Carby choke cable

Discussion in '2-Stroke Engines' started by wrightmor, Oct 20, 2013.

  1. wrightmor

    wrightmor Member

    Just started riding bike again after 3 year storage. Had to replace throttle. Bike runs really great. Nice smooth ride. Pulls hills well. Speed OK. My question is this. To have the aforementioned ride, I have to have the choke cable fully engaged. When I stop I have to disengage choke to keep engine running. Something tells me that in spite of smooth ride, I shouldn't have to be using choke this way. My guess is I need to adjust gas/air mixture on carb. But bike is riding so good, I didn't want to touch anything til I heard something from you guys. Will it hurt to keep using it as it is? Sure don't want to mess up my engine. In case you haven't guessed, I'm really not much of mechanic, but am learning a lot just playing with bike and reading these forums. I did do search prior to posting this. Didn't see any similar questions. Forgive me if I missed it.

  2. lazylightning@mail.r

    lazylightning@mail.r Active Member

    Methinks you have an air leak at the mainifold. Probably you dont have the rubber o-ring in the carb where the mainfold goes in and or dont have any high temp silicone sealant on the surfaces. It could be the manifold to cylinder suface, but just tightening it should be okay if there is a gasket in there.
    No, you shouldn't be using the choke to drive with. It has an airleak. No matter how lean you got that stock carb tuned, it cant be that lean from the lean-rich needle setting. That more or less controls the ratio at idle range. Even a miserably lean (small hole) jet from the factory couldn't make it so lean that you can't drive without the choke....
    Last edited: Oct 21, 2013
  3. lazylightning@mail.r

    lazylightning@mail.r Active Member

    Is your carb mounted level?
  4. wrightmor

    wrightmor Member

    carb is almost level. Keep in mind, I had almost a year of good riiding (no choke) before my move here. You may be on to something with air leak. Sorry, just don't know what manifold is... embarrassing. but i can slip my whole carb off the motor with just a twist and a slight pull. I can twist carb at anytime. bolt holding carb on can hardly be tightned anymore. Maybe couple of washers would help? have no rubber O ring, but a hard plastic looking ring around the throat of carb. Can I paint this with permatex and solve anything?
  5. Uncle B

    Uncle B New Member

    I saw in your other thread that you moved, did you change elevation? You may need to rejet it.
  6. HeadSmess

    HeadSmess Well-Known Member

    did you drain the carb 3 years ago before putting it into storage?

    me thinks a tear down, soak in some nasty stuff overnight, and a thorough removal of all gum deposits from the jet would cure it...

    permatex/silicon the carb on, fo sure! they gotta be tight!

    otherwise...what engine? it has a choke cable...unusual around here...

    check plug condition.

    research what a manifold is.
  7. wrightmor

    wrightmor Member

    My bike motor is Gruber Skyhawk with 66cc. Not been able to work on it much this week. Speaking of storage, not totally accurate. I have tried to make it perform during the summer months, but that entailed riding with screwdriver in my pocket to adjust carb idle screw and mixture screw. Neither adjustment seemed to make difference. I pushed bike almost as much as I rode it. When I replaced the throttle, it runs like new with the choke cable engaged. Not enjoyed bike like this since right after I did the install. I want to attach pics of the choke cable and carb. Chokeswitch on handlebar actually has the word 'shift' on it making me think, maybe OK to ride as is. But I plan to do check for those air leaks as soon as weather let's up here. Thanks for all the great inputs.
  8. Big Red

    Big Red Active Member

    If the carb is loose enough to just wiggle it off, then it's WAY TOO LOOSE, And you for sure have an air leak. the intake manifold is the thing yer carb fits on. this has to be tight and pushed all the way up, sometimes you ca get bt without a O-ring, But it's not recommended. The EASY way to check for an air leak is to carefully drizzle water on both intake connections while the bike is running. if there's a leak the engine will slow or stall. It's a cheap, easy, FREE test. I've been doing it this way for years. Some will say to use WD 40 or some other chemical, BUT, WATER IS FREE, Do this test AFTER you think you have it sealed.
    I would NEVER pay this much for one, but Heres what it looks like
    And then the O-ring
    wrightmor likes this.
  9. wrightmor

    wrightmor Member

    There is in the 'throat' of carb that slides over the intake manifold a filler type material that takes up gap between carb and neck of manifold. It looks to be cylinder type filler about half inch long and is tight in carb. I will have to get my O ring or washer past this in order to seat it in place in carb. May be able to fold O ring and push it thru to desired location. Haven't seen the washer (if I decide to go that option). But it prob will not be as flexible. Can this little filler (someone may want to give me right name of this item) be removed and reinstalled with no damage? It is tight. How do I get it out without messing it up. Cud I push the O ring thru without even disturbing this thing that I am calling the filler?
  10. lazylightning@mail.r

