First ride of the year

Discussion in 'Motorized Bicycle General Discussion' started by proneto911, Mar 7, 2015.

  1. proneto911

    proneto911 New Member

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    Well since it was about 50 in Chicago today decided to take the motorbicycle out for a spin. Took the head off and I know there was marks but couldn't feel anything with my nail so it was good. Put a new B6HS in and have it gauged at about .024 or.025 need to put it down a little to get it to .023 seems like a safe medium. First startup was interesting didn't want to turn kept sliding but I also had the he's off and pushed it down all the way to bottom center. Felt that and everything being sticky over the winter didn't help any lol but got it running.

    I do get knocking sound when I'm twisting the throttle but goes away when I he off it I don't think it anything but thought id get opinions. I am running 50:1 right now. I am going to look at the plug and see if anything is off with the color. But other than that everything is operating really well.
     
  2. mapbike

    mapbike Active Member

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    hope you get it figured out a plugging along asap....

    If it aint raining here Monday I plan to take me a 12+ mile ride sometimes after noon, been itching to get one of my bikes out on the road again since its suppose to be mid to upper 50s here ne,t week.
     
  3. Davezilla

    Davezilla New Member

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    Same here.... been in the high 30's every morning and the roads wet and slick so the bike has been parked more than I want it to be, I don't mind the cold for a quick shot up the street but the bike definitely likes to he warmed up before it performs right so I usually need to let it sit and idle for about 10 minutes before I go and then try not to leave it shut off for kore than 10 minutes once I get to my favorite taco shop in the mornings so I get my food and take it back to the shop to eat it. These engines can cool down a lot in just 10 minutes when the temp outside is in the low 40's or less and its noticeable when the engines not all the way warmed up, I'll lose about 3mph or so once the engine cools down for more than just a few minutes, but it does make nice power when the outside temp is that low.
     
  4. Greg58

    Greg58 Well-Known Member

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    The knocking sound you hear could be a leaking head gasket, if the head is not flat try lapping it on sandpaper over a pane of glass.
     
  5. bluegoatwoods

    bluegoatwoods Active Member

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    I plan on starting up my new MB today.

    It's been ready for about a month. And could have been ready before that. But in the heart of winter I simply didn't want to bring it up out of the basement. Mostly because I expect to have to do some tinkering and didn't really want to do it when the temps were getting up to 15 degrees or so at best. Once it comes out of the basement, it's not going back down there.

    Now we're getting temperatures that'll allow me to give it those final adjustments and get it broken in.

    Finally!
     
  6. proneto911

    proneto911 New Member

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    I appreciate the info Greg58 I will definitely take the head off and take a lol at it. I might eliminate the metal gasket all together and see how it goes up and down the block less than 1/2 mile so don't think it will damage it. Although it is metal and the notched side is up so that might be another reason as well.
     
  7. mapbike

    mapbike Active Member

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    Dont remove head gasket unless you plan to surface the cylinder deck and the head, you would also need to do a good check for clearance between head and piston dome, some of the engines like the GT5 and what we call the Half Breed have plenty of piston to head clearance since piston in half breed engines sits about .062" down in the hole at TDC but if its a 40mm stroke PK80 type engine the piston will hit the head if you dont use a gasket unless you add an extra base gasket between cylinder jug and case.

    Just wanted to offer a little info here that may save you some trouble.

    are you running stock kit type head on your engine?

    the reason I ask is because the pedal chopper square heads require a shorter spark plug than the stock heads or any of the other heads like the Fred Head, Jake Head, etc.if the piston sits at the ideal height at TDC.

    so If you have a pedal chopper type head on it a Champion J8C is the perfect spark plug length and of course there are others like the Autolite 285 if I remember right and many more that will work.

    One more thing I want to add, is that if the "knocking" noise isnt a hammering sound and more of a ticking or kinda pinging sound, some of that noise is normal with these engines, but I would pull the head and investigate just to make sure everything you can see is the way it should be.

    best wishes
     
  8. Davezilla

    Davezilla New Member

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    Yup... definitely investigate... some ticking is normal but if the piston is hitting the spark plug or the head, that's not good. some setups will barely clear eachother when the engine is cold, but will make contact once warmed up, the engine will still run too so it's doing damage if it's hitting the head. Look at the piston crown and hopefully there's no tell tale silver ring on top of the piston or that nice clean spot right in the middle...
    Better safe than sorry.
     
  9. proneto911

    proneto911 New Member

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    Well its not hitting anything I can see no marks. I did however find that the arm reads FM80 so its a GT5 I think from what another poster in another post I made said about the arms. But I think I'm going to keep it safe and keep the metal head gasket on. I way want to replace it the ring looks like it bent up but not sure where to get a replacement yet. Its not life and death but something I might want to do in the future.
     
  10. mapbike

    mapbike Active Member

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    Yes the engines with the 114mm length connecting rod that says FM80 is a GT5 38mm stroke geometry engine.
     

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