Engine bogs down when using to much throttle

Discussion in 'Norm's 2 stroke repair center' started by ChuckL333, May 11, 2012.

  1. ChuckL333

    ChuckL333 New Member

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    Hey, to start this off I want to inform everyone that I've gotten this build used, and since have taken it down for a complete rebuild changing every single cheap bolt these kits tend to come with. I've run into nothing but issues such as bolts snapping off in engines, causing the engine to bounce and snap the chain slicing my tire while doing 30+ odd MPH. When I first got the bike, I was able to run at full throttle without an issue. Now, when running the bike the engine bogs down at anything over 80% throttle. This started happening before I took everything apart however.

    Now.. the only thing that I can think of is the gas I'm using. When I got it, I instantly thought to gas it up with some 50:1 that I use for most of my other equipment. From what I believe, that's when the issue starting happening. I haven't tried to run another but the 50:1, but now the tank is just about empty its time to refuel. Before I go and do so, could it be the 50:1 gas/oil mix making my engine die at to high of a throttle? I've adjusted the needle pin to every slot and the highest setting works the best.
     
  2. tooljunkie

    tooljunkie Member

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    most of the stuff i have is 50:1 mix.
    i prefer to run 40:1 when using conventional oil.
    i do run opti-2 in my bike occasionally,but its jetted a little rich.
    i dont think the bikes care for 50:1,i have read 32 or 40:1.
    do a search on "plug chop" and follow the instructions,this will give you insight on whether its rich or lean.
     
  3. 2door

    2door Moderator
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    Chuck,
    Check your messages. I just sent you a PM. Hope it helps a little but also listen to Tooljunkie's advice. He repeated essentially what I said in the PM but offered some additional information for you. Good luck.
    Tom
     
  4. tooljunkie

    tooljunkie Member

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    also,almost every seller of these offshore engines has a downloadable manual on their sites,in threads even here on this site.
    if you havent already,you migt want to give it a skimming over.

    Frank
     
  5. ChuckL333

    ChuckL333 New Member

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    Well.. now I'm having more issues. My bike now 4 strokes bad through the whole RPM range, from low to high. And I mean BAD... I can get about 15 MPH our of it, but that's really pushing. When I get going to fast, it just seems to drown itself, and after a few seconds it's back to four stroking. I'm really tired of dealing with the POS carb on this thing, I've adjusted every single thing I can besides the jet, something I don't really feel like doing as I'd have to order new jets (no experience or any idea where to get the bits to fill/re-drill)

    Would getting a whole new carb from a different company be a good idea and solve a lot of headaches? Maybe buy a set of jets to go along with it.. I got a old schwin springer that is just aching to do 30-35MPH!

    I've noticed that I seem to have a ton of oil build-up on my muffler and on my frame, by where the muffler connects to the head. I know I need to fix this with a new gasket, but could that be the real reason why I'm four stroking? On another note, when I hold the gas with the clutch in, even trying to keep it as steady as possible the RPM's bounce up and down a good amount without increasing/decreasing the clutch amount. It idles perfect.

    Edit: P.S. Running 50:1, this engine seems to really HATE it. I've switched to 32:1 and now the oil build up has been getting worse. Spark plug checked, it looks perfect, same color as milk chocolate!
     
  6. tooljunkie

    tooljunkie Member

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    well,i have a feeling its getting a little too much fuel.
    the carb is very simple,a couple screws to remove the bowl and the jet is right there.
    i soldered my jet shut with a propane torch and acid core solder.a drop of flux and i was good to drill.a set of the teeny drills was 4.50 at our local discount parts store.i had a tip drill (pin vise) for my oxy/acetelyne so i used it to hold the bit.you could use a vise grip and put the jet in a cordless drill and carefully drill it out.very slow and light pressure.
    remember to use the drills to measure and record the original jet size.
    you may discover the jet or the tube it mounts to is loose,sucking too much fuel.

    does the carb leak gas after its parked?
    i leave the petcock open if i suspect a dirty needle and seat,it will overflow carb.it doesent take long to see fuel dripping.
    dirty air filter will make it rich also.

    exhaust maybe plugged and need to be cleaned,i have used carb cleaner to loosen the gunk and then blow it out.
    you mentioned needing to change the gasket anyway,two things get done.


    also dirty fuel bowl could indicate a dirty needle and seat.

    if i could find a tuneable carb i would change mine too,i would rather change a screw adjustment over re-jetting any day.
     
  7. ChuckL333

    ChuckL333 New Member

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    I work at a hardware store and have done so for about a year, and this is just something I've never dealt with. I'm slowly coming to learn that the more I just suck it up and do stuff on my own, the faster a learn so I might have a go on re-jetting everything myself. The store I work at is old fashioned and we have all the tools setup for me to do so without any charge or purchase for bits/torch plus we've got a vice open to us and all customers. I'll check the air filter and such tomorrow.

