My First Big 4 Stroke- Dupor 196cc Build

GoldenMotor.com

corim123

New Member
Oct 20, 2011
29
0
0
georgia
So I'm ready to move past my runs with 2 strokes and join the world of the 4 stroke. I've got a Schwinn Searcher that looks up to the task and should definitely have enough room to fit this engine. It is aluminum so I'm not sure about welding it or how exactly I'm going to do that so far. I plan on purchasing the $200~ build it dupor that has some upgrades and also buying a #35 3/4" CVT. I'm not sure if I'm getting a jackshaft for further gear reduction or just a massive sprocket yet. Also need to look into exhausts and a disc brake kit. I plan on swapping the rims for some higher density ones and otherwise I'm not really sure what else I'm missing or how to go about this. I hope to order the engine by Monday and have it assembled by next weekend. Hopefully I'll have ordered my CVT and other parts by then and I'll know if this Schwinn will work if I'll need to go find another bike. Let me know if you've done a large engine build before or have any ideas on how I could mount it I'd appreciate it. I know I need a billet flywheel, but I intend to take it gentle at first for break-in and take it easy until I can afford one. I'm really hoping to keep this under about $500 if I can use this bike.
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
Oh I certainly have been, especially at cobrafreaks and scottos. Hopefully I'll order the motor on Monday as planned so I can get it assembled by the time I have the rest of my funds for that.
DJ-1006 Dupor Box Stock U-Build-It Engine Kit
Box Stock U-Build-It Engine Kit ARC DJ-1006
GO KART TORQUE CONVERTER CVT CLUTCH REPLACES TAV2 TAV-2 COMET 30 218353A 203814A | eBay
U-build it Kit Clone Dj-168F [DJ-168FK1] - $199.95 : EC Distributing, Your Online Racing Store!
Are there really any differences in these motors? I know I'll need to get some billet stuff in the future, but for right now I think one of these will be fine. Do I really need another upgraded connecting rod or do these enhanced kits already account for that? Want to make sure I get all the parts and that I don't skip over something and blow it up. I have a budget but if I really need to get other parts I can just delay the assembly and running of it.
***
Also would a mounting kit like this:
http://www.bicycle-engines.com/vframe-mounting-plate-p-105.html
Even work with such a massive motor? Seems like it would be the best way to get a solid mount. I'm used to drilling a hole in my old 2 strokes and they're still holding up after a few years.:)
 
Last edited:

corim123

New Member
Oct 20, 2011
29
0
0
georgia
Alright Dupor engine has been ordered. Hopefully I'll be setting that up in the next couple days. I've also scored a tav2 cvt 3/4" with 10t sprocket for $120 shipped. Might grab a micargi rover for $125 from a friend if it will accommodate te engine. I feel like steel would be better than aluminum.
 

professor

New Member
Oct 14, 2009
500
1
0
Buffalo ny area
I am glad you are going to a steel frame.
Vibration is a big issue on these engines. I have a hf 212 on bike 2 and it vibrated seriously. Ordered a Dupor and put it on instead and it vibed just as bad. Put it back in the box (spare motor?) and isolated the HF with rubber mounts.
I suspect vibes are directly in proportion to piston size.

The gokart stock class clones have no issue with the flywheels as long as the valve springs remain stock (this limits rpm to around 5000- for more info go to www.karting.4cycle.com I spent a lot of time there). I think the better flywheel would be a good idea though, sure would feel safer.
The better rod is needed for high rpm, an item you don't need if you leave the cam and springs alone. A re-jetted stock clone is good for 9+ hp when it can breathe properly, meaning a free flowing exhaust and intake. Lots of torque stock.

Gas milage has been real good because the engine is loafing most of the time.
I really prefer to use the governor, with it screwed as high as it will go (about 4 grand) but the Dupor has no provision for one.
These are sweet motors as far as reliability goes, however, the gokart people take them apart to make sure they are assembled right and assume this to be standard proceedure.
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
I'm also going to have mine apart as I got the U Build it setup with some performance parts. The billet connector will be my next priority after I get this squared away and running. From what I've been reading a billet flywheel is far less important and has perhaps been over emphasized. Any idea if that bicycle is going to accommodate the engine?
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
Looks like I'm back to the aluminum bike unless I can find a better candidate around me. Going to upgrade to 11 guage spokes, seen some made by huffy that are fairly cheap and are looking pretty sturdy. Still trying to determine optimal gearing.
 

culvercityclassic

Well-Known Member
Sep 27, 2009
3,115
177
63
Culver City, Ca
Check out this post: http://motorbicycling.com/f37/felt-racer-34476.html

This bike you are building better have good equipment or it will not last; your motor choice is no BS and will destroy most bike parts. Trust me I have gone thru a few and seen the belts let loose on the CVT, the bike is hard to control when this happens. The last you want is to get hurt...

I hate to say this but whenever I hear Huffy or Wal-Mart I cringe cuz I know the quality is not there...please make better choices for your build....
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
Going to buy more upgrades for the engine so I don't blow it, i.e. Honda piston head/rings as well as an even better cam with a billet connector. Still need to find a bike and I have some unused parts for sale in the parts forum.
 

culvercityclassic

Well-Known Member
Sep 27, 2009
3,115
177
63
Culver City, Ca
Going to buy more upgrades for the engine so I don't blow it, i.e. Honda piston head/rings as well as an even better cam with a billet connector. Still need to find a bike and I have some unused parts for sale in the parts forum.
I see you are still looking for a frame? Whats the status of this build. The motor you have should be fine with-out any more upgrades...so you can save a buck and put it towards a nice frame....wee.
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
Need to get that connecting rod beefed up a little bit. Might as well do this before the engine has been started up and run. Also still need to see if I can find a cheap mounting plate of some sort that would be bolt & weld friendly onto a frame. Also need a jackshaft due to engine mounting position and for gear reduction. Another thing I need to account for now is the exhaust as I have nothing in that regard. I'm still keeping my eye out for a good deal on a solid frame around me. Still on budget so far just trying to get as many parts as I can asap so I can get this together in the next couple weeks and go about seeing if I can get it registered.
 

corim123

New Member
Oct 20, 2011
29
0
0
georgia
I've found a beautiful black electra cruiser. Looks to be the perfect size as well as durability. Just a few more things I mentioned above to sort out and assembly can begin.
 

truckd

Well-Known Member
Oct 19, 2010
2,837
134
63
palmdale calif
Just throwing my 2 cents in but go to bikebuyers.com and check out the Macargi Huntington streatched Beach cruiser, a really high quality bike with Old School Schwinn quality, the frame is big enough that if any mods had to take place they would be minimum as the frame is pretty roomy(being an over sized frame) if you've never seen one go to the thread on this forum titled Ol' Blue and take a look at my bike, don't get me wrong Electra is a fine bike too but very pricey!! the Marcargi is $169.99 + $39.99 to ship and no sales tax, I got my bike in two days and will buy more of these bikes in the future with perhaps the Dupar 196cc to fit insde.
Good Luck in your quest