That boggy deep throated sound.

viffer4 · Post by **viffer4** » Wed Jun 04, 2008 3:59 pm

My NC30 will sometimes lose power, around and below 6000 rpm, when it does this she sounds deap throated and boggy. Can anyone suggest anything for this? a couple of times i've wondered if its having the lights on that does it.., so rectifier problem? and a couple of times it seems that when the fuel is running low it is doing it. It also doesnt love revving up to the red line, i dont like thrashing it to hard, but after 13500rpm it feels weaker than i imagine it should.

Also, just a question, i understand the theory of the vaccume tube and diaphram in the fuel switch, however my bike has two possible attachments for the vaccume tube. since the bike runs i spose i've got the right one, but what is this 2nd attachment for?

Many thanks,
John

fastdruid · Post by **fastdruid** » Wed Jun 04, 2008 4:06 pm

viffer4 wrote: Also, just a question, i understand the theory of the vaccume tube and diaphram in the fuel switch, however my bike has two possible attachments for the vaccume tube. since the bike runs i spose i've got the right one, but what is this 2nd attachment for?

It's to let air in to the other side of the diaphram so that the vacuum tap part works under all pressures, it can work kind of in reverse in that if you put positive pressure into it the fuel tap will flow, this can be handy sometimes when working on the bike.

Druid

Post by **royster81** » Wed Jun 04, 2008 4:26 pm

viffer4 wrote:i dont like thrashing it to hard, but after 13500rpm it feels weaker than i imagine it should.John

i might be wrong here but i was lead to believe peak power came in at 10500/12500 something like that and after that all you did was make noise ...which would probably be the reason for it not "pulling" strongly to the limiter

1990nc30 · Post by **1990nc30** » Wed Jun 04, 2008 4:40 pm

royster81 wrote:
viffer4 wrote:i dont like thrashing it to hard, but after 13500rpm it feels weaker than i imagine it should.John
i might be wrong here but i was lead to believe peak power came in at 10500/12500 something like that and after that all you did was make noise ...which would probably be the reason for it not "pulling" strongly to the limiter

That's exactly what my bike feels like, pulls well to about 12k, then after that, like you say royster it just makes noise to make up the rest of the limiter lol! i just don't bother taking it all the way up, there doesn't seem to be a point in doing so other than filling up quicker.

Post by **monkeywithaplan** » Wed Jun 04, 2008 11:25 pm

agreed with all said above, however if you are concerned with its running, and fueling being suspect by your 6k bogging, clean your carbs out and check condition of air filter/plugs etc, check your jet sizes, let us know what they are plus any engine performance mods in case that may be out.

Post by **Cammo** » Wed Jun 04, 2008 11:44 pm

Hmm, every nc30 I've had (standard to pretty modified) has loved living near the limiter, and pulled well all the way to redline.

Maybe it's the air down under.

Post by **CMSMJ1** » Thu Jun 05, 2008 11:17 am

Stickshift wrote:Hmm, every nc30 I've had (standard to pretty modified) has loved living near the limiter, and pulled well all the way to redline.

Maybe it's the air down under.

I'm with you Cam - mine pulls nicely and into the red line...

viffer4 · Post by **viffer4** » Thu Jun 05, 2008 4:47 pm

ah right that makes sence on the vacuume tube.
riight il check the plugs, im a little worried about tackling the carbs myself.. iv done motorcross bikes and that kind of thing but never anything to the tuned 4 carb scale of the nc30. If i try and then mess things up, i dont spose its gona be anymore expencive than getting the unmessed up carbs cleaned n balenced?
nothing 2 lose sort of thing. thanks for your help so far folks. You wouldnt say its likly to be a serious problem, piston rings etc, from what i've said? I have no reason to suspect anything to bad..
cheers

russ tyson · Post by **russ tyson** » Tue Jun 10, 2008 2:10 am

hi its not the rings unless its smoking alot and hard to start, Have to agree my bike will pull all the way to the limiter but its peak power is not on the limiter... have a look at the dyno graphs for these 400s their peak power is not at the limiter or near it. this I think is what ducati used last year to get the gp7 to go faster down the straight more revs/more speed goes past the peak power but carries on reving at lower power to gain maybe 5mph extra at say 19000rpm but peak power might be at 17800rpm. Russ

nc30boiii · Post by **nc30boiii** » Fri Jun 13, 2008 12:47 am

i cant really help but id guess if ur exhaust is giving a deep throated sound maybe u shud ease off and stop gaggin it, although gagging can be fun.

i saw this program the other night about a man who made love to his his cars, hed never had a relationship with a woman, he just liked to rub himself up and against and into his car. even to the point he would lube up his exhaust and eye up other car exhaust in car parks.he was definetely at one with his motors, hahaha

That boggy deep throated sound.

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