tunning up bike not enough power?

Discussion in 'General Bike Discussion' started by murduk0420, Mar 16, 2010.

  1. murduk0420

    murduk0420 New Member

    7
    0
    0
    I have a 78' murray montery with an 80 cc engine from ebay that I just finished putting together but it's not producing enough power like it's holding back some how. I have the throttle pin set at the last ending closest to dish for a rich mix any hints or advice to not be so slow would be apreciated.
     
  2. retromike3

    retromike3 retromike3

    274
    0
    16
    too rich ?

    If your putting to much gas in you might be flooding it.

    after you set it back to stock I would check the seal around the carb for leaks and then make sure the head bolts are on tight enough (12 pounds per inch)

    Next check the gap in the spark plug (I think it was 024) Also check to see if you have a good spark(take out the spark plug put the wire back on, lay it on the head let out the clutch and give the pedal a spin, if you have spark then your OK there.

    Finally what is your mixture? check the specks and see if you have too much oil in your gas.
    Mike Frye the bike guy
     

  3. retromike3

    retromike3 retromike3

    274
    0
    16
    one more thing

    is your carb being choked? usually up choke and down is off.

    If your engine is choked you wont get enough power.

    Mike the bike guy
     
  4. craisin

    craisin New Member

    527
    0
    0
    Well with these 2 strokes the whole crankcase should be considered as part of the induction system. And often if the bike is dropped and the crankcase hits the road it can cause induction system leaks.
    I am not saying that is the problem just it can be a problem with 2 strokes.

    As Mike suggests you may be running it too rich

    Go for a ride on the bike and turn the gas off while you are running it down the road if the engine picks up and runs better before it runs the carb dry indicates it running rich:thumbsup:
     
  5. retromike3

    retromike3 retromike3

    274
    0
    16
    check the spark plug

    Next thing to do would be to check the spark plug. If or when you take it off look at the front of the plug. it should be light tan color, if its black and suety its got to much gas. check the board I am sure that there are pictures of good and bad plugs.

    Mike Frye the bike guy
     
  6. murduk0420

    murduk0420 New Member

    7
    0
    0
    ok, let's say I'm running a 25 to 1 gas to oil ratio and I have the throttle clip set on the end of the pin for a rich mix would that deminish the performance or lack of power issue. :)
     
  7. craisin

    craisin New Member

    527
    0
    0
    have a look at the plug like mike says or go for a ride and turn off the gas
     
  8. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

    12,349
    650
    113
    I noticed my Harley cutting out today around 80MPH, but that was just the rev-limiter kicking in in 4th gear...
     
  9. craisin

    craisin New Member

    527
    0
    0
    hey Hack should go faster than that surely
    the rear cylinder has a tendency to run hot on those and the studs that hold the head and barrel to the crankcase are inclined to stretch on the exhaust side of the rear cylinder and can blow the gasket
    Im not a Harley fan but friends get addvice off me and Ive encountered 2 with blown rear head gaskets:thumbsup:
     
  10. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

    12,349
    650
    113
    Craisin, the solution was to shift into 5th. I've downshifted to pass traffic and hit the rev-limiter a few times. It goes like this "WAAHHHHHHHHHHHHHHHHHHHHHH" to [silence].
     
  11. craisin

    craisin New Member

    527
    0
    0
    get one of these Hack may be a lot older but faster
     

    Attached Files:

  12. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

    12,349
    650
    113
    I'll keep my electric start and fuel injection for cold mornings, thank you.
     
  13. retromike3

    retromike3 retromike3

    274
    0
    16
    true but

    what bike do you think Lawrence of Arabia would have driven? I know were getting off topic but.:p
     
  14. retromike3

    retromike3 retromike3

    274
    0
    16
    and Hacks bike is still faster but not "cooler"(subjective alert)
     
  15. craisin

    craisin New Member

    527
    0
    0
    a stock Vincent set a record 148mph in the early 50s and the guy lay on the seat with his boots hanging over the back of the seat
    Lawrence had a Brough Superior

    Yeah Hack that Vincent count put you over the handle bars
     
  16. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

    12,349
    650
    113
    If I wanted to go fast, I would have kept the Goldwing, or traded it for a VTX1800. But I'll live much longer with the Harely.
     
  17. camlifter

    camlifter New Member

    7
    0
    0
    you'll need to put the needle clip back to the middle, these carbs run rich as it is. the 25-1 is ok for break in but after the first tank of gas i go to 32-1. the over long break in period recommended by the sellers is over kill, they break in prety fast. most of the kits the carb dosen't seat well onto the manifold, the slots on the carb for the clamp to squeeze it to the manifold are sometimes still exposed when the carb is all the way pushed onto the manifold, you may need to use an O ring or silicon to seal it. once you have it running ok it's still going to be rich, you can buy jets on line or solder the jet closed and redrill it smaller. jetting the carb is the trick to getting good power out of these. also after a few miles it will quiet down some and run better. if it seems to stutter and miss at wot it's still running way to rich. hope this helps.