what did you do to your motorized bicycle today?

Discussion in 'Motorized Bicycle General Discussion' started by Skarrd, Oct 25, 2010.

  1. trialnerror

    trialnerror New Member

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    That sounds about right, In my opinion, if the key was good.
    just a quick question on fuel delivery, does that engine have a reed valve as part of the intake system? maybe the reed is stuck- will it fire if you spray a shot of good fuel into the spark plug hole and put the plug back in?
     
  2. Davezilla

    Davezilla New Member

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    Yup... the key is good and I attempted the start with fresh fuel and freshly rebuilt the carb... so pretty much the only thing left is bad timing unless the magnet is so weak that it can make a spark outside the cylinder but not under compression, but I doubt that's the problem since it's spark is nice, bright, and strong. Didn't have time to lookat it today but I'm leaning more and more toward it being off timing. This engine is still piston port and not modified in any way but it's possible the guy got a lemon from the start or got that mag rotor off another engine where the keyways might be clocked different enough for the timing to be too far off to fire the cylinder, I know the fresh fuel is making it into the cylinder too since it is coming out the exhaust pipe after motoring the engine for about 30 seconds with a cordless drill.
    Since I got another engine on order I'll most likely just install that one on his bike and keep his old one since there's like zero wear in his cylinder and on the rings, then I can take a better look at it once I got more time and find out exactly why it's not starting. I may put on one of my spare mag rotors to compare the clocking and see if he just got a bad rotor or the key slot on that crank is in the wrong place.
     
  3. Davezilla

    Davezilla New Member

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    Got a chance to do a test run with the 40 tooth rear sprocket installed and top speed felt faster but once I got to the resturaunt I noticed my gps was turned off on my phone, then on the run back the engine cooled down too much and I really didn't have enough time to let it properly warm up but was still able to record a 40mph top speed reached 4 stroking all the way...

    Also my 21mm carb finally got here and it's a perfect fit to the intakes MZMiami sells on ebay except it needs a small section of hose to couple the 2 together since the Dellorto clone is a spigot mount type. It'll probably be next weekend before I'll have the time to install and tune it since I set up a job this sunday to change out a rear main seal on a customer's car and won't have the time to mess with the bike this weekend.
     
    #7843 Davezilla, Mar 10, 2015
    Last edited: Mar 10, 2015
  4. mapbike

    mapbike Active Member

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    excellent.......
     
  5. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    I parked it and pedaled my mtn. bike in the dirt today :D

    A great day off today!

    .wee.
     
  6. Eric2.0

    Eric2.0 New Member

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    I go the flu and haven't touched my bike.

    Nature is friggin hilarious.
     
  7. Davezilla

    Davezilla New Member

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    Just getting over the flu from last week... I feel a LOT better now but still coughing up all kinds of neon green stuff...

    Did another speed test run again this morning but again not enough of a warmup, but was able to get it up to 41mph while 4 stroking like crazy... Maybe when I get to the shop in the morning i'll let the bike warm all the way up before leaving the shop and see if I can get a few more mph out of it... Acceleration with the 40 tooth rear is also very close to the same as it was with the 44 and it seems just a bit better on the pipe.
     
  8. Intrepid Wheelwoman

    Intrepid Wheelwoman New Member

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    Hercules maintenance day today :) I spent the afternoon working on both my Hercules trike and my Hercules bicycle. Both are essentially the same in most respects only my bicycle is English and entered this world 63 years ago and is in completely original condition with a respectable patina of age.
    My trike is based on a 12 year old Indian made ladies Hercules bicycle which is still a current model being made by Tungsten Industries who are the (cough, cough) present owners of the Hercules trade mark.

    It has taken some work to get the younger Hercules into reliable condition because the fasteners the Indian factory uses are complete rubbish and most of the fittings were stamped out of not especially good quality tinplate. As for the plating on the wheel rims, handlebars & etc, spit on them and you can watch the rust form before your startled gaze. Folk might slang off the Chinese and their bikes, but my heavyweight Wu Yang ladies bicycle is streets ahead of my Indian made Hercules in terms of quality.
    However the use of proper British fasteners and fittings have brought the younger Hercules to heel and up until now it has been very reliable. Unfortunately it is now back in the dog house as I have discovered during the maintenance session today that a ball bearing or two in the bottom bracket have started to break up. I am not surprised given the poor state of Indian metallurgy :(

