Pocket Bike Engine Project

[lowracer]

I took it for several WOT blasts & over some bumps in the road & it didn't slip.
Since yesterday I replaced the small canister muffler removing the expansion chamber pipe. The difference in top end is noticeable but not too drastic & I dont plan on cruising on this 'Banshee' as often as the 'The Beast' (Tanaka powered).
I ordered & am waiting on a new DAX friction drive unit to turn the beast into a front wheel drive v-belt system (again). Will slide the roller off & mount a 1.5" OD, 5/8" bore pulley.
-Lowracer-

 

[lowracer]

Today I got all p'd off @ the Cag engine & am done with them for good.
The pull starter rope broke (again) & it vibrates too much (into my seat).
I installed the Tanaka 40 & rode it around.....ahhhhh such refined bliss.
I boxed up the cag with the two others I've accumulated & wont be mounting them ever again. I ordered a Tanaka 33 (had one, sold it on a bike, but loved it) & will either mount it to the front of 'The Beast' or to the back of 'The Banshee'...Here is the latest pic
-Lowracer-

 

[happycheapskate]

I agree, the Tanakas are so sweet I am spoiled forever against any other engines.

Join Dax Friction Drive Fan Club please! I featured your bike.

I found this for you. Privee Production small-company built direct bolt on stem and bar combo, bolts onto triple tree fork clamps, not the steerer!

http://sadpanda.us/images/1172180-S6XAHK5.jpg

Today I got all p'd off @ the Cag engine & am done with them for good.
The pull starter rope broke (again) & it vibrates too much (into my seat).
I installed the Tanaka 40 & rode it around.....ahhhhh such refined bliss.
I boxed up the cag with the two others I've accumulated & wont be mounting them ever again. I ordered a Tanaka 33 (had one, sold it on a bike, but loved it) & will either mount it to the front of 'The Beast' or to the back of 'The Banshee'...Here is the latest pic
-Lowracer-

 

[lowracer]

Happycs,
I checked out the fan club & liked seeing my bike, but I dont facebook.
The direct stem is a good idea & my fork has the holes for it, but the Truvative stem that came with the bike is thick & honking & I really like the handlebar position right now.
I ordered another 3" motorcycle bar end mirror & another Radbot 1000 rear tail light for The Banshee.
-Lowracer-

 

[happycheapskate]

That's ok. FB can be annoying so I don't blame you. It's fun for me though.

 

[GEJoe]

I, too, gave up on the Cag engines after replacing the piston and cylinder on my GT50R after the Opti2 ate it up. Then the clutch springs broke (it is still new after a year - less than 5 miles). The friction drive ate my armadillo tires too fast, so I put on chain drive. The chain promptly broke. The head started leaking even after beefing up the head bolts. Boxed it up this spring and went back to my 2005 Golden Eagle with the 25.4 cc Komatsu. I would guess it has about 2000 miles on it after 7 years and runs like new. I know Golden Eagle stands by the Tanaka engine.

 

[lowracer]

GEJoe,
No more Cags! I had the same problems as you plus a few pull starter breakages.
I said I was done with them once before, but then what did I go & do? I unbox it & install it onto my latest project only to remove it once again for good.
They are very powerful, but very unreliable. I now need reliability since I have been using my bike more for transportation (doing my job & riding anywhere from 50-100 miles per day). So far the Tanaka PF-3300 I had, but sold on a hardtail MB & my current Tanaka PF-4000 have been super reliable & very refined. I ordered another PF-3300 for my 2nd MB & it should be here in a few days. Today in an effort to remove the flex pipe from my exhaust system, I flipped the engine up on its side & mounted the expansion chamber directly to the header piece & still use the 2 springs & some stainless steel zip ties to hold the pipe to the springs. I haven't had a chance to ride it with the engine in this configuration, but I did start it up in the garage to see how it sounded....Too much rain lately with hurricane Irene soaking the day.
See pic
-Lowracer-

 

[GEJoe]

What more can I add? You are spot on. My next will be a 4stroke with belt drive only. More than likely the Golden Eagle 4 stroke Subaru on bikeengines.com - Good luck with the friction drive (I do not like what they do even on a wet road, let alone raining, big mess).

