Prep Work for Building 2 Stroke?

Discussion in '2-Stroke Engines' started by angus, Feb 4, 2008.

Tags: Add Tags
  1. angus

    angus Guest

    Hi everyone! This is my first thread therefore please let me know if I've missed the target with regard to location / topic.

    I just received the 48cc 2 stroke from ThatsDax. <BTW the service was good.> I've reburbished an old Murray cruiser (ca 1985) and am getting ready to install the frame-mounted motor on it.

    I was wondering whether there is prep work that you all would recommend to make the build easier / more reliable? (e.g. change-out fasteners?) Are there steps that I can take ahead of the actual build?

    I didn't see this information via a search; however, point me in that direction if it does exist. Thanks.

  2. fetor56

    fetor56 Guest

    Your in the right section and yours is an excellent question.I've never seen any threads myself about this subject but that doesn't mean they don't exist.If they don't exist it's your idea so u start one,if ya like.
    Anyway with prepping i just make sure my bike is ALL in good condition(bearings,spokes,wheels,gears,etc) and that the tyres are new(bought for my riding style) and are as bulletproof as i can get them.Obviously the engine fits the frame and other than that if it's second-hand bring it back as far as possible to new condition...IMPROVED. :)
  3. Bean Oil

    Bean Oil Guest

    Here's a thread that you might find useful: Things you wish you done the first time.

    In addition, may I suggest that one take the time to read through as many pages of this particular forum's index; the Frame-Mounted Engines & Drive-Trains forum that is... as well as any others that you may have the patience for. You'll find many additional threads titled in subjects that may pertain to your build.

    It is perfectly understandable that you might be chomping at the bit to get this thing built, but take it easy. Your patience will be rewarded in the long run.
  4. hot70cc

    hot70cc Guest

    Bean Oil answered that question Fetor, all the information you would look for before installation and engine prep. I'm sure there is some inform. , that you may want to know that is not there, but most is , good luck
  5. fetor56

    fetor56 Guest

    I don't care if billions of Arnold Schwarzenegger clones answered the question,just as long as Angus goes away with a GOOD understanding of what's involved.
  6. gone_fishin

    gone_fishin Guest

    prezactly on all points...

    angus: smart, as you learn and have more questions or comments, just post a "reply" to this'll be your journal, & we'll all watch and help as needed.

    meantime, as fetor's become good about pointing out, keep reading :)

    have a good look at the "BICYCLE" forum, too. remember, you're about to subject yours to a sustained 30mph & it's not necessarily gonna play nice about it.

    and i agree with 70cc, bean's link is a helpful it, bring your questions back to this thread...better still, make use of proper terms as you learn 'em to get even better at searching.

    if you'd like to rename the thread to reflect it's your "project-topic" lemme know. keep in mind...the next new builder will be reading this one ;)

    now the fun begins :cool:
  7. hot70cc

    hot70cc Guest

    ?????? What the #$% i wasn't trying to be and azz. i was clearly stating that Bean had caught what Angus was looking for. What does arnold have to do with it. Geesh a little testy dont ya think. lol
  8. angus

    angus Guest

    Thanks for the responses everyone. I'll keep you in the loop as I move forward and attempt to post some pics.

    Bean Oil - Thanks for that link. It was very helpful.
  9. fetor56

    fetor56 Guest

    Let's just put it down to a misunderstanding then and move on,okie dokie.
  10. hot70cc

    hot70cc Guest

    sound good to me, like i said i wasn't trying to come off to being an azz
  11. Skyliner70cc

    Skyliner70cc Active Member

    Here are some tips that I use:
    1. replace all bolts/nuts/etc... with quality US made stuff. I use threaded metric rod to replace all studs on the engine. I use metric couplers for engine mounts instead of nuts because their length allows more thread grip for greater torque tightening.

    2. Double sided tape: Put strip of double sided tape under fuel tank and press tank firmly on frame. Makes install of frame retaining bolts easier and requires less torque on tank bolts for tank to remain in place. Some fuel tanks fail (leak) if the studs are tightened down too much..causing the studs to elongate and partially pull out of the tank.

    3. Double sided tape on chain tensioner/bracket. Less frame scratching when repositioning.

    4. Double sided tape on back side of CDI. Easier install if bracket is too small for frame and can get away with zip tie to hold CDI in place.

    5. Cut to remove factory electrical connectors. The circullar connectors spread too easily and over time will come undone. Easy fix is to use quality sealed connectors (jack/spade) from Radio Shack. Heat shrink/solder all fittings and you won't have to worry about vibration causing a crimped wire to become dislodged.

