forums.sohc4.net/index.php?topic=70987.0;all
http://forums.sohc4.net/index.php?topic=81874.0
http://forums.sohc4.net/index.php?topic=5410.0

[Ace]

You are having trouble aren't you. Are the bottom of each of the floats both level? If one is bent up it will put off your measurements as one side will say 26mm and the other maybe 24mm etc. The tab in the middle between floats the needle sits on is where to adjust. You can measure and adjust float height with the carbys on the bike, if you have a light hand you can feel the needle seating and then measure. Just be sure you don't push too hard and depress the end of the needle.

Can you move the floats freely? Not getting caught up on the posts where the float pin goes through?

If one is leaking out of the top of the gasket, then lower the float height by 1mm. Maybe gasket not seating with bowl on, pinched gasket?

[7fifty4]

you guys are very helpful - I was ready last night to throw in the towel - its getting to me now 
thanks for all your support - I am ready to get the sledge hammer out - well last night at midnight - 4.5 hours after doubting my eyes and all I've done so far...
thanks for the links they certainly gonna make me mad - I havent looked yet....

planning on more things on the weekend - I wish the new condensors be here now - seems like they're in a canoe or something....

Edit: I checked some of the threads out and I found some of them before, but still, when I get to say this one

                   http://forums.sohc4.net/index.php?topic=81874.0

it has some pictures attached, but they appear only as a white canvas - even when I am logged in - how do I get to the pictures? Does anyone know ?


Edit#2 [forgot to answer your questions - sorry late night]: all float valves and all jets etc etc, are new (Keyster repair kit); all floats are moving freely; I'll check #3 again tonite, gasket and all;

wishing you all the luck, if needed, on the weekend AJK !!

[krusty]

Maybe its better if you step back for while and take  deep breath. Wait for the condensers and just think things over.

[AJK]

+1 with Krusty. Put it aside. You'll feel better after a beer or 3 tonight, then recollect your thoughts over the coming days. This is all part of the joy and frustrations of 'enjoying' your bike, but take courage, its all worth it. Patience wins in the end.

Your definitely in the wrong season to be doing this by the way.... 

[7fifty4]

hi all -

had a few coldies whilst waiting for the condensers, and to calm down....

 finally they arrived and installed them, (finally), adjusted as good as I could all carbies to the 4.5mm float setting ( cleartube level) and cleaned the tank, put in 91 octane unleaded - with some additive  -
I took it for a 100Km ride today and .... almost perfect.... !!!! can not believe it - its 95% there  - from what I can gather and a look at all the spark plugs told me -  - okay 100Km, may be not a very good distance to judge, fair enough. I still feel that it is missing some fuel, the plugs look "brownish" , #2 and #4 are black, #1 and #3 look brownish, but dry. I can not post the photos at the moment, but will try to get to a pc with the " right stuff", if there is still some interest from you guys.

Thank you all for all your help, assistance and words of wisdom, appreciated.

hooray - Broadford looks very possible ...

[Terry in Australia]

Well done mate, and if the gods are smiling, I'll see you at Broadford! Cheers, Terry.

[7fifty4]

Thanks, appreciated. Took longer than I thought, never mind, almost there.
You're right, if the gods are smiling and I can find the solution to my doubled fuel consumption. Its now using 10L/ 100KM ( 22Miles per gallon? ). ouch.
Before the rebuild it used about 5L/100Km - ( 45MpG ? ) - and hope to get the jets and timing sorted by then, obviously some things are not quite right yet.

cheers

[AJK]

Glad to see you getting sorted. Just for reference (on average riding - both street and highway), i'm getting 46 MPG (USA gallon)

[7fifty4]

Hi AJK - thanks and thanks for the data, good to know, I am trying now to get it sorted to get back to the old mark of 5L/100Km, for sure.
cheers

[Ace]

I'm averaging 34 MPG. Few mods since I last measured so it will be interesting to see.  All I have to do now is find the time to ride.

[7fifty4]

Thanks Ace - would be really good to know if you get to a different result now. Would you don't mind posting it, once you know?