POS cb125 bucket

**wbks** · 29th January 2009, 15:24

New fully charged battery, gets spark as it turns over. Trying to push start it but it just goes "put put puuuuut puuuuurmmm" and doesn't make any effort to take off. Tryed starting it in first and second but same thing. What are the things I could be doing wrong? The little idle screw thing isn't set but I can't tell how to set it untill the fucking thing is running. Full choke,half choke, no choke, works better on full choke but still, nothing. What's wrong with it? Was running before I put the new battery in but like I said it's getting a spark. This thing is pissin me off, blows coil-new coil, plug, battery and now it wont run. someone must have some suggestions? its getting vewey vewey agrivating trying for an hour at a time on seven different days coming back dripping in sweat from pushing this pig up and down the road jumping up and down on it but still no life

**koba** · 29th January 2009, 18:00

6 or 12 volt....

Or a mix of both...

Get a manual and read it, it will tell you all you need to know.

**speedpro** · 29th January 2009, 18:29

I love it. The bike is a single cylinder 4-stroke with two valves and points ignition , , , , , and you can't get it to fire

Even just pouring some gas down the plug hole, screwing the plug in and connecting you should get something if the ignition is firing when you push it. There is some compression? You should be able to connect a timing light, kick it over or just spin the back wheel by hand(with the plug out but in the cap and next to the motor) and check that the timing is in the ballpark. There really isn't much to it. Compression, fuel, spark. You need all three.

**wbks** · 29th January 2009, 19:08

Originally Posted by speedpro

I love it. The bike is a single cylinder 4-stroke with two valves and points ignition , , , , , and you can't get it to fire

Shuuuutup ow... I got it going in 3 pushes the first time it had ran in a year of sitting. Now-nothing

Originally Posted by speedpro

Even just pouring some gas down the plug hole, screwing the plug in and connecting you should get something if the ignition is firing when you push it. There is some compression? You should be able to connect a timing light, kick it over or just spin the back wheel by hand(with the plug out but in the cap and next to the motor) and check that the timing is in the ballpark. There really isn't much to it. Compression, fuel, spark. You need all three.

Compression is fine, its only a couple hours off a rebuild. Heres the thing - Sometimes it sounds like its about to start and turns over but never actually takes off, other times absolutely nothing. And no, there shouldn't really be much to starting it which is what pisses me off. It's had the idle screw played with (not by me) while it was off and I guess that could be it, you think? Either that or the battery wasnt charged enough but I'm sure it was.

Just cut out about 30cm of excess wire and dodgy connections last weekend so I'll bet its a loose connection, but I'll check if it's actually sparking with the plug out now that its dark and I can see

**TZ350** · 29th January 2009, 19:19

Charge the battery.

Battery not fully charged? That makes sense! New 12V coil, New battery but been sitting around for a while. 12Volts on the bench but possibly only 8Volts at 1 Amp left in the battery when the current tries flowing through the coil (usually 12v 2A, but is possably less from your battery if its low).

Not enough flux builds up and when the points open and the field collapses, a weak spark results, and any throttle above idle allows enough compression pressure to quench the spark at the plug gap.

Idles and possibly even runs but any load blows the spark out! possible?? you see this with low battery's at every bucket meeting.

Charge the battery.

Another issue you could have is with the condensor.

Kick the bike over and look at the colour of the spark, phat deep blue = OK, skinny blue/yellow = weak, yellow = piss weak and won't run anything.

**SHELRACING** · 29th January 2009, 19:22

Originally Posted by wbks

Shuuuutup ow... I got it going in 3 pushes the first time it had ran in a year of sitting. Now-nothing

Compression is fine, its only a couple hours off a rebuild. Heres the thing - Sometimes it sounds like its about to start and turns over but never actually takes off, other times absolutely nothing. And no, there shouldn't really be much to starting it which is what pisses me off. It's had the idle screw played with (not by me) while it was off and I guess that could be it, you think? Either that or the battery wasnt charged enough but I'm sure it was

Is it a twin or single... Whole load of could be's

If you stripped it down did you get your valve timing correct. The twins can be a pain in the ass.

Is it Total loss or the original ignition system. Old hondas ran 6 volt systems. Useless... Convert to a simple 12 volt total loss system (make sure your coil and battery are 12v).

Make sure the battery is Fully charged. Especially on a total loss system. A slight drop in battery voltage and you ain't goin anywhere. Get youself a volt meter. If the battery is old it can shown 12volts, but drop to 10 -11v when plugged into the bike, which is not enough for good ignition

Get some easy start from supercheap and give it a squirt

**Ixion** · 29th January 2009, 19:24

Doe sit not have a kickstarter?

As the rapid gentleman noted , they are hardly complex engines.

