Umm. My bike I built.

Discussion in 'Introduce Yourself' started by Ardyce, Nov 25, 2010.

  1. Ardyce

    Ardyce New Member

    I built a bike. It is big. Lots of torque. I used an old lawn mower engine. 6 1/2 horse 190 cc briggs. It took a few months but I built the frame and its ugly as ****, but very strong. It is hard to keep the chain on. any ideas on a better tensioner I can make? I can machine it out and mill the pattern too. I like to fix up old tools and use them to build thing. My latest project is a 1984 King midas milling machine.

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  2. PatrickW

    PatrickW Staff Member

    Hi there, and welcome to MBc. Try a PM to SimpleSimon. He is a wizard at this sort of thing, and I am sure he would be glad to help. He is here on the Forums. Try him during the day.
  3. Ardyce

    Ardyce New Member

    Thank you sir. I cant wait to fix this issue.

    What do you think not bad for a first project? I got the raw materials from a junk yard.
  4. professor

    professor Active Member

    Hi Ardyce, I don't see the chain from the engine. Better pics would help.
    I found the alignment needs to be really good for chains to stay on.
    I do use an idler on the lower chain run.
  5. Ardyce

    Ardyce New Member

    Pictures Of the Project

    Her are all of the pictures on my phone that I took maybe this can spur some topical input.

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  6. Dave C

    Dave C Member

    If nothing else works i'd try splitting the distance with a half shaft attached to the seat post. Two little sprockets on a common keyed shaft to shorten the length of the chain. American Power Sports has sprockets for 5/8ths and 3/4 inch shafts.
  7. SimpleSimon

    SimpleSimon Active Member

    As others have said, the length of your chain run is a large part of the issue. That, and a seriously unbalanced weight distribution. You have an awful lot of engine on a very minimalist bike. I'm a little concerned with what you said about the engines origins, as well. Typically, vertical shaft engines don't do well when run horizontally - the lubrication systems usually are not designed to operate in that position.

    You asked me about your power side chain issues, and I can easily understand that you may be having such.

    First, the plane of rotation of the drive sprocket needs to be absolutely parallel with and co-planar with the plane of rotation of the driven wheel mounted sprocket. The best tool there is to establish that is a key chain laser, in my experience.

    Second, the length of chain is a big factor in the amount of stretch the chain will exhibit under load - the more links, the more stretch. Check chain tension constantly.

    Third, your idler on the return side is set to a sharp angle and closer to the sprocket than would be best. I'd suggest you take a straight edge and place it in contact with the underside of both sprockets, and then mark on your seat post the height a straight line chain run would cross it at. Remove the existing idler, and mount a spring loaded arm with idler cog (not a smooth idler wheel) to raise that bottom chain run at that point about one inch above straight.
  8. Ardyce

    Ardyce New Member

    Briggs vertical concoction.... still in the works

    I have come to a few conclusions based on your inputs. I machined out an aluminum idler ( It has a groove down the center to hold the chain and in the very center ,teeth that match the chain # 35 chain) "Simon". housed close to the cog to keep the chain fluid in its motion. I originally just wanted it to be smooth but the noise was bugging me so I notched the teeth to it. Nice.
    I like the idea on a jack-shaft so I took some stock 5/8 jack-shaft amongst my junk and am in the middle of making the sprockets for those. I do enjoy American outdoor. That is where I picked up the go kart clutch for it. Instead of mounting directly to the seat post ,I will make a bracket and house the 1/2 jack shaft directly behind the seat post( just lines up a bit better , more room.) I just need the integrity of the frame to stay the way it is because well lets face it, I have a vertical engine on it. She is quite stable. After it's first test ride yesterday I realized the placement of the gas take needed rearrangement so I poster it higher.
    The oil needs changed and it was gray at the moment so among careful inspection I realized the weather is very cold now so believe moisture is getting into the oil.....hmmm.... Maybe it has an aluminum head, not sure. Time to change the cap and the oil. I will do some more work and test's and let you know of some of my findings. I appreciate all of the input. Thanks guy's.
    Last edited: Nov 30, 2010
  9. kerf

    kerf Guest

    Could someone explain how a float style carb is working with the float bowl on it's side?

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  10. Ardyce

    Ardyce New Member

    She's running I took her down to work and picked up a pack of smokes for a celebratory 1st voyage. I am curious about the carb myself. The engine should flood but maybe there is a bypass and it just pooling in the hose but not yet I would like to turn her 90 degrees to avoid any future problems. Maybe I can machine a tight spacer to turn her into a horizontal right where the carb meets the engine. Any ideas?