 

[gera229]

I'm also in the process of giving up on my cag engine. Seems like there is too much spitting out of it and it is very loud and vibrates lol. The thing is I just don't have the money to buy a good engine now (I wish I never spent over $150 in the cag engine plus parts on it in the first place). For that price, that equals to a good engine except the costs will stop adding up because no parts need to be replaced. So in the long rung a Tanaka might be cheaper.

While my CAG engine is reliable in terms of piston and cylinder and everything else... The only problem is the spring snapping one and that makes a huge difference in riding. I recently snapped a spring (finally) midway home and pedaling was hard because I have a chain drive with a gearbox so it took twice the effort to pedal.

That is the only thing that I'm frustrated about and it's a major problem. Stalling out of know-where as a result of the spring getting stuck in the bell is not cool. Then you have to take out the gear box and take that spring out to let it spin freely again.

If only it wasn't for the spring snapping problem, I would have otherwise kept on riding it especially if I also fixed the fuel spitting problems which I think exist on all 2 stroke engines. Infact since it's all I have for now, I will keep riding it.

For the pull start rope, I got a quality rope and used a tapered punch to punch up the edges of the copper ring on the inside where the pull start comes out of because that was one cause of ripping pull start ropes. Now, so far I have not ripped a rope with this quality rope I put on and it was cheap.

Now about your Tanaka engine tilted:

Why did you remove the flex pipe?
Does this tilt of the engine cause the carburetor to become unbalanced? And isn't that bad?
Does the Tanaka spit as much burnt fuel as the CAG engines spit the black burnt fuel?
Does burnt fuel leak at the tip of the muffler after a ride like you would see if using a CAG engine (I'm pretty sure you know what I'm talking about because especially after long rides like yours you would see this)?

Where you mounted your expansion chamber with springs, did that place where the expansion chamber attaches to the engine by sliding over a head pipe require you to seal it up? Does it leak there?
Does the expansion chamber pipe slide in with a tight fit or did it slide in with a little play when sliding it onto the head pipe?
What did you use to seal it up? (I would suppose it would seal by itself if it was a tight fit where the exhaust pipe had to be pushed onto the head pipe.)

 

[lowracer]

Gera,
Ditch the cag....it will definitely be a problem down the road. It didnt spit too much out of the muffler & when I park it in the garage, I dont get a drippy mess. The carb on the Tanaka is a walbro pumper carb & can be mounted in any position. Many MB'rs tilt them up for better gas tank filling & it also allows the exhaust port to face straight down. Te flex pipe makes the exhasut sound louder than it should (flex means leaks) I've heard it could run a bit richer in this position which would be ok with the modified exhaust. The Tanaka doesn't spit at all (thru the cases) like the cags do. The exhaust fits very tightly over the small header that bolts up to the engine so no sealant is used. I modified a 2 bolt clamp that also has two large center threaded areas for large bolts to press up against the pipe opposite each other for a very snug header to pipe attachment point. Then the springs holding the stainless ties to the lower mounting portion of the expansion chamber in case the clamp gets loose.
I'll take some better pics of the attachment point outdoors when the weather clears up.
-Lowracer-

 

[lowracer]

Here is the thread of my latest project I just completed today. Its a Dax friction drive converted to v-belt drive w/ Tanaka 32cc engine & expansion chamber. Just waiting on the rear view mirror to arrive via mail order.
http://motorbicycling.com/showthread.php?p=421907#post421907
-Lowracer-

 

[zippinaround]

very good thread! have just spent the past hour or so reading through it. i'm planning on building my first motor assisted bicycle using a standard cag and after reading this i think i'll go with a similar setup using belt and rim to rim just wondering if i could do it on the rear wheel or is front easier?

 

[lowracer]

zippinaround,
I've done it on the rear wheel too & its just as simple.
The bike kinda dictates the placement & that bike was just easier to do a front rack on.
I have a thread in here with twin engine cags driving both front & back w/ v-belt drive.
Was way too scary.
-Lowracer-

 

[lowracer]

Here's that thread.
http://motorbicycling.com/showthread.php?t=35012
-low-