dumbfounded newbie here in KS

[wichita jim]

I just finished my first ride on my winter project of installing a 2 stroke 48 on a Walmart variety Schwinn cruiser bike.
Luckily I didn't have any major problems but I have tried to be careful and quite a bit of reading the manual.
I may have jumped the gun by installing a Schwinn performance computer/speedometer.
I thought an odometer/trip meter would be great but I'm having problems.
That is what prompted me to try the internet for a motorbike forum...
I am thrilled to find this one.
It works fine pedaling the bike around (no fun lol), but it gives random readings once the engine is started.
The bike can be moving or stationary. The readout can be removed from the mount and handheld and it still picks up interference.
Am I fighting a loosing battle or does anyone reading this have any suggestions?

 

[Jbomb]

Is the computer wireless, or does it have a wire from the unit to the sensor? I tried a wireless one, and it did the same thing you are describing. I replaced it with a computer that has a wire and it worked fine when the bike was running. Good to see another builder/rider in Wichita!

 

[GearNut]

The bicycle computer is receiving interference from the engine's ignition system.
Try as Jbomb suggested. For some a wired version works well, for others it makes no difference.
Another thing you can try is to mount the CDI box onto the seat post tube.
Try to get it as far away from the bicycle computer and wiring as possible.

 

[wichita jim]

Yes, thankyou.
It is a wireless and I am positive it is picking up the CDI box.
I am going to look into wire type options.
I wasn't too happy with it anyway because the LCD face is hard to read... depending on the lighting.

 

[dodge dude94]

I've got a Schwinn wired computer and it works just fine.
Sometimes it catches a stray signal and freaks, but it's pretty reliable.

 

[wichita jim]

Thank you for your input dodge dude94.
I went around to a few bike shops today to ask their opinions / suggestions.
One person said he has spoken to several motorbikers with same problem...
I was pretty much told no bike computer - even the wired ones work 100% right around the ignitions.
Some said learn to live without a speedo and only one suggested an old style mechanical cable drive.
I'm just gutsy enough to try a wired one while keeping my eyes open for a cable driven.

 

[wichita jim]

Well thanking everyone for their help and inputs.... Last night I went to my favorite after hours store wally world and they did have a wired type Schwinn computer. Today after it dried out a bit I removed the wireless one (maybe it will work on my wheel barrow lol) and tried the wire version. It seems to work fantastic. Yippee.

 

[KCvale]

Well thanking everyone for their help and inputs.... Last night I went to my favorite after hours store wally world and they did have a wired type Schwinn computer. Today after it dried out a bit I removed the wireless one (maybe it will work on my wheel barrow lol) and tried the wire version. It seems to work fantastic. Yippee.

Funny how the term Wally World (from the old Chevy Chase Vacation movie) for Wallmart took hold but ya, any high voltage unshielded wire like a spark plug wire will cause radio inference, but one thing is for sure, put a nice fat braided copper spark plug wire on and though it will screw with anything electronic around you, you will feel the difference between some carbon fiber conductor and real copper in performance in the most important wire of all ;-}

 

[wichita jim]

Yes the term has stuck with me over the years lol.
Thank you for the copper wire suggestion.
I am sure I would enjoy the extra performance boost, so I will surely try a better plug wire. That is one of least expensive things to play with.
If I get too much rfi then I will also try a grounded braid to shield the plug wire and boot.
I have trouble logging out of the forum because all of you have so many hints and kinks.

 

[2door]

I'll just slip in here with an observation. Wally sells two types of wired speedos. One is the Schwinn brand, usually the 12 function version, and the other is Bell. I've used the Schwinn on several bikes and only one gave me a problem until I moved the CDI to the seatpost, far away from the speedometer head.

The Bell however will not work on any motorized bike. It resets itself as soon as the engine fires and I've tried every fix in the book without success. I stuck it on my wife's pedal bike and that's where it stays. Works fine there.

Tom

 

[wichita jim]

Hi Tom
Reading your post I am really glad I did choose the Schwinn over the Bell. Thank you.
Both brands were on display.
I personally liked the Schwinn's cosmetics and selected one.
I installed it yesterday and gave it several test drives.
It seems to work great.

 

[2door]

Good to hear that Jim. All of my Schwinns seem to work fine.
I'm not as interested in the speed function as I am the odometer. I like to see the miles accure. The higher that number the better I feel about my building skills

Tom

 

[wichita jim]

Tom That is encouraging to hear about your good experience on all of your Schwinns.
My Schwinn has coaster brake and it didn't work good at all at first but I guess it needed broken in.
It is doing better now but still isn't as good as my old New Departure was (when I was a kid).
I think I would like to add a hand brake to the front wheel but have not looked into it yet.
Thanks for your input and comment.

 

[KCvale]

Tom That is encouraging to hear about your good experience on all of your Schwinns.
My Schwinn has coaster brake and it didn't work good at all at first but I guess it needed broken in.

Tom's comment is not about a Schwinn bike, it is about their electronic speedometers ;-}

Personally I like analog speedometers like this.

~$25 at a bike store.

They are not as accurate as a dialed in digital they are a heck of a lot easier to read at a glance especially in bright sunlight.

Jim... an NGK BPR7HIX Iridium spark plug will give you way more of a performance boost than a copper plug wire, that is low on my list actually.
#1 is replacing the crap motor magneto to cdi wire with double insulated 16g and every 2-stroke I build gets that.
#2 is the Iridium plug which half the time I include free anyway, on all 2-stroke shifters anyway.
Do those first two and the plug wire is far less of a factor, kind of like using a thinner head gasket for a bit more compression or some other motor mod which wouldn't work as well without those 2 steps first anyway.

And YES! Put a front brake on! Riding any kind of motorized bike with just a coaster brake is a cheap preventable accident just waiting to happen.

 

[wichita jim]

KC I do like the looks of that analog speedo.
I will probably stick with the wire type digital - at least until plug and wire get changed.
Right now I am concerned about what I may run into adding the front brake to this bike.
Thank you for your input. Everyone on here is so helpful

 

[Mr. OrangeConeRacing]

The only thing you will run into is better stoping distances insted of the car that pulled out in front of you.

 

[KCvale]

Right now I am concerned about what I may run into adding the front brake to this bike.

Show us of pic of your front fork from the font of the bike.
If there is a hole to mount a fender you have a hole to mount a side pull brake and as mentioned there is no brake mounting problem harder than hitting pavement because you couldn't stop fast enough.