Assuming compression, and that you have actually seen it run properly(and thus the engine is assembled more or less correctly), and the carb not monstrously deranged, it must start. If it has a spark. You have not timed it on the exhaust stroke? I don't think that is possible on those motors, but it's been many many years since I woned one.

They should start immediately, just flicking the kickstarter with your hand.

What does the plug look like? Dry? Fouled?

EDIT: They will start without a battery, with a good push, but run erratically. Unless you put a big capacitor in the circuit.

**wbks** · 29th January 2009, 20:22

Originally Posted by Ixion

Doe sit not have a kickstarter?

As the rapid gentleman noted , they are hardly complex engines.

Assuming compression, and that you have actually seen it run properly(and thus the engine is assembled more or less correctly), and the carb not monstrously deranged, it must start. If it has a spark. You have not timed it on the exhaust stroke? I don't think that is possible on those motors, but it's been many many years since I woned one.

They should start immediately, just flicking the kickstarter with your hand.

What does the plug look like? Dry? Fouled?

EDIT: They will start without a battery, with a good push, but run erratically. Unless you put a big capacitor in the circuit.

It's total loss, won't run. It sounds like not enough gas is getting through but it has to run on full choke or else the wheel stays locked up and wont turn over. I haven't touched the timing since I had it last running and it ran great. The battery is a 6 volt through a 6 volt coil, and has about 4 hours charging on it. I'm not sure how long they need to charge for but if the amount of battery charge has as much of an impact as shellracing said, it might just not have a strong enough spark. I accidentally grabbed the plug as it clicked over and it gave me a strong pulse through both arms so I would argue it's charged haha. I'll leave it over night which will be all the possible charging it can take but if it doesn't go then I have no idea what's wrong with it. It still feels like it's just not getting enough spark, which is something I cant fix because I haven't touched anything on it since last time...

I was under the impression that the amount of power in the batt didn't have any affect untill it is near flat, I mean how much spark power do you need?

Plug was dark but now looks fine, kickstarter removed. I guess I'm just trying too hard if it takes a long time to charge the battery. How long does it take?

**Ixion** · 29th January 2009, 20:32

Um, I know this is a REALLY REALLY REALLY silly thing to say, but - it's not out of fuel is it?

**wbks** · 29th January 2009, 20:35

Lol, nah, I did change the way the fuel line was so that was the first thing I said but every couple push's I check the float bowl and every time it's as full as ever, so it's getting to the carb fine

I guess the only thing is spark. I still think that 4 hours charging a little 6 volt should be enough though, but probably is what's stopping it so maybe not

**koba** · 29th January 2009, 20:38

Originally Posted by Ixion

Um, I know this is a REALLY REALLY REALLY silly thing to say, but - it's not out of fuel is it?

It is never a silly thing to say!

Also is it GETTING what fuel is in the tank (if there is any)

Refer to speedpros advice above, whack some fuel down the plughole and try again, if it splutters it aint getting fuel.

A recent engine rebuild is a good reason to look at everything, as things do go wrong and the first kays on a fresh engine are delicate ones.

**wbks** · 29th January 2009, 20:44

It's not exactly fresh, it had a race day on it already so it should be fine. Won't putting fuel into the cylinder be pushed out the exhaust by the time it starts turning over? If it was kickstart it could be noticeable but I'm pushing it up and down the driveway so it could be hard to tell if it turns over once or not. When it was running it would still do what it is now, only eventually it would just sort of start firing after a second of bump starting but now nothing. Still probably weak spark.

**koba** · 29th January 2009, 20:57

Originally Posted by wbks

It's not exactly fresh, it had a race day on it already so it should be fine. Won't putting fuel into the cylinder be pushed out the exhaust by the time it starts turning over?

No it should work. Alternativley you could dip the plug in fuel (not if it is glowing hot of course!)

You should be able to tell if it starts to pick up as it will cough and splutter.

The idea is to completly eliminate two of the three possible problems beyond a doubt so you don't piss about looking at the wrong bit.

**wbks** · 29th January 2009, 21:00

Dipped the plug in gas and it tuned over a little better ( I mean the piston revolved, it didn't sound like it was firing ) but that may have just been me, I was trying to push it a lot faster. So basically gas on the plug made no diff. I guess that makes it certain it is lack of battery power?

**koba** · 29th January 2009, 21:07

Originally Posted by wbks

Dipped the plug in gas and it tuned over a little better ( I mean the piston revolved, it didn't sound like it was firing ) but that may have just been me, I was trying to push it a lot faster. So basically gas on the plug made no diff. I guess that makes it certain it is lack of battery power?

Now that is somthing you will have to judge!

So is the spark good fat and blue?