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New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 6:09 am
by silentRVF
Hey guys,

I've got a full tyga exhaust with carbon can on order so just wondering if I'll need to rejet. I've currently got stock headers with a Stainless Laser pipe and I'm not sure what size jets are on the bike, but I'll replace them anyways.

The bike will only be used on the road (may go for a track day or 2 in the future but for now it's only street riding). Not sure if this makes any difference but I'm more concerned with getting more fuel efficiency out of the bike than more power (yeah yeah i know, i shouldn't have bought a nice exhaust if i wanted this..) but then again if I keep smaller jets then the bike will run lean and damage the engine so maybe this isn't achievable if I am to go for the Tyga system...

I saw the NC30 jetting guide by Cammo (awesome guide mate!).. I know the NC35 jet sizes are different (108 as standard on RVF), but is everything else the same? What size jets should I put on the bike? I've seen alot of people suggesting 110 for the front carbs and 112 for the rear, does this sound about right? (Why put different sized jets on the front and rear?)

Also, where can I get the jets and the gaskets for the carby? Should I replace the carby screws as well? I know on my CBR250RR I ended up destroying the screws trying to take them off because they were old and worn out..

Also, I haven't yet looked at my air filter but I'd like to replace it with a K&N or Hiflo. There is an eBay listing for a K&N air filter for the NC35 (HA1202) but on the K&n website it says that filter is for the Aprilia RS, and the K&N site doesn't list a filter for the NC35. The picture on the eBay listing also looks different to the one on the hiflo website of the air filter listed for the RVF400..

http://cgi.ebay.co.uk/K-N-KN-Air-Filter ... 259wt_1137

http://www.hiflofiltro.com/17.0.html?&L=0&sel_uid=163

Thanks alot 8-)
PS: Is there a way to get more power down low? The bike seems a little low on power down low, and then you get smacked with all the power up above 8k RPM (which you don't need on the road).. I know I can change the gearing but my chain and sprockets still have plenty of life in them so I won't be doing this for a while..

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 7:52 am
by Drunkn Munky
In short nc30's run different jets front and rear as I belive the rear carbs run slightly hotter, this isn't the case with 35 carbs although your right I have seen people run different jets front and rear on the 35.

Your gunna need 110 jets, standard filter, hrc slide springs and an extra 0.5mm washer under the needles. Rick over sells everything you need Inc stainless bolts to replace the chew'd up ones.

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 8:16 am
by silentRVF
Drunkn Munky wrote:In short nc30's run different jets front and rear as I belive the rear carbs run slightly hotter, this isn't the case with 35 carbs although your right I have seen people run different jets front and rear on the 35.

Your gunna need 110 jets, standard filter, hrc slide springs and an extra 0.5mm washer under the needles. Rick over sells everything you need Inc stainless bolts to replace the chew'd up ones.
Why standard filter?
What are hrc slide springs?
And what does the extra washer do?

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 9:02 am
by CMSMJ1
Standard filter is the best..simple as that.
Do you know how a carburettor works?

The slide springs control the slide as it opens - HRC springs are not as stiff as the normal springs, allowing faster response to WOT.

Adding a washer raises the needle....this makes the midrange slightly richer.

Have a read up on carbs dude - it will all make sense ;)

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 9:13 am
by silentRVF
CMSMJ1 wrote:Standard filter is the best..simple as that.
Do you know how a carburettor works?

The slide springs control the slide as it opens - HRC springs are not as stiff as the normal springs, allowing faster response to WOT.

Adding a washer raises the needle....this makes the midrange slightly richer.

Have a read up on carbs dude - it will all make sense ;)
No I dont know much about how a carby works but will read up tonight.

What's a slide spring worth, and is that the thing that goes behind the needle? Also, what is WOT?

I don't quite understand what the needle being raised does but I'm sure I will once I read up a bit more on carburettors.

Will all of these mods make my bike use more petrol?...

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 9:43 am
by CMSMJ1
Ref petrol - Yes, of course. You are improving the air into the system and so you need to add more fuel too...

WOT = Wide Open Throttle.

The mods you are looking to do are not for fuel saving street runs..they are for making the bike go faster and that takes fuel..

Carbs are simple when you get your head around them.

HRC springs are variable in price, if you can get them at all -Am sure Rick Oliver wil have some or can source some for you.

It is a slippery slope this moto fettling...oh yes! 8-)

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 11:51 am
by J.B.
The carbs on the RVF are fairly simple to work on but there's still a lot of things to be aware of. Before re-jetting I suggest you check the valve clearances and adjust if necessary and as you have to take the carbs off to do this anyway you might as well take care of it at the same time. Definitely buy one of those magnetic probe thingys for picking up small bits of metal first. How do I know this? :oops:

I'm sure this has been posted before but there's an excellent write-up on CV carb tuning to be found here:

http://www.factorypro.com/tech_tuning_p ... gines.html

For what it's worth the main jet sizes did not go up much when I fitted my TYGA full system but every bike is slightly different and climatic conditions play a big factor.

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 2:42 pm
by silentRVF
CMSMJ1 wrote: The mods you are looking to do are not for fuel saving street runs..they are for making the bike go faster and that takes fuel..
Thanks for the comments and advice everyone. Well I'm not really wanting to make the bike go faster, just hoping to gain a bit more bottom end power without sacrificing too much fuel efficiency (which already isnt the greatest).. Maybe I should forget about raising the needle but get the HRC springs to make it more responsive (does this only affect WOT?) and increase the jet size so that the bike doesn't run too lean/rich? Should I go for 110/110 or 110/112 jets?

Cheers
PS: How many km's/litres do you guys get once you hit reserve? The other day I hit reserve and I had only used 12.2L.. and if I remember correctly the tank is 15L so I still had 2.8L...

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 5:12 pm
by Neosophist
Sounds about right.. 2 litres or there abouts for reserve.

14 litres standard for nc24.. slightly less for nc24 i believe..

Re: New Tyga System = Rejetting? Which Air Filter?

Posted: Mon Aug 23, 2010 11:49 pm
by Cammo
jonno92 wrote: Well I'm not really wanting to make the bike go faster, just hoping to gain a bit more bottom end power without sacrificing too much fuel efficiency (which already isnt the greatest)
Just get some bigger main jets and forget springs and raising needles then.

112's all round will be fine.

You can mail order them from http://www.showandgo.com.au/ you'll need 4 x part # 99101-393-1120