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nc30 not reving past 6000rpm

Posted: Fri Sep 09, 2011 9:04 am
by quinn12
Hi guys

I looked through the forum and saw some related isues to my question, but I have checked the speedo and all, all the manufaults gets hotand looks like they are round the same temp, when my bike running at between 70 and 90 temp the revs will not go past between 8000 and 9000, could it be just the jets that needs to be set properly?

I took of the carb and cleaned it out thoroughly, gave the jets 1.5 turns out and left it like that, the bike starts with choke and idle for a while and then dies, when its running temp and choke is closed, it will idle for round 5 sec and then die, how do I set the idle jet and mid range? It looks like the bike is stock standard but for the exost pipe.

Re: nc30 not reving past 6000rpm

Posted: Fri Sep 09, 2011 10:52 am
by magg
Is the vacuum line to the fuel tap dis-connected or split, engine may be starved of fuel.

Re: nc30 not reving past 6000rpm

Posted: Fri Sep 09, 2011 11:04 am
by Alex_ludd
Hi quinn

First off, take a look at cammo's carb set up guide which you will find at the top of the workshop section or click this link viewtopic.php?f=24&t=14524

this will make sure your carbs are set up properly

2nd gonna need some more info how long has it been doing it, have you carried out any work on it recently,
is it making any strange noises, are you revving it in neutral or while riding and anything else you think may be relevant.

check the fuel tap and vacuum hose are working correctly

probably also worth checking your electrics as well battery reg/rec plugs coils etc

check all the cylinders are firing feel the exhaust pipes to check they all get hot

hope this helps

alex

Re: nc30 not reving past 6000rpm

Posted: Fri Sep 09, 2011 11:14 am
by CMSMJ1
Also - Gauteng is high altitude - it is about 4500feet above sea level is it not? So, you'll need to factor this in for the jetting. You'll need smaller jets as there is simply less air up there!

Re: nc30 not reving past 6000rpm

Posted: Fri Sep 09, 2011 12:16 pm
by Neosophist
quinn12 wrote:Hi guys

I looked through the forum and saw some related isues to my question, but I have checked the speedo and all, all the manufaults gets hotand looks like they are round the same temp, when my bike running at between 70 and 90 temp the revs will not go past between 8000 and 9000, could it be just the jets that needs to be set properly?

I took of the carb and cleaned it out thoroughly, gave the jets 1.5 turns out and left it like that, the bike starts with choke and idle for a while and then dies, when its running temp and choke is closed, it will idle for round 5 sec and then die, how do I set the idle jet and mid range? It looks like the bike is stock standard but for the exost pipe.
You don't turn the JETS out, you screw them in fully.. you turn the pilot screws (outside of the carbs) out 2 turns or 2.5 turns

Re: nc30 not reving past 6000rpm

Posted: Mon Sep 12, 2011 8:41 am
by quinn12
thanks for the advice guys,

I am new to this, so please bear with me. lol

I tried using the carb guide but didint help me much, will try again tonight.

I dont know what the people that had the bike before me did, when I bought it they said it doesnt start cause its has been standing for a year, so i took out the carbs and cleaned all the jets and put then back the way I found them (bike still not starting), I have put in new plugs and a new battery (finaly got it started) but when I rev it in neutral it revs smoothly, but when I take it on the road she didnt want to rev past 8000rpm, yesterday I took off the carbs again and checked all pypes leading to an from the carb, all looks good, put the back and the she starts but didnt want to idle without the choke, I turned the idleing knob till she would idle without the choke but now revs would just climb, I drove around a bit till the temp was at round 80 deg, and tried taking the revs past 800 again, she would splatter at 8000, when I kept the throttle open she would slowly get over 8000 to 10000, but then I got scarred that I will hurt the motor.

so there is the story as to now, will check the pilot screws tonight and give some feedback tomorrow.

thanks again for all the advice so far. really appreciate it

Re: nc30 not reving past 6000rpm

Posted: Mon Sep 12, 2011 1:06 pm
by Andy666
magg wrote:Is the vacuum line to the fuel tap dis-connected or split, engine may be starved of fuel.
This.
Sounds a lot like what mine was doing, check the thin black rubber vacuum hose going from the fuel tap to the cylinders. When hot, if the pipes old it can collapse in and stop fuel from the tank.

Re: nc30 not reving past 6000rpm

Posted: Tue Sep 13, 2011 8:21 am
by quinn12
hi ppl

Sorry but a quick question, I see that non of the pipes on the fuel tank and tap has got clamps on them, could it be that? I took the carbs of last night a turned the pilot screws back in fully and the gave them 2.25 turs out again, but still splatters when trying to get passt the 8000rpm mark.

Re: nc30 not reving past 6000rpm

Posted: Tue Sep 13, 2011 1:25 pm
by quinn12
I will also get som 1mm washers and put them on the needle and drill the vacum holes to 2.5mm, hope fully that will sort out my problems.