    On the other hand all went very well with my English made Hercules. Oil cups make lubrication an easy task and all the ball bearing races are as smooth as silk. Something I've done over the years is scour second hand shops and junk shops for genuine old bicycle tools and I take great pleasure in using these tools to maintain my elderly bicycles.
    I don't like modern bicycles with their grease packed bearings; - though as we all well know most new bicycles sold in these decadent times are sold completely innocent of any grease on their bearing surfaces at all. When I take apart the bottom bracket bearings on my younger Hercules I will be drilling the bottom bracket casting for an oil cup and hopefully this will forestall any more unruly behaviour in that department.
    I am in the process of building a motorised attachment for my Hercules trike so I really do want to make sure that there will be no further problems with poor quality components as I have a good deal of work for my trike to do once it's new modifications are complete.
     
  9. mapbike

    mapbike Active Member

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    Had a chance to start working on an engine Im building from a bare case into the pmouse motor for the Yellow Schwinn build I started last year.

    Before I started on the engine I took a 10 mile ride to the post office to mail a package off, took the Green bike, was a good ride.

    also did some port work on a jug and swapped multiple jugs out on a lower with a 40mm stroke crank to see how the different jugs I have time with all the ports at BDC and TDC, so many different configurations, its no wonder there are some many of these engine that run so differently, I have 5 different type jugs in the shop right now and port timing is different on every one of them on the same engine.

    Having a good time with all of it though and thats all that matters right.....
     
  10. DRBS

    DRBS New Member

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    I also gave noticed the difference in the cylinders theres even a difference in the cranks ive noticed too. I bought a "high performance" crank and the diameter of the bearing shafts are different only buy a very small fraction buy there is a difference that must be why some shake more than others plus the difference in the ports would explain a lot LOL. ive been building these for going on 4 years and ive seen a lot of really messed up ones and a few that were fast right out of the box I should have kept one of the faster ones for myself LOL
     
  11. mapbike

    mapbike Active Member

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    The two main differen es Im seeing between the several type jugs I have is that first of all the jugs we're getting can be designed for three different engine geometries, even at that they're still very similar as far as height between base and deck with the one for the GT5 geometry being the shortest.

    main big different is in height of transfers and intake port measuring from the base, the cylinder bore extends between 10mm & 11mm below the base on all the jugs Ive measured which doesn't make any difference, but I measure it and then subtract that amount from the distance between cylinder and bottom of transfer or intake and I have found as much as 5mm difference between jugs and that is huge in determining how the engine is gonna act as far as low down grunt or higher rpm capability.

    Im thinking based on what Im seeing here that although port size is important, that isnt gonna matter much if the port timing is way off for what you're trying to achieve with the engine, A smaller port engine with correct port position for where you want the engine to run its best at is probably going to perform much better than an engine with huge ports that has then set way low or to high for the desire characteristics of the engine.

    Im no expert on any of this but after close to 6 years of messing with these engines Im starting to dig into them a little deeper to see what parts I need to be looking for to get what I want out of them.
    One thing Im definitely seeing is that the 40mm stroke geometry is by far the best, the pjugs just dont set well with these 38mm stroke engines, yeah they'll run ok, but for the average builder they will not run nearly as good as the 40mm stroke engine when its set up right, the PK80 engines have for less port timing issues just as Fred has stated in his videos and Im finding it to be completely accurate.

    Ifeally hope Duane @ thatsdax will go back to the 40mm stroke GenIV engines, the cranks are better and for higher performance builds they are the winners above the GT5 geometry for me.
     
  12. TakeiT

    TakeiT New Member

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    Oh where do I start...My exhaust wouldn't stop leaking, no matter what I did. I pulled it off and wire wheeled it and found that the flange wasn't completely flat (Casting problem). So I ground that down, polished the whole pipe up, and put gasket sealer on it. There was oil dripping down the cylinder into the mag compartment, and when I removed the lowest bolt oil poured out. Pulled it apart, brake cleaner and compressed air cleaned it out. While I was at it, I cut the white wire off and the blue one, soldered a new one on that was long enough to go up to where I wanted my CDI. Also put a new clutch cable on and greased the wheel bearings, gave it a once over. I've been running 32:1 but will probably start going 40:1. Rebuilt the carb, changed the spark plug wire (Probably didn't have to, but for the $5 it cost for the wire and boot, might as well). Also trued up the rear wheel which I bent a spoke on last year and never fixed

    Worked on it from 10am till 7pm. Going to probably make a wood "Tank" for the cruiser frame and stain it a dark color to hide the electronics in (Of course, make them accessible if need be), wire up the lights and horn.
     
