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COP_B8
6th June 2006, 13:39
Just finished cleaning my bike, taking all the panels off, polishing the frame etc.... including taking the tank off. when I put it back together it now wont start, it will turn over fine but wont spring to life, however after 10 seconds plus on the starter motor it will make a huge backfire, any ideas where to start???

Karma
6th June 2006, 13:42
No idea, but I'd suggest that if it's making a huge backfire then probably a good idea to stop doing whatever you're doing at the moment and wait for some advice.

GR81
6th June 2006, 13:42
key is on, kill switch off, bike in neutral?
(start simple) lol

Sniper
6th June 2006, 13:44
There will be water around the leads or you have moved the leads and have put them back incorrectly?

Ixion
6th June 2006, 13:45
In the course of all that, did you maybe remove, and put back again the spark plug caps (ie pull them off the spark plugs) ?

Finn
6th June 2006, 13:51
Have you checked your tyre pressure?

COP_B8
6th June 2006, 13:52
Spark Plug leads werent touched.
No water, spent the night inside whilst i was cleaning it.
Yup keys in there........

Its got me stumped, and I cant think where to start.

COP_B8
6th June 2006, 13:53
Have you checked your tyre pressure?

That was my first thought.........along with making sure the WOF was current....

Str8 Jacket
6th June 2006, 13:55
Well Cam seeing as she wont start you wont be able to sell her... May as well just drop it round to my place and i'll have her as I doubt anyone else will! :blah:

COP_B8
6th June 2006, 13:59
Well Cam seeing as she wont start you wont be able to sell her... May as well just drop it round to my place and i'll have her as I doubt anyone else will! :blah:

Thats why I was cleaning it.....oh well, am waiting to see weither bank will give me money to buy new bike without selling this one, then ive got one spare.

sAsLEX
6th June 2006, 14:00
Maybe try applying some dirt and muck to the fairings! Your bike obviously dont like being clean!

Str8 Jacket
6th June 2006, 14:01
Thats why I was cleaning it.....oh well, am waiting to see weither bank will give me money to buy new bike without selling this one, then ive got one spare.

Im sure you'll get it sorted... Good luck with the new bike, what you gonna get?

COP_B8
6th June 2006, 14:07
Yeah I need it i think, new bike is going to be black, with a bigger engine than my mini and very loud.......no more clues, hopefully see yah tomorrow night though if its going!

poorbastard
6th June 2006, 14:08
Did you take the leads out? If you did you may have put them back incorrectly, I know that happened to my bike when I did that.

poorbastard
6th June 2006, 14:10
Sorry didn't read your other post saying you didn't touch the sparkplugs.

No idea then.....Good luck with it anyway

Str8 Jacket
6th June 2006, 14:12
Yeah I need it i think, new bike is going to be black, with a bigger engine than my mini and very loud.......no more clues, hopefully see yah tomorrow night though if its going!
owwww be like that then!

Rides seem to still be going but my headlights suck more than a mosquito and I cant even see 2 metres up the road so sadly I wont be there. :bye:

COP_B8
6th June 2006, 14:14
Haha, fair enough, Im meant to go and get a new front tyre and brake pads for it tomorrow, but dependant on if i can get it going.

Sniper
6th June 2006, 14:17
Check your leads anyway cause they may have been knocked. You holding your tongue the right way?

NC
6th June 2006, 14:18
Have you got your air feed from the tank in?

COP_B8
6th June 2006, 14:20
Have you got your air feed from the tank in?

There appears not to be an air feed from the tank, there is only the tap, and the pipe exiting the bottom into the drain hose.

GR81
6th June 2006, 14:21
Have you checked your tyre pressure?

have you tried reseting your router?

booyah!!!!! ::nya:

skelstar
6th June 2006, 14:46
Do you think your new bike will have the petrol stored in a tank? ;)

Advice: dont buy the new bike until you sell your old one. You loose all motivation to sell the old one. I should know :).

COP_B8
6th June 2006, 15:03
Yes it will be in the tank, its a jappa.

Motig
6th June 2006, 16:52
Is it getting the gas to all 4 cylinders? You haven't accidentally knocked something out of place with all that vigorous polishing or when putting the tank back on? Spark?

Macktheknife
6th June 2006, 17:14
Start simple, check fuel to all cylinders and then spark to all. this will often sort it out or lead you to the problem. After that check timing and lead conections. Let me know if you still dont get a winner.

COP_B8
6th June 2006, 23:39
How would I check fuel to every cylinder, spark is a bit more trickier, the leads are located out of reach, i have jiggled them to make sure they are on, spent the afternoon CRC'ing and cleaning everything and making sure that all electrical connections were on, still not going though.

One thought was the fuel pump but there is plenty of fuel in the line after it so it must be doing its thing.

wendigo
7th June 2006, 06:18
My guess is that by this stage your problem will be a flat battery. The batteries on those 400's never had much grunt. I found with my NC 23, if it didn't start in the first couple of seconds on the starter, it wouldn't start at all (i.e. using the starter for 10 seconds at a time would only drain the battery super fast). Also found that depending on the age of the battery, the battery didn't have enough power to spin the engine up and provide sparks at the same time. The engine would catch just after releasing the starter switch.

