Digi speedo tripping out when engine runs

[RMWdave]

i did a bit of searching and found out that the magnetized such and so forth of my engine is what does this, so. .... is there an easy fix? id like to know how far im going and so on and plus it would be nice to know the speed im going!

does something need to be grounded somehow? is it hopeless? i know i read about people using them on here during my searching but i cant come up with much in terms of runnin er right... help appreciated mucho:helmet:

 

[Porkchop]

I have a Schwinn computer that cost $10.00 at Walmart. No problem. It works just fine. As cheap as these things are, you might try a different brand or maybe another one like you have might work fine. Could be just a glitch in your particular computer. Just a thought.

 

[Heathen]

Hi!
I had the same problem intill i change my sparkplug to a R marked one (R stands for resistor) if it is a ht 2 stoke engine try running NGK BR5HS / BR6HS or a similar plug.

 

[Shadeslay]

Change your plug wire. SBP has one http://sickbikeparts.com/catalog/product_info.php?cPath=22&products_id=39 or you can go to an auto store, 7mm wire I believe. You may also need to move your speed o depending how close it is to your kill switch or cdi.

 

[RMWdave]

ah so its most definitley electrical interference. thats good to know. i have my speedo wire tired right beside the kill switch wires. i will try moving them away from there first. Why do you think i should change the plug wire? the better plug sounds like a good idea, i will try that. (in the word of 2 stroke lugg motors where low rpm chugging is bound to be enoyable, fouled plugs do often occurr. (and an easy fix for this? carry a soldering torch and burn the plug end off after you foul it! it will work great in a pinch. i used to foul the plug in my tri moto all the time in the woods!))

thanks for the help! and if you can explain why i should change the plug wire that would be great i dont really see any point in modding as of yet but thank anyway

 

[RMWdave]

* also, for those of you who run the SPB shift kit, can i use it just for the jackshaft factor on a single speed? i almos twanna go and buy another bicycle to do up because untill i got the engine purchased and the bike and all i never knew about the site and the aftermarket parts at all. jackshaft and freewheel crank are definitley a must as far as that nasty little tentioner roller the HT kit provides.....

 

[Shadeslay]

The wire because that's where the majority of interference will come from and has worked for many people. It's a really simple fix, the wire just unscrews from the cdi. Can't hurt too upgrade your plug if you are running stock, your engine may run better.

The jack shaft you could use with out gears. But really wouldn't be worth it in my opinion. There's plenty of tensioner mods out there. Or even ways to do away with the tensioner. One method is using 1/4" spacers on the rear engine mount.

Edit: thread on engine shims to get rid of the tensioner, starts at post 9, last post has pics.
http://www.motoredbikes.com/showthread.php?t=5585

Here's another thread on the speed o issue.
http://www.motoredbikes.com/showthread.php?t=14512

 

[RMWdave]

so when i go down to the parts store i need a fatter wire and new cap eh? should i state that it has to be rf shielded wire?

 

[Shadeslay]

Depends on your cap setup, you may be able to use yours, but they are pretty cheap. Can't hurt to ask for a shielded wire, 7mm is the right size, but 8mm will work if you trim down the outside so it will screw onto the cdi.

 

[RMWdave]

ok thanks. question solved for now that sounds like its whats needed. i figured it was either needing a ground of was magnetic interference to begin with!

on a side not to anyone else reading this, get rid of your chain tentioner, mine just upside-downed and pulled the spoke nipple right through the rim. *******it the fix for this will obviousley be a smaller rear sproket (yay more speed)