Slower After Gasket Replacement?

Discussion in 'Motorized Bicycle General Discussion' started by >ScCruisin<, Jun 15, 2009.

  1. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    I recently viewed the Tip sticky and decided to go out and buy some high temp gasket paper and fix a couple other things with my bike,thread lock etc...
    So I made some gaskets for the carburetor and the muffler. The old one on the carb was practically all gone, melted almost, and the muffler one was cracked, burnt, and oily. I replaced the 2 and tightened everything back up, using thread lock to secure it all. I started up my bike to let it warm up and the first thing i noticed was that it was quieter and seemed like it was idling at a lower rpm than usual. It almost sounded weaker for some reason, too. I walked back in my garage to let it warm up, and i heard it stall. This has never happened before. So i started her back up, then adjusted the idle screw to what i remembered the engine sounded like previous to me fixing the gaskets.
    When I took it for a ride, it just felt like it had a little less power and speed for some reason. The bike kept bogging down at WOT at first, but got better as I rode.
    I noticed it performing not as well as it did before in general...any ideas guys? Thanks a bunch!:-||
     
  2. reg454

    reg454 New Member

    Joined:
    Jan 11, 2009
    Messages:
    269
    Likes Received:
    0
    When you remade the gaskets did you make sure they were the same size as the intake flange and exhaust flange. ie the holes were as big. if the intake one was smaller then you would be getting less fuel and air to your motor and if your exhaust wasn't you would get less flow through your pipe and it would decrease the hp.

    Can you post some pics of the before and after for us.
     
  3. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,169
    Likes Received:
    17
    It feels like it has less power because there is more pressure in the exaust now! (no leaks)
    And the idle is lower because there isn't anymore air leaking into the intake manifold...
    It sounds like you did everything right!!! "Good job"... Now just readjust the idle screw.
     
  4. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    Reg, I just put it all back together so i dont really want to rip it apart again, but i will if i have to. And I made sure that all the holes were pretty much identical, it definetly wasnt enough to reduce power. And venice, so what im feeling is good?!? will it ever go back to how it was, or do i now just have an engine with a little less power but its sealed off better so it will be better for it in the long run? Thanks...
     
  5. reg454

    reg454 New Member

    Joined:
    Jan 11, 2009
    Messages:
    269
    Likes Received:
    0
    ok ScCruisin. you might want to try a different exhaust then from what Venice Boy said. Or you could take the end off of your exhaust ant cut an inch off the pipe that is in it mounted to the end cap.
     
  6. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    If you sealed it all up, you may be running a bit rich. Check your plug and adjust the "C" clip if needed.

    Also, if the exhaust was really leaking badly, you will have a little less power, and noise.
     
  7. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    Sorry Im new to most of this...what is the C clip and how to i adjust it? And my plug should be brown right? not black or white? Thanks in advance.
     
  8. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,301
    Likes Received:
    25
    Do not screw around with the exhaust. Don't take the end cap off and don't shorten anything. The 'C' clip is inside the carb. It is on the needle that the throttle cable pulls. It is a small 'C' shaped clip that depending on which groove on the brass needle it is in determines your mixture. Upper grooves give you less fuel,a leaner mix, the lower grooves richen the mixture. Do what BikeGuy Joe suggested. You were probably running lean due to air leaks in your intake and exhaust. A dark plug indicates a rich mixture. A light brown or white plug tells you that you're running lean. Ideally you want the porcelain of the plug a tan to brown color. Keep us posted on what you find and we're here to help. At least most of us are.
    Tom
     
    #8 2door, Jun 16, 2009
    Last edited: Jun 16, 2009
  9. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    Thanks Tom...
    I notice the engine to be running more smooth and consistent, if you know what i mean(im sure you do). But i just dont have the acceleration or top end that i did before the gasket replacement. Its not a huge difference, but definitely noticeable. I will look at the plug in the morning when i get the chance to see and report how my engine is running. Im not sure if this means anything, but im almost positive that i notice more smoke coming out of the exhaust since the gasket change also. Could this have something to do with my change in power, or maybe a clue as to whats wrong with my bike, which im pretty confident is a very minor issue,,,
    Thanks,
    Chris
    l
     
  10. Junster

    Junster New Member

    Joined:
    Jun 2, 2009
    Messages:
    445
    Likes Received:
    0
    I agree you sealed up your leaks that were causing the motor to run leaner. Now that's it's sealed up you need to lean out the carb a little.
     
  11. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,301
    Likes Received:
    25
    SC,
    A leaner running engine will always have a little more power than a rich burn but you can go too far so if you want to try the 'C' clip position change go one groove up at a time. What Bike Guy Joe and Venice Boy is telling you is correct. You sealed things up like they're supposed to be so now you're probably a little on the rich side. Not a really bad thing but your engine will perform better with just a little less fuel to air mixture. You haven't said how old this engine is or if it's broken in yet or not. The Chinese 2 strokes will gain power as they are run more. You fuel to oil ratio is also an important issue. What is the ratio you're running and is your fuel mix a recent one. Mixed 2 stoke gas/oil seems to have a limited shelf life and the fresher the mix the better your engine will run. Hope these suggestions help you.
    Tom
     
  12. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    Thanks for all the help guys. I'm sure that's what the problem is. Its a relatively new engine, with maybe just short of 200 miles on it. The guy i bought it from swore by the 32:1 ratio, but from what Ive read this might be a bit rich. Especially after i sealed everything up better, right?? So I guess I will lean it out a bit. And 1 more time, just so I'm clear, i need to take my carb off and adjust a 'c' shaped clip inside it, and just one notch to start with, ya? And which direction again? I know that this has all been asked again and again, I am just horrible at using the search function, and not quite confident enough with these engines to assume what I'm doing is correct...So if someone could either tell me a quick step by step on how to lean out my carb, or just direct to a link where it will tell me how, i know its out there.
    Thanks again for all the help guys, i don't know what I would do without this wonderful forum...
    Chris.
     
  13. >ScCruisin<

    >ScCruisin< New Member

    Joined:
    May 29, 2009
    Messages:
    23
    Likes Received:
    0
    [​IMG]

    Sorry for the double post, but heres a picture of my spark plug if it helps anyone. As you can see, its black and oily around the threads, then the part which actually sparks, pardon me for lack of proper terms, is a really dark brown, almost black. This part looks dry, while the rest seems oily....
     
  14. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    That's not too bad. You can move the C clip up one notch and ride it for awhile. If it seems worse, go back down to where you started.
     
  15. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    I will say that you may have lost a little power when you sealed everything up....it's better to have a little less power and a good reliable engine than to have an engine that burns up like a ten dollar pistol.
     

Share This Page