First timers!

#1
Hello, my name is Danny. My son Owen and I are going to start working on his old (new style) Doodlebug DB30R. He has been riding since he was 3-1/2! He's 12 now and the old girl just ain't cool no more. It has been through a lot and really has been trouble free besides tires and bearings. We are just starting light, nothing crazy........yet. Ordered some parts from Eric and I am picking up a 212 from HF in about an hour. I am really looking forward to working on it with him and I am going to do my best not to do anything without him. It is gonna be hard not to, but I will refrain. He's a great kid! Can't wait to get started! image.jpeg
 
#4
Just got back from HF. I wanted the standard engine, but ended up getting the Hemi. I liked how the standard engine has extra threaded taps on the front of the gas tank mount. in case we need to make brackets to move tank to clear top rail. Oh well, we'll get it to work. Dying to open the box to have a peek. Gonna wait for my boy so he can do it. image.jpeg
 
#5
We were able to put some work in on it tonight. HE pulled engine. Then we slid the predator in. We ended up bending the rear lower fender support back about 1" to allow more room for the larger engine. Without the motor plate (it is coming tomorrow) it fits and should be no issues mounting and adjusting it. The gas cap is close. Right now, with no plate it is very doable on and off and should be no issue fueling it. We removed the wave washer from the linkage and it is very nice. Plenty of spring action for return. We will see once cable is connected. If not strong enough return, it is an easy fix with a quick trip to the local mom and pop hardware store for a spring. He also turned the pull start so the handle pulls straight up instead of forward. He disconnected oil switch and crimped a bullet connector on the bugs kill switch wire. we ended up ordering new tires for it that will be here Wednesday. We went with 6 ply knobby tires. Tomorrow, I am going to stop at a few places to see if I can find a new angled valve stem for the rear. Must admit, we are very excited about this little project.
 
#10
Used a conduit bender on 15 doodlebugs I have built .just put the bender so the hooks up top and the open part rests on the horizontal upper mount the neck bolt goes through. Gonna need 2 adults.one to sit on the bike and guide the bars and bike from falling and bars from twisting inward..
 
#11
Used a conduit bender on 15 doodlebugs I have built .just put the bender so the hooks up top and the open part rests on the horizontal upper mount the neck bolt goes through. Gonna need 2 adults.one to sit on the bike and guide the bars and bike from falling and bars from twisting inward..
Sounds about right!
 
#12
Some pics from yesterday. Nothing too exciting. I am gonna try to go back to HF and see if they will let me swap the gas tank from this one to the one on their display. It is the non epa tank and the fill is on the extreme corner. It would work perfect. I doubt they will. They all seem to hate working there.
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#14
So, looking at parts. All look good. I do have a question on the max torque clutch we got. It has about 2.5mm of play in and out on the engine shaft. Is it ok if I get some steel washers or shims to take up must of that? I would really like to see much less movement. I feel leaving it like that would not be a good choice. I see there are shims available, but they are made of aluminum. I would think steel would be better. If a pic is needed, let me know. Thanks.
 
#15
I think I found an answer on OldMiniBikes warehouse. Seems clutch should have movement in and out on the engine shaft. Mine is at .098". That Definetely falls in the .070-.100 range this says. Let me know if you think different.
A centrifugal clutch benefits from being able to "float" on the crankshaft slightly. If you have the clutch fixed to the crank and the sprocket fixed to the axle, there is no room for error in flex or mis-alignment

DO NOT ever use a 3/4" bore washer "on" the shaft or set screws to permanently position your clutch. (The only exception is a two piece clutch.) The standard clutch is no longer drilled and tapped for set screws because they are not needed. You never fix both sprockets in a locked position. Only the axle sprocket needs to be in a fixed position. A clutch must be able to float on the crankshaft so it can self align.
If the crankshaft or PTO of your engine is not long enough to pass through the clutch entirely, you can use a flat washer or two as a shim to add length to the crank. You would need one or two washers that are 5/16" ID and 11/16 OD. The desired amount of float or movement would be .070" - .100".

You never want to force a clutch onto the crankshaft. Take the time to make sure there are no burrs and make sure the clutch slides freely.

Light filing of the key, steel wool on the shaft and so on.

Put your clutch on the crankshaft (inboard or outboard), then place the washers on the 5/16 bolt. Torque the retaining bolt and make sure the clutch still slides freely. Position the clutch halfway between the crankshaft step and your 1 1/8" flat washer.

To get the benefit of clutch float you need to make sure it is centered on the crankshaft at this point. Align your rear sprocket with the clutch sprocket while centered. The clutch isn't going to move back and forth unless need be.

The flat washer that you hold the clutch on with should be 1 1/8" in diameter and the length of the 5/16" bolt should be 3/4" long. Tighten the 5/16 bolt snugly. You do not need to over tighten as it will make removal more difficult.
 
#16
My son and I finished up his Doodlebug. He loves it! He is very proud of it and I can tell he appreciates it much more due to the amount of wrenching he put in on it. It has a very nice amount of power. No trouble climbing up inclines. Top speed on level road is 34.3 mph. The long hill he used to have to get off and walk it up after about 1/2 way he now tackles with ease. He has taken it on several long rides with no issues. Farthest ride was about 5 miles round trip. We put the muffler on because he does ride in to town with it and the straight pipe was too loud for that. He was a little bummed out about that, but it still sounds sweet! I made sure it was screwed on "Dad tight" to keep him from removing it. This was a ton of fun to do and we are actively looking for another mini or a kart to build.
What we did and where it came from:
HARBOR FREIGHT: 212 Hemi predator. OldMiniBikes WAREHOUSE: engine mount plate, air filter kit, clutch cover, carb jets (running with a .036), hydraulic brake, chain, 14t max torque clutch, breather filters. HOT ROD MINIBIKE: header and muffler. AMAZON: 6ply tires, front and rear bearings. We also used a conduit bender to bend the handlebars forward. Worked perfectly.
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#18
I have one, and I've done many of the same changes you have. Those handlebars look way better bent, and they're much more comfortable. Glad it worked out for you. I did the same thing on mine. However, I've also broken a conduit bender trying to do the same thing, too.
 
#19
I have one, and I've done many of the same changes you have. Those handlebars look way better bent, and they're much more comfortable. Glad it worked out for you. I did the same thing on mine. However, I've also broken a conduit bender trying to do the same thing, too.
Hot dang! Broken bender! I just used my Rigid one I use for work. I have bent miles and miles of conduit with it. He does like it much more with the bent bars. No longer has the handlebars 8" from his chest.
 
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