    Could the muffler have anything to do with this? Oil is leaking from the head where it connects to the muffler, and there is no gasket there. Was no gasket going from the card to head either, till I found a tiny bit of material to make one. Guy I bought this from had no clue.. complete idiot. Ahh well, I'm learning now so when I do my own build I'll have all the knowledge to do it right the first time!
     
  8. tooljunkie

    tooljunkie Member

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    patience is a virtue,chuck.
    my favorite job was at a hardware/auto parts store.9 years selling parts.
    i have used high temp silicone for exhaust sealing on snowmobiles for years,trick is to let it dry for 10-15 minutes before you re-install pipe.a good smear (about as thick as a gasket) and let it sit.
    http://www.motorizedbicycle.ca/pages/SkyHawk.pdf

    something to browse
     
    #8 tooljunkie, May 12, 2012
    Last edited: May 12, 2012
  9. boardman

    boardman New Member

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    .crt.wow i will say that again
    chuckl333 i just took the 80cc moter out of my mountain bike and put it on my new beach cruiser it took me 2 days to complete as i was also working on a moter coach fuel pump ANYWAY it ran great before i put it on the cruiser but now runs crappy OMG LOL
    i got 2 gallons of gas from the moter coach OOOPS WONT DO THAT AGAIN
    THAT GAS ACTUALLY SMELLED BAD BUT I USED IT ANYWAY JUST BEFORE I TOOK IT OFF THE MT BIKE
    i didnt even run it after filling it up and forgot about getting that gas
    i think that the gas i got had like stp gas treatment in it
    so now im draining my tank GETTING FRESH GAS
    IM GLAD I DID NOT RUN IT THAT MUCH I THINK IT MAY LIVE LOL
    LOOKING AT YOURE POST REMINDED ME OF THE FREE GAS I GOT AND WHERE IT CAME FROM SO IL POST AGAIN IF THAT FIXES THE BOGGING OUT AT FULL THROTTLE PROBLEM
    PS
    YES ITS BROKE IN AND I DONT WANT IT TO BREAK ITS MY TRANSPORTATION LOL
     
  10. kody tyler

    kody tyler New Member

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    Hi my name kody and I seem to be chewing thru gas like it's going out of style and also I don't know how to tune my carburetor
     
  11. javy mcdees

    javy mcdees Active Member

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    when my engine used to chew thru gas I knew my cylinder was scored and needed a new one. How does it run? like crap or ok?
     
  12. kody tyler

    kody tyler New Member

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  13. kody tyler

    kody tyler New Member

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    Plus I just got it as a birthday present
     
  14. javy mcdees

    javy mcdees Active Member

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    My birthday was crap, the new cylinder I had ported had honed to size lasted 4 miles and the sleeve fell down. then the other good steel sleeve cylinder I had replaced suffered a broken exhaust stud on my way to work, so that cylinder needs repair. With all the rain lately my week has been real bad for me. Also on the way back from work one day the keyway for the crank gear spit out and had to get a ride home. Now I have a GT5 cylinder that is plated bore so that will only last so long but for now it runs pretty good. still goes 40 mph and has a bit more low end power. Oh and got hit last night by a lady in a lexus with an ******* BF i ended up video taping. But I was lucky I scratched her mirror as she went by me, when she parked at the gas station I confronted her and she was in some form of having a bad night and had no clue she even hit me. I let it go but got some video of the loser BF yelling at me. What a shitty summer so far. and it is pouring right now. 20190615_110439.jpg
     
  15. allen standley

    allen standley Well-Known Member

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    Hang in there Javey, Things will turn for ya. So what's up with the mower deck pic?
     
    javy mcdees likes this.
  16. javy mcdees

    javy mcdees Active Member

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    when it rains it pours! the missing pulley had the bearing lock up and the way the Gravely mower designed the deck the locked up bearing spun the lock nut right off and chucked the pulley off without destroying the $80 blades belt. so a bit of bad luck and a bit of good luck.
     
  17. kody tyler

    kody tyler New Member

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    Ever since I swapped my motor over to my new frame it doesn't want to start although it sounds like it wants to so I don't know what to do if anyone is there that's had this problem could you please reply to my trend telling me what you did to fix the problem
     
  18. kody tyler

    kody tyler New Member

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    IMG_0609.JPG

    This is the frame that it was originally on
     
  19. Harold N. Cisneros

    Harold N. Cisneros New Member

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    What I found when my engine bogged down when I gave it throttle was the fiel filter! I replaced it and voila it ran full bore again!
     
  20. allen standley

    allen standley Well-Known Member

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    Check wiring to be sure it has good connections. Also, if the engine is mounted, tipped too far forward it will cause the float in the bowl to allow too much fuel in. Flooding the engine with fuel. The carb should be as level as you can possibly get it. A little forgiveness is built in but the carb should be level.
    Let's see a pic of the motor in the new frame.
     
    #20 allen standley, Jul 17, 2019
    Last edited: Jul 17, 2019

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