    6. Kill switch: that cheap red button kill switch will fail. Solution: aftermarket kill switch or throttle wiht one built into it.

    7. Pour small amount of oil into spark plug hole to lube engine before first start.

    8. LOCTITE everything regardless of what manufacturer says (Dax)

    9. Don't baby your engine during break in. Drive it as you normally would but don't beat on an engine that isn't warmed up fully.

    10. Castor oil baby! At least 20% in your fuel mixture will save that bushing conrod.

    11. Boring out your exhaust only makes it sound louder. The power versus noise gain is not worth it in my opinioin.

    12. Use lowest octane fuel possible unless you have tons of carbon build up on your cylinder head. These low compression engines (6.6:1 last time I read) can be run on kerosene in a pinch without much problem.

    13. Watch for chain stretch. Don't ride a bike with a loose chain and keep eye on chain for first 100 miles. It will stretch and require lots of incremental adjustments. Nothing worse than throwing a chain at full throttle. It can cause rear wheel to lock up; cause chain to hit your leg or crack your engine case; and scare the %^&*( out of you.

    14. Bluejeans, and NOT spandex, should be worn when riding a motorized bike. Save the spandex for the gym or the olympic cycling team. Helmets are ok.

    15. Motorized bikes are car magnets. Ride defensively.

    16. Play it safe and kill engine when encountering cops. At very least, faux pedal at low (quiet) throttle as you pass a police officer.

    17. Its ok to laugh when you pass cyclist pedalling up a steep hill. Its ok to expresss that your wrist hurts from twisting the throttle for long periods of time but don't expect any pity.
  12. angus

    angus Guest

    Skyliner: Awsome response! Thanks! I was hoping for the small tricks of the build to help avoid the pain down the road! :) I'll let you all know how it comes out.
  13. angus

    angus Guest

  14. srdavo

    srdavo Active Member

    I've always wrapped my frames with a section of innertube (under the gas tank). the tank grips well, without a lot of torque on the tank studs.

    But...I'm really liking the idea of the Double sided tape!!
  15. Skyliner70cc

    Skyliner70cc Active Member

    Additional tips:

    Plastic throttle assembly with kill switch: Its hard to tighten this assembly enough so it won't loosen and rotate. The plastic splits easily if you try to snug it down. Solution is to tighten and then drill a small hole and install a small black sheet metal screw. This prevents rotation and improves safety and prevents breaking the throttle assembly during install.

    Carb tips: I have had my main jet in carb loosen and fall into the float bowl. Every carb gets disassembled and jets and bolts are loctited.

    Engine clutch cover: Had had bolts loosen on clutch side of engine. Bolts loctited into place.

    Clutch cable: I don't like idea of a small retaining bolt to hold clutch cable setting. Once property setting is obtained, I solder the cable onto the little brass cable clip that pulls against the clutch lever assembly. Rationale: peace of mind. Removal is easy, a quick burst of heat from torch allows bolt to be loosened.

    Speedometer: digital speedo from walmart that was recently clearanced for 5 bucks works perfectly with no interference issues.

    Muffler pedal clearance: Instead of using heat to bend the exhaust which often damages the finish, I can get enough pedal clearance by removing the pedal and grinding it down a bit. Works 99% of the time.
  16. angus

    angus Guest

    Cool! Thanks Skyliner! :)
  17. angus

    angus Guest

    I've noticed that the throttle does not appear to fit over the handlebar. The end clamp does (i.e. the metal collar with tightening fasterners); however, the actual handle beyond the collar does not fit the handlebar. Any thoughts?
  18. fetor56

    fetor56 Guest

    Angle-grind then smooth the doesn't matter if their steel or aluminium(aluminium is much easier) it still works.
  19. angus

    angus Guest

    Thanks for the input here. I ended up taking the throttle assembly apart and warmed-up the white plastic piece to soften it. I was able to grease the handlebar (up to where the throttle assembly clamp bites into the handlebar) and easily slide it on. I don't mind grinding / shaping but I try to avoid it if possible!
  20. angus

    angus Guest

    I really didn't want to put any force on the studs' attachment to the tank. Therefore, I bought additional nuts and screwed them not quite all the way to the tank (loctite) and made a second bracket that fits over the top bar and butts up against the new nuts. I put the original brackets on underneath the top tube forming a clamp that puts the force on the stud (only) and not on the stud / tank joint (with the exception of any sideways force generated by tightening the brackets).

    The tank sits a wee bit higher due to the new top bracket, but I hope that the force on the stud / tank joint is negligble. This allows me to really tighten the tank down without fear of rupturing it (at least I hope so! ;)).