urgent help needed. racing sunday and it wont start

[rigsby]

my mates got a nc29, it has been moded for race use, usual things stripped off generator, lights etc. The loom has also been adapted and unwanted items disguarded.

Our first race with the wirral ended in tears. His bike refused to rev over 7000 rpm, in or out of gear, we checked loom and plugs and stripped carbs about 20 times nothing showed up, his race resulted in a lot of waving to the crowd.
Second race at oulton ended the same. Although it seemed to run OK before scruteneering by the time mornin practice the basterd wouldnt start completely dead, another wasted entry fee.
Anyway with new season looming we changed HT leads and caps new plugs (the colder ones for higher revs) We checked coils etc stripped and cleaned carbs. And result ! it started and was reving upto red line although it was never road tested. Anyhow we are supposed to be off to anglesey tomorrow 20 march. The bike was still running 3 days ago and he tried to start it tonight and nothing! shit. Entrys are paid for aswell. He is getting a spark the battery is charged up (runnin g total loss) but plugs are getting really wet . He has got them out dried em and tried again with same result, it wont fire.

Im sure it is flooding but cant understand why it was running three days ago and now nothing. Can the fuel pump be at fault? giving to much fuel to the carbs as all 4 plugs are getting wet, we are geting sick of stripping the carbs, please help as we only have half a day to get it running.

[sa.racing]

Cooler heat range plugs can sometimes be a pain to start, If there wet chances are they are contaminated (fuel contamination can ruin even brand new spark plugs) so make sure you clean them properly you can heat them up before re-installing them to help aid starting, If you need to replace the plugs (again) you can use CR10EK's out of all the fancy plugs we dyno tested these were the best and only cost about £3 each, While you have the plugs out check the compression as this could also be the problem, Sometimes these bikes just need a bit of persuasion a bit of easy start or even brake cleaner down the intake trumpets and chances are it will fire into life.
Good luck and let us know how you get on
Simon

[rigsby]

cheers simon i am new to this forum and its already paying off.

As it happens i have some cr10ek plugs kicking around from my gsxr slingy, so the higher the number ie 8,9,10 the softer the plug.

i will try these plugs first, i have checked compression and it was very low and did rise when oil was added, but i am unsure the tester was seating right because i tested my nc23 with same tester and got exact same as the troubled nc 29. Mine starts fine though. It was reading around 90 psi on each of the cylinders on both bikes a bit of a coinsidence.

Its now 5.30 am and am about to get the spanners out thought id check forum first.
I will check coils leads and caps again cos its looking like ignition after all, my idea of fuel pump was stupid, grassping at straws you see.
Presume it must be weak spark cos having all 4 plugs wet at same time would suggest weak spark, any other suggestions will help though any other known trouble some electrical parts i should check so can eliminate them.
Looks like we are missing saturdays test day now unless we have imediate success.
Will keep checking forum through out today just incase. And will post the outcome and race results if any!
Cheers guys

[CMSMJ1]

I put a race bike together recently and could not get it to fire on the ER10EH plugs (NC30) I would go back to the standard plugs for starters and try that. Your lack of revving out isues are strange though - Has it ever worked properly?

Do NC29 have a CDI restriction for when the speedo is unplugged? The kind of thing you need an M Max etc for?

Good luck - am sure it can be sorted

[sa.racing]

As it happens i have some cr10ek plugs kicking around from my gsxr slingy, so the higher the number ie 8,9,10 the softer the plug.

That's how it works with NGK plugs but some others are the other way round Champion springs to mind but don't hold me to that, 90psi is way to low but I doubt it would even run with compression that low and if your NC23 runs fine it sounds like your gauge is out, Also make sure your battery is FULLY charged as I noticed my NC29 is very sensitive to battery voltage and even wont spark is the voltage drops bellow a certain number even though it still spins the motor over fast enough to start spent the best part of a day chasing that problem !
As Mark said these bikes have a 112mph speed restriction and removing the clocks will put the CDI into limp home mode and will cut the spark on 2 cylinders @ 5000 RPM so might be worth checking who ever did the loom has bypassed the restrictor but if the bike is reving out to the limiter then it sounds like this has already been done.
Simon

[rigsby]

just an update, i got it running finaly, changed caps leads and found some original cr8 plugs, put these in it sparked great but still wouldnt start(this bike did run fine when in road trim). Stripped carbs again but made sure they were really clean, used an air line took mixture screws out jets everything that could be cleaned was. I noticed one of the choke plungers on number 1 carb wasnt connected to the choke puller, it looks like the recessed nipple had snapped off and was seized in the on position. I managed to release it so at least its in the off position now. I also noticed the inlet rubbers werent tightened up very well, so secured them for a good air tight fit. Anyhow with fingers crossed and the battery off my nc23 it finally backfired into life. Was spluttering for a while running on only 3 cylinders but finally sprung into life. Its revving freely though not sure how it will preform under load ie on track. Its enough of a sign for us to go to test day tomorrow just hope my mate will finally be able to get a few trouble free laps in and hopefully make race day.
Well we will be on our way to anglesey in a couple of hours and with the weather forcast looking good a couple of cold tinnys on the beach will be well deserved, im hoping for a good start to this season, might even get a tan you never know, will post the outcome when were back and hope for better than 12th i had last season, some of the top guys have 80bhp+ zxr 's iv got no bloody chance.

If anyone wants to catch some action in the sun it is the first round of the wirral 100 season at anglesey circuit on sunday racing starts at 11 am and spectators pay a tenner i think, the views are great by the way.
Cheers for all tech help
rigs

[CMSMJ1]

Nice one Rigs,

get the bike up and down the street - you will be buggered if it plays up again when you get there!!

Good luck with your racing..I will be doing a W100 race sometime this year so I will come say howdy...and you can beat me on my DIY NC30..lol