    lazylightning@mail.r Active Member

    I think you have a "sleeve" inside of the carb throat. It fit's onto the manifold tube end. I just pushed the little rubber o-ring in there. The rubber 0-ring should be 19 mm wide, which is the same width as your manifold tube end. So you shouldn't really have to fold it. Its okay to bend a rubber o ring though. Use some high temperature silicone gasket sealant too. Tighten it up, almost all the way, but not all the way. Wait a day for it to dry and then finish tightening it.
  11. wrightmor

    wrightmor Member

    well, i got the 19 mm washer and it was too large. It rode right over the top of the manifold tube, not resting in the place it was supposed to butting the manifold to the carb. I already had the carb off. So I proceeded to remove the sleeve and then the existing washer. Looks like it was worn somewhat but still looked serviceable. So (though I would have preferred new washer), I loaded the washer on both sides with the heat resistant sealant and put it back in place. Then I put a washer at the bolt that tightens the carb around the manifold to try and get it tighter. Almost stripped out the head of the phillips head on this bolt trying to get it tight. no avail. it was still loose. So I took it back off, removed the sleeve and put a little cardbord strip around the sleeve and like to never got it back in the carb throat. When I tightened it down as tight as I could get it, I very gingerly turned or started to turn the carb and it's still loose. Come to think of it, it has never been super tight. Did not try to ride today. will let the sealant dry. Also applied heavy thourough coat on the exterior of carb where the washer is almost visible from the top of carb. I hate i can't get it tighter. Think it will ride ok if the old washer will serve along with the sealant. Will test it tomorrow.
  12. wrightmor

    wrightmor Member

    UPDATE: My carb is lots tighter, though I think I still might could pull it off if I tried. Think the sealant helped a lot with that. Also, got better idle than I had before, but I worked with the idle on the carb to get it. I did get a water sprayer and sprayed at both ends of the manifold and at top of carb with no difference in idle. No stall, nor even threat. I took it on the road and the ride is the same. When I hit around 20 mph the throttle is of no more use to me. When I engage the choke (alloy shift) the bike picks up again and I can go 30-35 mph with no problems.
    One of you suggested setting the jet (sorry, i'm on page 2 and don't want to lose what I've started to find name). I did this earlier (last year) before I replaced the throttle with no marked difference. Should I go back and reset the jet or does the problem sound like it might be resolved with such action? I do have just a little bit (not enough to get excited about) of smoke out of exhaust when it idles. Will resetting the mixture screw on carb help? With the water test behind me, I really am begining to think it's something other than air leak. What harm might I do to ride it as it is? I travelled 14 miles round trip couple weeks ago in this fashion with no negative results... yet.
  13. lazylightning@mail.r

    lazylightning@mail.r Active Member

    I would guess that you helped it by sealing the connection. Obviously so if it idles better. Now what about htis carb you have? What kind is it? Does it really have a mixture screw? Obviously it is not a stock Chinese motor carb if it has a choke cable. How did you adjust the jet before?
    wrightmor likes this.
  14. wrightmor

    wrightmor Member

    It came with the engine. It is featured on this webpage:

    full carb picture, very similar, if not same carb:

    yes, i have a mixture screw and an idle screw. I adjusted idle this time by stopping bike, disengaging clutch with throttle engaged just enough to keep it running. Then I raced the engine and held it steady while adjusting the idle screw. If engine went louder, I let off on throttle to see what I had without it's help. Eventually I got pretty good idle speed. Messed with mix screw just a little, but didn't want to mess up what I had.

    I adjusted the jet before by taking off the top of carb where the cables enter. Then took off the little C clamp washer and moved it up or down (don't remember) to the next available setting and put carb back together. found helpful utube video to guide me thru this. I read or heard somewhere that this might help with the changed altitude or elevation here in TN over what I had in FL.

    engine is 66 cc Skyhawk, if that is any help.

    Wouldn't the fact that I have to feed the engine via the choke to relieve the sluggish throttle indicate a lean mixture setting somewhere? Maybe I should adjust the C clip on the slider needle toward a richer mixture? Just a stab in dark from rank amateur at this. Tried again today to adjust screw on carb and lost my idle again. I can fix that but still have to deal with the rearing back of throttle.
    Last edited: Nov 1, 2013