Unusual engine running

[Bobbilljim]

 ??? 1984 Cal2 that sat for roughly 7-8 months without being run. Oil change plugs and wires, cleaned points with crocus cloth, gapped timed etc etc per the book. Carbs -PHF30 DD/DS, New seals, floats and needles (rh carb leaks b/c needle still not seating from possible float sticking) checked and double checked carb settings, throttle cable measurements. If I set the carbs to 1.5 turns out on the air and fuel mixtures per the owners manual, it starts and idles at 4000 rpm. I have to nearly back the air screws completely out to drop the idle. At which point I lean the mixture figuring I am too rich after closing off the slides. It's sluggish off idle, and I noticed with. Timing light on the timing is a bit jumpy. Already checked the chain tension and while not solid, shouldn't be loose enough to cause what I am seeing which looks to be 4-5 degrees erratic. When I adjust the light to 33 degree and throttle it up, the timing comes in pretty close for the advanced timing. Also, when I put a vacuum gage on the cylinders it flaps like a butterfly on speed. The only thing I haven't done is put new coils on it, new condensers, new points or done any valve work. I have no idea how many miles are on it. And lastly, please don't kick me out, it has hd sportster mufflers on it...

I am going to borrow a compression tester from a friend tomorrow and check that. I am guessing it needs points? How can I tell? Coils/condensers? (I have not measured for resistance)

What I would like to know, is, would it make sense to do one thing before or after another? As it would not make sense to change points and reset the timing if I were going to pull the timing chain later kind of thing.

Here are two of my you tube videos so you can hear what I am dealing with. I think the "runaway motor" is from the carbs not being perfectly synced but not sure.

http://youtu.be/GF8BHVA9vfE

http://youtu.be/KOTq1jAmyX4

Go easy on me....

[balvenie]

            Do you know its history, Rob? That is, did it always run so fast or is that since you had the carbs apart?

[rodekyll]

Symptoms caused by:

*chokes sticking
*cables sticking
bad cable routing
plugged idle jet
slides in backwards
*air leak
did you change the air filter?
*slides not seating
confusing the mix and air screws
using the cables to adjust the slides

Hmmm.  I think it might be carb related.  Check the marked items first.

[Kiwi_Roy]

It won't idle fast unless it gets a lot of air to run with, just saying.

[pehayes]

I would have first suggested the slides were in backwards.  But, those are round slide carbs and IIRC they have a locator pin and can't go in backwards.  Anyone correct me?

Patrick Hayes
Fremont CA

[Chuck in Indiana]

I've seen slides backwards, and it ran **really** rich. About like when I pulled a float bowl and found the idle jet laying in the bottom.  ;D
This is probably lean, most likely a vacuum leak, or maybe the slides aren't able to get back to idle for whatever reason.

[Charles in Lake Charles]

If the bike has many miles on it, switching the slides from one side to the other will result in a high idle since the idle screw is now resting on the notch which is not worn. Thus, the idle will be much higher.

[Bobbilljim]

More or less it has always run like this, but better now since redoing the carbs, putting new tomaselli throttle, new air filter and fine tuning the timing by lightbulb.

[Bobbilljim]

I would have first suggested the slides were in backwards.  But, those are round slide carbs and IIRC they have a locator pin and can't go in backwards.  Anyone correct me?

Patrick Hayes
Fremont CA

Correct, there is a tooth on the slide to prevent this.

[Bobbilljim]

 Have also sprayed the intake boots and flanges which did not affect the idle.

[kevdog3019]

The slides are bottomed out I presume?  What happens when you choke it at idle?

[guzzisteve]

I would see if the mixture screws are the long tipped screws.

They run about 3 turns out.

[Bobbilljim]

I always start with the air and mixture screws 1.5 turns out, if I went out 3 on the fuel it'd probably flood.

Not sure as I only hold idle open when it's cold until it warms up, but if I turn the choke off too soon it dies. The choke seems to operate pretty smoothly.

