performance and ride?

schwinnrider

New Member
Jan 28, 2008
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phoenix
well i finished my bike a few weeks back it has most of the original parts and gear on it except a 36t sprocket and the baffle cut out of the muffler. well its working good BUT i would like to see if i can get more power from it ( i know it cant be bored ) bit i mean as in exhaust? would a straight pipe coming out the rear like a motorcycle work? enough back pressure?

and also is there anything i can do with the carb? I've herd someone getting an extra 1-2 horses out of these 80cc motors just from doing the exhaust and carb. i have a msd spark plug wire on it so that is an upgrade i have also. so i would just like to know if there is anything i can do for more performance? and i see a few people on here have done some of that work, so any ideas will be awesome.


thx
 

paul

Well-Known Member
Dec 23, 2007
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Re: performence and ride?

another small thing that makes a big difference is change out the plug wire for a good one. the ones that come with some of the kits are junk. of all the performance mods i have done this one thing made the biggest change on my bicycle motor. its also the least expensive change:D
 

Norman

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Jan 16, 2008
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Re: performence and ride?

Do you guys have spark plug abrasive blast cleaner?
I found out that if the plug gets dirty, carbon, oily etc it will run, but not real well, up to the point of dieing and will not start. I found this out playing with my lights the bike ran good with the old lights and I put on the new big light and I start having trouble the bike would run get sort of warmed up, then start acting up. light off ran good, lights on run then die.
I know the wrist pin bushing is going bad along with the spark plug problem.
So I check out the coil it checks out and the plug wire checks out even changed out the plug wire, then I went after the wiring which is inside the frame I figured I got a wire bare somewhere and shorting out. It will run with the light off but not long with the light on.
To make a long story short it was the china plug fouled out I cleaned it with the blaster and it now runs like a champ. I know carbon will conduct electricity. Off the wall, the wrist pin bushing is putting out microscopic particles of brass and the combination of these is allowing the plug to fowl out along with idling it to much playing with and adjusting the light etc.
After cleaning the plug I have yet to fowl it out again. I found out it was the plug by simply changing out the plug. Funny thing the plug that fowled out would show a spark when out of the cylinder and laid against the head, pushing the bike I could see a fairly good spark. Put the plug in the cylinder and no fire. I ran into this years ago with plugs that will fire in normal atmosphere but not fire when under combustion pressures. So next time you have one of your engines not wanting to run change out the plug even if it looks good cause it might not be( but if you blast clean it, it should be good). I could of saved myself a lot of chasing if I had changed the plug or just cleaned it well. So I am still on the original spark plug.
Something else you have to be sure to get all the nasties out of the plug before you reuse it, threads and inside the plug if you don't the abrasives will eat the engine up. I use high pressure air and carb cleaner with a wire pick then clean the threads and a dab of never seize on the threads. Don't forget to gap the plug to your favorite gap.( before you put on the never seize)
Norman
 

thatsdax

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Feb 22, 2008
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Re: performence and ride?

Since these engines already make around 2 hp or so and can propel a bike anywhere from 30-40 mph. If you need more power then you should look into a scooter or motorcycle and getting an M license. Keep in mind that these are motor assisted bicycles. not motorcycles, not scooters, not mopeds. As for ride.. there are lots of things to improve ride quality. Larger tires, less tire pressure, suspension, seat posts, seats , ect... Enjoy the ride...
 

thatsdax

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Feb 22, 2008
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Re: performence and ride?

I am not trying to pour water on the performance fire.. I think performance is very important, I just do not want guys going 50 and 60 mph through town on their bicycles and making cops mad and then they will regulate our hobby or outlaw it all together. Which will not be good at all. Enjoy the ride...
 

Norman

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Re: performence and ride?

Dax
You have hit the nail on the head. I could not agree with you more. If a person wants to go fast get the proper tool to do it with don't try to make a bicycle into a motorcycle. Make the bike you ride as safe as you can and obey the laws. All of us want to have the fastest bike that is natural as most of us are gear heads. BUT! We are going to lose what fun we have if we don't try to police ourselves. My bikes have homemade tuned pipes but they are as quiet as a factory stock I think even more quiet. Mine will go faster than it is safe to ride but i don't go fast I like the lower rpms for cruising. I also have lights. I also try to obey the law and not make people mad.
Lets do the right thing. Want to make a hot-rod that's OK ride it off the road or on a track. When on the street tone it down and don't make people mad. I offer anyone who want to a ride on my bikes a chance to but in a safe place and I give them the low down on what to do and how to do it. A operating kill switch is important and a dead man switch maybe even more so if you let others try out your bike. Looks like I just talked my way into a how to on a dead man switch. Well I'll get off the soapbox and do the chain breaker I promised.
Norman
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
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Scottsville, VA
Re: performence and ride?

An alternative to increasing the HP of the engine would be to use a transmission to give the engine the optimal gear for the terrain....I find that my 36T is a pretty good gear for me but if you are looking for top end Banzai runs the 36T is still a short on the gearing....I can tach out at 6300 or so RPM and only be doing about 34.4 MPH.....I didn't want to push the Dax 70 any further for fear of blowing the engine (sounded rattly)....If I geared up to maybe a 32 T I think it would still do fine of course steep hill and slow speed performance would suffer (I do run a tuned pipe on my bike tho so it does help it up the steep hills when compared to a stocker)......

Gearing can be fairly easily accomplished with the NuVinci Hub system ( I can get you these New for $275 delivered to the lower 48) and a little tinkering in making or finding a jack shaft (the rest or the parts you may need are easily commercially available).

Good luck and ride safe!

