Bike won't start :(

[sham]

Hey guys, so the CDI's been in and gives off a tiny spark, the tank was cleaned and petrol had been added...I expected it to start but all I got was the usually starter whirrr, plus a new weird gassy sound from the exhaust (in my head its kinda like one of those supersonic booms but much less impressive, but that kind of "puff")...


I kept my hand on the starter, and just after the video was taken, it literally sounded like something in the engine gave way - some kinda metalic clanking like a chain snapped or a bolt fell off...


So I haven't opened up the engine to check anything, I've kinda just stepped away and I'm not quiet sure what to do - would anyone be able to suggest what might be wrong?


http://s1139.photobucket.com/albums/n560/shamjay/?action=view&current=4616e55e.mp4

 

[hillsy]

Does the engine still turn over? Might have been a misfire / backfire kicking back on the starter gear (that can sound pretty bad, but not necessarily do any damage).


Also, doesn't seem like your engine is turning over very fast - is your battery fully charged / in good condition? A weak battery will turn over the motor but not have enough power to provide a decent spark.

 

[sham]

12.23V at the battery without turning the bike on, and the engine still turns over...definitely doesn't seem to be a loose bolt or anything - can't find anything around the proximity...

If it is a spark issue, I was thinking the spark looked pretty weak after installing the ignition module - video below.

I tried starting the bike again just then and the same sounds are happening, but the petcock was in the off position. I haven't actually tried starting the bike before today, so is it possible that this is just what happens when no petrol is going through the engine? The petcock was on for the earlier video, but I'm just wondering if the issue is that its not reaching the engine.

I've also noticed that the rear right indicator is not working again - this was an issue when I was running the 15A main fuse instead of the specified 20A. I didn't check it after installing the new ignition module - is it possible that I actually need more amperage than specified? Or is this somehow related to the bike not starting?

Thanks.

http://s1139.photobucket.com/albums/n560/shamjay/?action=view&current=3703fb78.mp4

 

[sham]

Well I thought it might be something simple like no petrol getting into the carbs, but I checked the hose going from the petcock to the float and there was petrol from both ends - so I guess the plan is to take the carbs out again and see if petrol went through it (?) and then if there's evidence that it has (I'm thinking there'll be some fuel in the main chamber thing where the butterfly valve is) then I'll have to crack open the engine and see what's going on in there...

Is anyone able to advise on the state of my spark incase that is the issue? Or does anyone have any other suggestions on how I might look for the problem, or know what the problem might be?

Thanks.

 

[hillsy]

A fully charged battery should sit at 12.8 volts, so yours is a little low. Some bikes need a fully charged battery to crank the motor and still have enough power to provide an adequate spark. Try jumping the battery off a donor and see how that spins the engine.


But first, unscrew the drain plug on the carb float bowl and check you are getting fuel in there.



Just looking at your spark video, the spark looks OK (well, it looks strong enough to fire up).

 

[frogman]

My old 360 will make a chain sounding clang when I get a half assed start, that is just the starter spinning backwards.

Spark looks fine, you want nice and fat blue/white not skinny yellow. Is the bike timed correctly, set according to manual?

Fuel, do as hillsy says, turn petcock on, give it a few seconds then place a catch cup under the carb and turn the drain screw on the bottom of bowl. Some carbs dribble out of the bottom of the bowl, some dribble out of the overflow tube under the bike. If you are getting fuel then yours should start pissing fuel from one of the two places. IF it doesn't take a soft handled screw driver handle or hammer handle and tap on the bottom of the bowl lightly, sometimes the floats will stick in a closed or open position and a slight rap one the carb will loosen them. You said the tank has been cleaned, have the carbs? I have a set that sat for around 10 years and the floats are stuck solid in the bowls.

The signal is another issue, possible loose wire or bad bulb.

And there is no need to pull an engine apart that is otherwise working, once to taken apart, they are never the same once you put them back together. If anything beg borrow or steal a compression tester and check yours.

 

[sham]

I actually haven't checked the timing according to the manual - wasn't even aware there was such a section, so I'll have a look into it. The carb was the first thing I cleaned when I got the bike - having said that I really didn't have much of an idea as to what I was doing and ended up removing the brass (?) coating on the drain screw, so perhaps I did more damage than good.

Thanks for the direction, I'll check the carbs and report back tonight. Probably won't be able to get my hands on a charger till the weekend, so I'll start from there.

 

[sham]

Actually, does anyone have any suggestions how to check the timing? The manual says that I should be using a timing inspection cover (special tool), and that the bike should be at at 2,100 rpm and 4,500 rpm respectively for me to check it...

Looks like the float is stuck then - I checked at the petcock and there was definitely fuel coming out, but when loosed the drain screw nothing really happened - I got a few drops of fuel and then it all stopped.

But on the other end of the fuel hose (the one that connects to the carb) there is petrol as well, so I think I'll have to dismantle the carb again...is there any reason why the float should be stuck? I did clean it out about a month ago...

 

[sham]

Ok, so I being the idiot I am didn't read the manual properly before removing the carb from its tight nesting spot, but here are some interesting points which I think I can work off.

I undid the drain screw, but only a couple drops of petrol came out. This to me meant that there wasn't much fuel getting into the float, so I took the carb out. In my head, I was looking for was the "thing" which you're suppose to count how many turns it was to tighten (pilot screw) but I thought it was a jet.

So dismanted the float and found that petrol had been in it, but that it hadn't reached the carb bore. So I went about looking for this "thing". Finally found it scanning the manual and realized it was on the exterior body...

Anyways, below is a diagram from the manual which shows that the pilot screw as an integral part of the air supply / starter system, so my question would be, given that there is evidence of petrol in the float bowl, but not enough to be gushing out when I loosen the drain screw - that there was no evidence of petrol reaching the carb body, is the pilot screw my most obvious culprit for now? And does anyone know how tight it should be / how many turns should I screw it in to? Also I don't actually have a pilot screw plug - is this an issue? Also, seeing as I have no filter material in my airbox, I took it out - should I be reinstalling this as well?



It will take me about an hour just to get the carb back into place to check my theory, so I want to make sure I'm not totally off track before I do it lol.

Thanks.

 

[sham]

Ok so after some suggestions from kz forum, I've found one reason which may contribute to the fail starting. The fuel level in the float is too low - the recommended levels from the manual are 2.5mm ± 1mm below the bowl. Mine started off at 5mm. To fix this I was suppose to adjust the tang, the issue is I seem to have the wrong tools and have been making it worse...

I adjusted the tang twice, moving it towards the valve (wrong) and then away from the valve (right), however, the fuel level was getting lower and lower each time. I have a feeling this is because of pliers, that I must be inadvertently pushing the point of connection between the tang and needle towards the valve as I've been adjusting.

Can anyone suggest how they've been doing this?