Pretty sure I didn't swap the slides as they have never been out at the same time. I do things one at a time.

It's sounds to me like you guys are pointing at the carbs..... Makes sense to me. I'm going to see if I can have a friend help sync the carbs. I have tried the hand over the  pipes method and the gage method. I haven't tried the two bottle method yet. I think I will try that one next.  The problem with the gage type is the needle is sweeping so fast back and forth I can't read it. I have a second gage that is liquid filled to keep the pulsations down but not the other gage. In case I have to do valve work has any one pulled a cylinder head?

[rodekyll]

The needle can be tamed somewhat with restrictors in the hoses.  Places like Motion Pro sells them, or you can find some little beads with the same size holes to shove into the lines.  It helps to use a tapered needle to set them such that the holes are clear.

I'm still thinking, that for lack of engine reaction to spraying the intake, that the slides are not bottoming out on the throttle stop screws.

Check for:

freeplay at cables (wiggle handle or tug on each cable to see if the sheath moves but the slides do not)
bad cable routing (turn bars lock-to-lock with fingers at slides to see if either one moves at any point in the travel)
binding/frayed/gummy cables (work the handle with fingers at slides and see if they *snap* down to their stops without dragging or hesitation.)

Did you change to lighter slide springs?


Also, measure the gap between the bottom of the slide and the venturri.  Use drill bits or allen wrenches to determine the amount they are open -- and if they are open the same amount.  Now count the number of turns out on the slide stop screws as you back them out to as far as the slides will drop.  You're counting turns to be able to return them to their original positions.  Still have throttle freeplay?  With the screws completely ineffective (backed out past contact with the slides) and freeplay on the cables, see what your idle is like.  I'd hope it has dropped too low to keep the engine running.

[Chuck in Indiana]

What RK sez. Aquarium needle valves can tame the bouncing needles, too.

[Bobbilljim]

What RK sez. Aquarium needle valves can tame the bouncing needles, too.

My fish tend to agree..... ha ha... Good point though...


Sorry, RK, please see my answers in your quote.... I tried to keep the answers near the questions. You are definitely asking the right questions. I just hope my answers help...

I'm still thinking, that for lack of engine reaction to spraying the intake, that the slides are not bottoming out on the throttle stop screws.



Check for:

freeplay at cables (wiggle handle or tug on each cable to see if the sheath moves but the slides do not)
-Yes...

bad cable routing (turn bars lock-to-lock with fingers at slides to see if either one moves at any point in the travel)
-No...

binding/frayed/gummy cables (work the handle with fingers at slides and see if they *snap* down to their stops without dragging or hesitation.)
-Snap....


Did you change to lighter slide springs?
-No, but not to say they weren't there already... How can I tell? Feels like normal throttle pull compared to a sportster I used to ride...


Also, measure the gap between the bottom of the slide and the venturri.  Use drill bits or allen wrenches to determine the amount they are open -- and if they are open the same amount.  Now count the number of turns out on the slide stop screws as you back them out to as far as the slides will drop.  You're counting turns to be able to return them to their original positions.  Still have throttle freeplay?  With the screws completely ineffective (backed out past contact with the slides) and freeplay on the cables, see what your idle is like.  I'd hope it has dropped too low to keep the engine running.
-Yes, it will die if I back them all the way out with the mixture screw (the recessed one near the filter side of carb) at 1.5 turns from "home". Also, when I do back them all the way out I do have slack in the throttle cables.

[rodekyll]

If your right arm is becoming overlarge after rides and it's hard to hold a full stein, you have the stock return springs.  If you still want to arm wrestle after a 500 mile day, you have light springs.  Sometimes the lighter springs don't give a good rebound, especially with old carbs.


That you can idle too low is good.  It's always better to start with the idle too low to keep the engine running and work up from there.

So now we need to start with the slide stop screws backed off, find the point of contact with the slide for each side, and use that point (look at where the screwdriver slot is) as your base index.  You can put a finger in the carb bore and feel the screw on the slide when it touches.

