Help with intermittent starting on Motorbike

[miketrev]

Hi All, As you have guessing Im quite new to this forum. I haven't has a chance to introduce myself but I do have a question (Not good on my first post I know). We'll I'm Mike and I'm from Sheffield in the UK. I have recently purchased a Pulse Adrenaline 125 and I bloody love it.

http://www.mtrevor.plus.com/mebike.jpg


I was wondering if anyone can point me in the right direction. I have a Pulse Adrenaline 125, last night I changed the speedo drive.

Afterwards when I tried to start the bike its doesn't start. The strange think is, when I put the bike on a uphill angle it started, downhill angle it doesn't. When it does start, as soon as pull off it stops. I was suspecting maybe it was a vacuum issue, but when it does start it will stay on. I have had it running for 5 minutes, but as soon as I set off it cuts out. I have checked for spark on a uphill angle and there is one single spark when I first turn the engine over, but its doesn't repeat. A friend said this is normal, can anyone confirm this?

I did drain the front brake fluid when putting the front break disk back on, do you think this would have anything to do with it? I'm thinking is there possible a sensor inside the brake fluid reservoir.

I did have a slight "mini-drop" when I was putting the front wheel back on, The toolbox the bike was resting on collapsed, the bike didn't fall on the floor but it dropped rapidly for about a foot, no visible damage was done and I really didn't think much of it. I have been suggested I may have disturbed something in the carb and need to dis-assemble, clean and check the floats, does this sound correct?

Can any suggest what steps I should be looking at in order to resolve this.

Few points.....

This bike doesn't have a side, so its not a faulty switch.

I have checked the fuel flow to the Carb and that seems fine.

The vacuum pipes all look OK

[Weldangrind]

Welcome Mike! Nice looking machine. 8)

It sounds like a simple float adjustment is in order. To me, the key is the uphill / downhill symptom. Remove the carb, turn it upside down and remove the bowl. Hold the carb up at eye level (still upside down) and view the parting line of the float; it should be about level with the aluminum base of the carb.

Scroll down to the pic on page five: http://www.chinariders.net/modules.php?name=Forums&file=viewtopic&t=8928&start=60 Different carb, but same idea.

FWIW, I can't imagine that there is any sensor at the front brake.

[miketrev]

Thanks very much for your help, ill give that a go and let you know how I get on :d

[miketrev]

Hi All,

I have taken the carb apart and the floats moves fine, has no leaks and looks parallel to the bowl. The jets look fine and can see daylight through them. There was a small bit of gunk at the bottom of the bowl which I have removed. It's now re-assembled but the problem is still there. I think Ive checked all the fuel related stuff, which leads me to suspect it may be something to do with the electrics.

Can anyone confirm if when turning over the engine, the spark plug is supposed to spark multiple times and not just once. I am reading in the Haynes manual "If the system is good condition a regular, fat blue spark should be evident at the plug electrodes" which its not because I only get 1 single spark each time I try to start it. The engine keeps on turning though. I have tried a new plug and it does the same. I had a freind tell me that some bikes only have a single spark from which it starts and it will then produce more, is he fibbing to me?

Once again, thanks again for your help

EDIT: Update, I have just started it again and the spark happened multiple time, put the plug cap on the plug and it started! Its not only doingit a single time again now though so Im guessing it must be electrics.

[SpudRider]

Welcome to these forums, Mike! Your bike looks great! :)

Indeed, you should get a steady stream of sparks from your plug while you are cranking the engine. I suspect you have a dirty starter switch. ;) I suggest you disassemble the starter button, and clean it with contact cleaner. :) If cleaning the starter button doesn't fix the problem, I suspect you have a bad CDI unit. ;)

Spud :)

[Weldangrind]

My guess is the plug wire. If you peel back the boot at the coil, you can unscrew the wire from the coil. Similarly, if you peel back the boot at the plug end, you can unscrew the plug end from the wire. Both ends are really tight, but they unscrew. Once you have the ends off, measure the plug end with a multimeter and see what the impedance is. Then, check the wire for continuity. If all is well, cut 1/2" off of each end and firmly re-install.

Hopefully, a nice free fix.