Andrew
 

Norman

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Re: performence and ride?

Andy
Right now I'm not sure if we can legally ride and over 20 mph is for sure breaking the law. More than one gear is a no no too. so all the hot rodding will get a guy in trouble. I'm going to look at quiet and easy, smooth riding instead of out running everyone. I also want to be able to go with out tools which so far I have done.
I'm surprised you haven't been nailed in Va. yet when I lived there everything was illegal.
Norman
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
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Re: performence and ride?

Personally I think anything over 35 mph on a bicycle is too fast
...however getting to 35 mph is a different story.;)
 

Norman

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I just put on the 36 tooth sprocket. I fired up the bike and the gps and found that the bike will go at least 38 mph. I pussed out at that speed the fence at the end of the road was coming up to fast as well and the bike was still accelerating and this is going up hill. I will do a how to post on the change out in a little bit nothing new really but you guys might like it. I got the sprocket from a seller on ebay and the center hole was bored off center by 1/8" so broke out the dremel and fixed that before I even tried to mount it. I clamped the 36 tooth to a 44 tooth and scribed the center hole outline on to the 36 tooth to true up the sprocket then ground it out with the dremel. The results were it works great and runs true up and down I have about 0.015 out of true side to side so I can't complain. Now I need to take the engine apart and do the wrist pin. I might take it all the way apart just to see it and to change out the crankcase gasket. We all know how good the china gaskets are. I would like to give it a go on static flywheel balancing as well. So that's where I'm at now messing with the redneck black bike.
Norman
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
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Scottsville, VA
Hi,

They haven't nailed me cause they haven't been able to catch me! ;-)

Truthfully I should probably look into the letter of the law but as far as I know less than 50 CC and maybe no tranny is legal.....Not sure about speed limits (other than not breaking them....which with stock gearing would wind out the engine anyways so I wouldn't do it then....BUT with a NuVinci or my current 36T I can break the 25 MPH residential limit if I wanted to! (so far the fastest I have been with the bike is 34.4 MPH....RPM limited....I didn't to wind it out any more....I think with steeper gearing I could go faster without fear of blowing the lil 70.

I think somebody may have posted the VA laws but I may look into them later just for fun.....

Andrew

P.S. - I did have a policeman comment that the pipe (tuned pipe) was a nice touch when I walked the bike on the downtown mall (police on the downtown mall patrol the mall area via bike).
 

Norman

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Andy
Was 34 mph with a 36 all the faster your bike would go? I could get 34 mph with the 44 tooth and wound out. I used my gps to make sure of the speed.
I got to 38 mph and still winding it out when I chickened out and I was getting close to the barbed wire fence and the end of the street. I'm sure it will go faster but I don't want to until I replace the wrist pin bushing. The bushing is going south on me I found this out while I was taking the engine apart for a top end how to a while back.
Norman
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
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Scottsville, VA
HI Norm,

Wow 34 MPH with the 44?...I think my engine would have blown up by then!.....I dunno my engine sounds kinda rattly that high up in the RPM Band.....27 MPH was as far as I cared to push it with the stock 44....I may go to a 32T shortly but it is such a pain to switch sprockets and cut the chain.

I think something sounds bad in my engine....Actually when the engine is idling (well maybe a little above idling) and I put my hand on the clutch cover case some noises disappear....I may have to peek at the wrist pin one of these days!

Andrew
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
1
18
Scottsville, VA
Oh I put a digital Tach on my engine...The max hold feature shows that I achieved a max of 6300 RPM and the digital speedo showed a max of 34.4 MPH.....I hate to think how many revs you were pulling to go 34 MPH on a 44T....wow ;-)

Andrew
 

Norman

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Andy
I have a tach on my racing kart but I'm to lazy to put it on the bike maybe I should just for grins and yea boy my engine is singing wide open more than likely over 6500 rpms. I must of got a good one or the ports were just right or what little changes I did to it, I don't really know. I put my bike beside Ilikeabika's both kits from the same seller and both are the same size and I can spank him for top end. I know mine revs very quickly this one sounds like a motocross bike engine but I'm not kidding one bit on top speed I used a garmin gps and that is what it recorded for a top speed on all the testing. This engine is the one with the wrist pin that to me looks like its about to turn into a universal joint very sloppy on the wrist pin. The cylinder clearance is very tight I don't remember right now but its listed on the tear down post. So I need to repair it before it spits its guts out I don't want to loose this engine to the God of speed. Wish we lived closer I would sure let you try it out. This Bicycle scares me when it goes that fast I have too many things racing through my mind about whats going to fail and how bad its going to hurt when I start eating the pavement because the bike is being pushed beyond that its designed to do if you know that I mean. I do like the just off idle cruising around 15 to 20 mph. which I think is just right on the bicycle. If I want to go faster I'll ride the Harley which does not scare me going fast on like the bicycle does.
Norman
 
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Ilikeabikea

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Jan 27, 2008
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Norman is right about how his bike engine will wind up. I thought mine was winding up pretty tight but his takes it to a whole new level. Mine will wind up so tight I'm afraid it's going to come apart. But you never know for sure about Norman. I always thought he was doing top secret things to make his go faster. But I actually think he's into voodoo.rotflrotflrotfl
 

Norman

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Well I never gave that a thought. But maybe that is something to try, a little chicken blood in the tank?!:confused:
I wonder how a guy would make Hydrazine?rotfl aka a type of rocket propellant.

I know when I do the wrist pin I'll carve a pentagram into the pistons top and ride the bike backwards. I feel like I'm on a different forum all of a sudden I hear dogs barking!!!!rotfl
Norman
 
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