CBR won't fire.

[dynamite9585]

cranks over and sounds fine, sounds like it REALLY REALLY wants to go. and backfires (big ones)
but just won't kick!!!!!!!!

a bit of google suggests plugs. and that CBR's don't like the cold.
2 part question: does this sounds like a plug problem? (just tried 2 more times after letting it sit for 30 mins same result)

2: anyone in hamilton (pref near claudelands, have a garage, tool kit and experience on these kinds of repairs/servicing that would be willing to give a couple of noobs a hand?

i can find my way around the car engine block ok, but not sure where to start pulling stuff off the bike

[neels]

Has the bike been running recently? If not it could be worth putting some fresh petrol in the thing and draining the carbs.

Are you trying to start it with or without choke? My sons GSXR250 starts best with full choke and no throttle, even if it's not really that cold.

Could be that you've flooded it, try winding it over with no choke and the throttle wide open then go away and have dinner/watch something on telly, then try it again. Worth a try before you get into pulling plugs out etc.

[dynamite9585]

tried flood start procedure already.
fired up yesterday when we went to buy it (push start), fired up this morning a dream, no choke, and about 1 sec on the starter. (charges the batt last night)

we let it idle a bit and went to do our bits and peices, came home to have our first ride and have been bashing our heads agianst the wall for about 2 hours now

[mikemike104]

When I first got my bike I kept having issues with starting it too, turned out it needed no choke so I was always flooding it, I assume you have tried starting it with full then half then no choke just to test it?

[dynamite9585]

have tried every combination of choke/no choke, no throttle/full throttle and all the bits in the middle

[nathan.read]

Sounds like my new bike, started fine a number of times and then would back fire but not start.

The spark plugs were fouled, new plugs and it starts within a second of started (even with a broken choke cable) but it does live in a garage in Northland so its not cold

[=cJ=]

Yup, I had this issue (three are easy, fourth is from hell).

Pull and clean the plugs, if this doesn't fix it, close up the gaps a bit.

[mrchips]

Sounds like my new bike, started fine a number of times and then would back fire but not start.

The spark plugs were fouled, new plugs and it starts within a second of started (even with a broken choke cable) but it does live in a garage in Northland so its not cold

+ 1 fouled plugs.

[dynamite9585]

i'm leaning more on the convinced it's the plugs side of the fence eevery moment, problem is i found out 30 mins after ripco or super crap auto closed.

[imdying]

More plugs are changed prematurely than they need to be. Use the choke, and don't open the throttle even a little. I've seen even shagged ones of these start up with a little encouragement if you follow the rules.

[dynamite9585]

More plugs are changed prematurely than they need to be. Use the choke, and don't open the throttle even a little. I've seen even shagged ones of these start up with a little encouragement if you follow the rules.

tried that, even squirted a little engine start, no dice

[=cJ=]

i'm leaning more on the convinced it's the plugs side of the fence eevery moment, problem is i found out 30 mins after ripco or super crap auto closed.

You should be able to get away with cleaning up the old ones if they're just fouled. And do the gaps properly too :-)

[Icemaestro]

What did the plugs look like? I had that for a bit on mine a while back - the diaphragm on the fuel tap was buggered and the plugs were getting a little fouled (plus was winter and was running lean)..
From memory you can bypass the vacuum fuel pump problem (badly) by removing the vacuum tube from the carb, put a screw in it to block it off. You just need to make sure you turn the fuel tap off every time you turn the engine off.

[scracha]

What did the plugs look like? I had that for a bit on mine a while back - the diaphragm on the fuel tap was buggered and the plugs were getting a little fouled (plus was winter and was running lean)..
From memory you can bypass the vacuum fuel pump problem (badly) by removing the vacuum tube from the carb, put a screw in it to block it off. You just need to make sure you turn the fuel tap off every time you turn the engine off.

Clean the plugs - why bother. If you've went to the hassle of pulling them out then just replace them. Gawd only knows how old they are. Chances are they're fucked and will leave you stranded somewhere you don't want to be. You'll appreciate the better running and the fuel savings will pay for the new plugs anyway.

Backfires mean unburnt fuel so I'd say the fuel pump/filter are OK. Be unlikely to be all 4 plugs so I reckon you're barking up the wrong tree with the spark plug thing. Go back to basics, pull out each plug, earth it and check for a nice fat spark. If it's a pair of plugs then check the corresponding coil. Obviously check for fauly HT leads too.

Drain carbs and put in new fuel. Bump or tow start the fooker (might be battery/starter).

Compression test and/or check valve clearances. If its an early one they're screw and locknut and a piece of piss.

If it's been sat for ages it could just be a combination of all of the above.

[mikemike104]

any luck with it ?