It also sounds like you've well and truely flooded the engine. My suggestion would be to try bump starting it with all the lights etc. turned off. (And charge up the battery if you can)

Note: Checking for fuel - look at the bottom of each carb & you'll see a nipple with a bleed screw. Stick a bit of hosing over the nipple (to stop petrol pissing everywhere) & open bleed screw. If petrol comes out, you're probably getting fuel to that cylinder. Repeat for each carb. With the bleed screw still open on one of the carbs, make sure the fuel pump is still working & fuel is getting delivered to the carbs, by turning on the ignition. Should hear the fuel pump clicking away & more fuel shoukd get pumped out.

My 2c.

COP_B8
7th June 2006, 12:15
My guess is that by this stage your problem will be a flat battery. The batteries on those 400's never had much grunt. I found with my NC 23, if it didn't start in the first couple of seconds on the starter, it wouldn't start at all (i.e. using the starter for 10 seconds at a time would only drain the battery super fast). Also found that depending on the age of the battery, the battery didn't have enough power to spin the engine up and provide sparks at the same time. The engine would catch just after releasing the starter switch.

It also sounds like you've well and truely flooded the engine. My suggestion would be to try bump starting it with all the lights etc. turned off. (And charge up the battery if you can)

Note: Checking for fuel - look at the bottom of each carb & you'll see a nipple with a bleed screw. Stick a bit of hosing over the nipple (to stop petrol pissing everywhere) & open bleed screw. If petrol comes out, you're probably getting fuel to that cylinder. Repeat for each carb. With the bleed screw still open on one of the carbs, make sure the fuel pump is still working & fuel is getting delivered to the carbs, by turning on the ignition. Should hear the fuel pump clicking away & more fuel shoukd get pumped out.

My 2c.

Yes there is fuel in every cylinder and spark in all of them.

Sniper
7th June 2006, 12:23
Coil, leads and check the CDI

Korea
7th June 2006, 13:09
Have you tried cursing loudly? Threatened it? Kicked the tyres? Have you considered torturing it until it gives iin?
If all else fails, try making an offering to the Gods of motorcycling...

Sorry, no idea mate... :shutup:

Cibby
7th June 2006, 14:20
being an expert...

it looks like you have a fuel feed problem considering that you had your tank off.

Does your tank have a lot of shit in it? maybe you have clogged up the gravity fuel feed? Postie had a CBR and his fuel tap broke completely..

i dont want to be patronizing here but you sure you plugged in the fuel pipe correctly? Turned the fuel tap on???? Does it have a fuel pump?? unlikely that it doesnt.. but still maybe..

Could also be an electrical problem, check the wires where the kill switch is..some older bikes will still turn over if that is off.

Hmm that is about all i can think of at this stage..


oh wait i thought of another thing

Check the fuses as well and maybe the battery!!!! they can blow and maybe stop it from firing, unlikely but still.. who knows with thes bikes.

agree with that guy up there who says bump start it!

Sniper
7th June 2006, 14:24
Im tending to disagree with the fuel feed problem. He is saying that there is a big backfire every 10 seconds. There is fuel getting there, its just igniting sporadically.

Cibby
7th June 2006, 14:41
Im tending to disagree with the fuel feed problem. He is saying that there is a big backfire every 10 seconds. There is fuel getting there, its just igniting sporadically.


potentially not enough fuel or intermmitent fuel actually getting into the engine maybe???

Sniper
7th June 2006, 14:47
Thats true.......

wendigo
7th June 2006, 20:12
Any joy?

Forgot to mention to work the throttle as the engine spins over. Find that helps, as it varys the fuel/air ratio & at some stage it will pass through the range optimum for starting. Do that with pretty much every engine I start, even me TL, which you wouldn't expect to have to do coz its fuel injected.

Failing all the advice in the thread not working, get your hands on your mum's car's battery, hook the fucker up and just go nuts...

A word of warning: - in general you shouldn't use the starter for long periods of time at any one go (all the manuals I've come across mention periods of 3-4 seconds as being the max). The reason being there's a serious amount of current flowing through the starter motor when it's going & it will get bloody hot & eventually of course, burn out.


Good luck with it.

COP_B8
8th June 2006, 19:13
I give up,

tryed bump starting (and then towing it back up the hill behind the 4wd) jump starting, definately enough fuel coming through the pump (over the 700cc per min minimum????

Motomart are now looking at it for me, decided the experts can look into it, top service too, they even came and picked it up.

Cam

Speedy
8th June 2006, 19:29
i have just brought a CBR250RR an it does this on ocasion and wen i first brought it , take out all ur fuses an clean them change them around etc and then try 2 start it this wrked 4 me , its can be moisture and or dirt etc pissing off electrics............... i think ............try it ne way

ben444
10th June 2006, 10:57
At a guess... you prob had it running at idle before you cleaned it???
Fouled the plugs, and/or old fuel....

Drain the carbs, and take out the spark plugs and clean/replace em...

Should start ok..

A bit late now that it's in the shop... sorry...

COP_B8
18th June 2006, 17:58
Got it back from the shop:

4 new Plugs, they were fuct apparently
Was missing the rubber seal around one of the inlet manifolds???
Was running way to rich

Runs a hell of a lot better now.

Str8 Jacket
18th June 2006, 18:00
Is itn still for sale? My workmates interested in it...

COP_B8
18th June 2006, 18:17
dunno right at the moment, refer to post regarding small mishap, am getting new brake lever and paint touched up tomorrow.

race_demon
5th July 2006, 13:11
check you havent caught a lead when yuo ptut he tank on sorry i cant help much

failing that ask the 16 year old apprentice mechanic HE KNOWS EVERYTHING!!!