  13. DRBS

    DRBS New Member

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    I just bought a step up transformer going to hook it to the white wire and run all my 12v lights off it and hook up a cigarette lighter socket to it so I can charge my phone ect on the bike also thinking about getting a small emergency light battery and hooking it up to run a car stereo don't know if it will charge the battery from the step up but worth trying ill let you all know how it works and if it works good ill be selling a box that you can hook up to the white wire and run 12v items on your bikes should get my hub adapter on Monday so I will find out how everything goes post pics on Tuesday
     
  14. mapbike

    mapbike Active Member

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    Cool, I'll be watching your results.
     
  15. TakeiT

    TakeiT New Member

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    just found out that the leak i mentioned above isn't the exhaust (Though that was leaking too) The head is leaking oil, the crank seal is bad and I haven't pulled it apart yet, was just out for a ride when I had less power than normal, going to pull it apart when it cools off
     
  16. Davezilla

    Davezilla New Member

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    Got some free time at the shop today so I finished installing a new engine in a customer's bike but now I need to order a chain since his 415 chain rubs inside the front Sprocket housing, I may just go in and trim things to fit depending on how much free time I get this week but that's where I'm at with his bike now.

    For mine I did the re jet on the stock carb and I'll test it out In the morning if the weather permits... got my 21mm carb in last week but I need to make an intake that angles it off to the side enough to clear the seat post before I can use it. I also scored last week on 2 kx65 pipes so I'm also in the process of making a thick flange and header to use one of these pipes.
     
  17. DRBS

    DRBS New Member

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    xct2just a suggestion. when you put the head back on get 4 nuts that fit the cylinder bolts and tighten them down first then put the acorn nuts on. I have found that sometimes the nuts bottom out and you think that the head is torqued down to 12 foot pounds when really there not. I used allthread connectors as my bolts they work great and I put a small stud in and tighten the acorns to them they look like a taller acorn nut and your sure to get the right torque.
     
  18. Davezilla

    Davezilla New Member

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    I've already done all that as well as a quick port cleanup, widened both intake and exhaust ports by 2mm, then I ramped the piston at the exhaust and transfers down 1mm and in 10mm to aim the transfer flow toad the intake side and help prevent short circuiting. This port job is by far not a hot setup for winning races but for typical street use on a 60lb bike and a 275lb rider I wanted to be sure this engine makes really good torque and still has the ability to Rev to around 7500 rim for a top speed over 30 but not past 35 or so... we definitely want more torque for this setup.
    For the acorn nuts I kept them but used 2 washers and checked that there was more than enough clearance before torque the head down... I'll most likely put a Fred head and an expansion chamber on this one before he takes his bike back so this engine will be nice once those 2 upgrades are done. I just gotta remember how much this bike and it's rider weigh to keep it from being too sluggish at low speed. The option is also open for a reed valve which would give even more torque and I'll do the piston mods so it don't lose rim if I do reed valve it.
     
  19. DRBS

    DRBS New Member

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    xct2you especially want the al thread connectors when you go to the fred head the regular nuts seem to "get lost" in the head since there is taller fins LOL just a suggestion
     
  20. bluegoatwoods

    bluegoatwoods New Member

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    I started the day by changing my pedal chain. The old one had given me some trouble on Friday.

    Then I swapped out my studded winter tires for some regular tires. Then I spent some time getting aggravated at the task of making sure that the various alignments were okay. It's a new bike so I'm still getting used to finding all of the sweet spots.

    Then I tracked down a bit of fuel drip that I'd been noticing. I had thought that that came from the float bowl drain screw. But it turned out to be from the nipple at the top that accepts the fuel line. I didn't manage to fix it since I don't have the right clamp. But I know where to get them. So I'll do that tomorrow.

    Then I moved the gas tank back to the top of the rear wheel. I kinda crave a bike that looks more like an old moped than a motorcycle. So this'll help in that respect. Plus the top tube location just wasn't convenient. The tank got in the way too much.

    DSCN0432.JPG

    Then, after a few shakedown cruises, I rode it uptown to get tacos and burritos for my daughter and myself.

    Not a bad day, all in all.
     

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