Crack the throttle a little so you don't run the screws into the side of the slides and start increasing the slide gap evenly side-to-side by 1/2-turn at a time until you can hold a low idle -- 600-ish rpm.  You will probably need to tweak the mix screws a little to coax it along.  If you get to a point where 1/2-turn passes the 600 mark, then get serious about the mix screws, trying to peak the idle and find that point where the engine feels 'right'.

Now check the dynamic timing and adjust as needed.  At 600 rpm there should be no advance active.  Don't worry about false blips on the timing light.  Just get the pots set to their timing marks.

Go back to the carbs and find the SMALLEST even slide gaps that hold you near your target idle rpm.  Tweak the mix screws to the least amount out that gives a good feel.  That means to peak the rpms using only one mix screw at a time, starting from turned too far in, winding it to too far out (idle peaks and drops) and then fish for that 1/8-turn of peak.  When you find it, set the screw for the closer end of the range.  Adjust final idle rpm with the slide stop screws.

recheck timing

check for cable freeplay

check for cables pulling evenly (fingers in the carb bores as you pull the handle -- tweak adjuster barrels till the pull simultaneously).
check for even slide openings at various points of throttle opening.  Just because it synchs at idle doesn't mean it synchs at 50% handle.

If you tweaked the cable adjusters, recheck freeplay.

That should do it.  Let us know what happens.

[Bobbilljim]

Hooray for lay mans terms! Thank you sir. May not be able to get to it til this weekend. That stupid thing called work.... I want to go out and fire it up right now but the neighbors may get a little bothered... :bike

Quick question, I'm am airplane guy, so we run a little on the rich side. Fuel I mean, not dollars... (Residual fuel assist in cylinder cooling) But when you say "1/8 turn of peak" I interpret that to mean that 1/8 area where idle falls off whichever side I turn, (stoichiometric) and it sounds like I should turn forwards the lean side and then set idle? Just want to be clear, not doubtful.

Thank you for taking the time to write all that out. I will definitely let you know what happens...

[rodekyll]

On aircraft we keep it a touch rich because we use fuel as a coolant to keep head and cyl temps down.  I could play the mix knob on my Cessna like a trombone and get radical temp differences.  The same thing is true for any aircooled engine, which is one reason why it's so hard to get aircooled mills to both run well and pass epa.  I was giving some general procedure stuff.  Just like 1-1/2 turns out on the mix is a starting point, ymmv.  If your bike runs better on the rich end of that 'fall off' then by all means dial it in there.  Just don't go out of the peak range to overcompensate for some other adjustment.

[Bobbilljim]

I have changed more than my share of cylinders of pilots thinking leaning is saving money. Yeah, until you need a top end.... Ok, I didn't know you were an airplane guy too!

So the sweet spot should be near that peak range on one side or the other, got it.

I borrowed that compression tester. The left cylinder was at 170 and the right was 150. I put a drop or two of oil in the right cylinder and got 170 the second time. Is that bad enough to do the rings on the right cylinder? I am actually pretty relieved. I was worried I might have a valve problem.

Hopefully I'll get to tuning tomorrow or Saturday.

Thanks again!

[rodekyll]

I'd say the compression is acceptable.  A 20# difference isn't a lot and there are a lot of natural reasons why one side might be a tad lower than the other.

Once you've got that sweet spot you might need to tweak it a little to get a smooth transition from idle to running jets, but that's a detail.  Right now we're just trying to tame the idle.

I'm a barstool pilot anymore.  I had my medical revoked some years back when I stupidly told the flight surgeon that I had seen a mental health professional after my divorce.  After several years of bitching at them they decided I could have it back.  By then I had no recency and I felt I needed to go through the classes again.  We lost our local instructor and I couldn't get back to the place in AZ where I had first trained, so I let it drop.  After this latest air disaster, the FAA has probably changed their mind about me again.   :P :'( :(   But I keep my hand in it as possible -- driving from the right seat, landing, etc.  I also had a minor role in reconstructing a 180 that had groundlooped.  We're adding a STOL kit right now before painting and reattaching the wings.  Hope to have it on the taxiway by the 4th of July.

[Bobbilljim]

What a tragedy. I don't get flight surgeons sometimes. My father in law had to fight for several years to get his back after a triple bypass. He is in better shape than I am and he is 75! At least you are still able to be apart of it. STOL on a 180, as if they needed LESS  runway to take off? Lol... You'll rotate at what, the end of the driveway? That's cool though. Post some pics!

[Bobbilljim]

Scary thought... I went out to check my coils as I realized I had not yet done this, and I found the primary windings on each coil around 4Ohms, the coil with the green wire showed around 10k ohms on the secondary but I couldn't get a reading on the red wire coil secondary. If I have a bad coil then that changes everything. My question is, last time I put a light on the timing, I was getting a light for that cylinder. I should probably replace it anyways. Any thoughts? ???

[Don Ivey]

Bosch "Blue" coils can be used in these bikes, and they make a big improvement over oem.  Also, you didn't mention
(or maybe I missed it) setting valve adjustment.  Just a thought.

[Charles in Lake Charles]

the coil with the green wire showed around 10k ohms on the secondary but I couldn't get a reading on the red wire coil secondary

Check the spark plug cap. NGK caps sometimes show an open circuit.

[Kiwi_Roy]

......the coil with the green wire showed around 10k ohms on the secondary but I couldn't get a reading on the red wire coil secondary. If I have a bad coil then that changes everything.......

Are you measuring with the HT lead in circuit, unscrew it and measure just the coil from the HT connection to one of the primary terminals.
My EV came with carbon core HT leads as well as resistor caps, one lead had quite a gap where it was arcing.
Consign the carbon core leads to the bin where they belong

[Bobbilljim]

Valves, yes, checked and set. Lol, about 30 times...

Measuring strait off the coil. Measuring the plug wires is a good idea anyways though.

I replaced the wires a while back and kept the original screw on plug caps. I seem to remember them testing proper. I'm not one to go on a "that's good enough" attitude. I try to get it within acceptable limits. That's why I'm here :) to get the "acceptable limits".

I appreciate all the input!

[Bobbilljim]

Update;
I got the cables routed so there aren't any sharp bends, I ordered a new set of elbow cable adjustments screws from MG. The ones I had didn't seem long enough and sure enough they were shorter than the ones I had. So now I am certain I have proper routing. The needle is set to the second notch in the carb, I unscrewed the slide stops all the way out and brought them in just as RK advised. I started trying to start the bike bringing them in 1/2 turn at a time with the fuel screws at the standard 1.5 turns out from stop. After a few goes of it, she started to rumble a few strokes before puttering out. Getting really close now. I also have a set of hose barbs screwed into the intakes going to a home made vaccuum setup. (Two bottles filled with colored water and a tube between them and a separate tube for each carb.) The bottles have stayed relatively equal throughout the process which gives me hope that syncing is not to far away. I have them up by the handle bars so when I take it out on the road I can get an idea of what she is doing "off idle". Alas, the battery finally gave out. It was a cheapo from amazon because I KNEW it would be used for mostly just cranking the motor over, getting recharged, cranking the motor, run for 10-15 minutes at idle while tweaking things and recharging. It was a $20 battery that lasted me 3+ years? So anyways, I am going to get a real battery now that I am close and continue the process. Thanks again for all the help. I will let you know how it goes once I get a new battery! ;-T

[balvenie]

   "what she is doing "'off idle'"

I would be afraid that if you opened the throttle too much, the engine would suck the fluid out of the bottles.

[Bobbilljim]

   "what she is doing "'off idle'"

I would be afraid that if you opened the throttle too much, the engine would suck the fluid out of the bottles.

Me too, so I made sure that if one bottle takes in all the water it cannot reach the tube at the top of the bottle to be injected into the intake. Each bottle is less than 1/3 full so if one bottle takes all the water it is only 2/3 full. It's not the qty of water that matters it's the movement.