Date: 19-03-24  Time: 06:02 am

Author Topic: Re-Jetting the carburettors  (Read 7679 times)

adeejaysdelight

  • WSB Pack Hound
  • *****
  • Posts: 974
  • I love riding my bike!
    • Main bike:
      FZS600 00-01
    • - Tuono RSV, YZF 1000, CBF 125
    • View Profile
    • www.roadrashjeans.com
Re-Jetting the carburettors
« on: 14 February 2014, 10:28:31 am »
Hi Guys,


I was thinking of re-jetting the carburettors on my FZS 600. I have a full Leo Vince exhaust system and K & N filter, so the standard set up is not right. The bike also pops and spits on the overrun, which I love, but it means it is running lean and that can damage the engine, right?


I had a look at these kits - http://www.6sigmajetkit.com/yamaha-fzs-600-fazer-jet-kit.html & http://www.dynojet.co.uk/index.php/vehicle-info?make=YAMAHA&model=FZS600+FAZER&year=2000&Go=Go


Not sure which to go for, if any?


I guess I am just board of the freezing winter nights and need something to do. My internet search history is getting crazy. I spent about 3 hours last night reading about dogs... I don't even own a dog and have no plans on getting one. Although a Burnese Mountain Dog seems like a great pet, if anyone is interested  :rolleyes


Anyway, any of you guys done this job? Is it worthwhile? And which kit would you go for?


Cheers
Not quite sure what to do with my early mid-life crisis. Ideas on a post card to P.O.BOX 150...

noggythenog

  • GP Hero
  • ******
  • Posts: 4,991
    • Main bike:
      Other
    • - TRX Noggyfighter
    • View Profile
Re: Re-Jetting the carburettors
« Reply #1 on: 14 February 2014, 10:40:36 am »
Ha ha ha ha ha!!!!!, that's what night shifts are for..




Im just watching Carl Pilkingtons the moaning of life & then i popped on here for 2 minutes & i can imagine your very message in his accent lol :lol




Anyway...all  the stuff ive read on here says that the fazer runs lean as standard and re jetting isnt required unless you have some serious modifications.....but there's a recent post about changing the jets to suit pod filters and it seems that it's more because not many folk have tried it yet, maybe thise involved will have some success soon.






Plus a good session with a tuner on the dyno could see the bike set up properly without changing jets perhaps.
Easiest way to go fast........don't buy a blue bike

BBROWN1664

  • Administrator
  • GP Hero
  • ******
  • Posts: 13,062
  • Should get out more!
    • Main bike:
      FZS600 00-01
    • - Tracer 900
    • View Profile
    • My website
Re: Re-Jetting the carburettors
« Reply #2 on: 14 February 2014, 10:54:43 am »
The FZS600 doesn't need rejetting. Just get the TPS set up properly and make sure the carbs are balanced properly. It runs a bit rich from the factory.
Another ex-Fazer rider that is a foccer again

Dead Eye

  • GP Hero
  • ******
  • Posts: 3,753
  • What doesn't kill me, will only make me stronger.
    • Main bike:
      FZS 1000 Gen1
    • - FZS600 00-01
    • View Profile
Re: Re-Jetting the carburettors
« Reply #3 on: 14 February 2014, 10:55:16 am »
I'm fairly sure ade the blade re-jetted his 600 due to it stuttering - this is unfortunately documented in the huge 40+ page stuttering thread on the 600 board :P

If my memory serves, he went up two sizes?

darrsi

  • GP Hero
  • ******
  • Posts: 10,633
    • Main bike:
      FZS600 00-01
    • View Profile
Re: Re-Jetting the carburettors
« Reply #4 on: 14 February 2014, 11:12:20 am »
My bike used to pop a lot but balancing the carbs helped it a lot.
I had my carbs cleaned at PDQ years ago and he changed my jet size but it wasn't long before i had the bike back in and he put them back to standard as it just didn't feel right.
More people are born because of alcohol than will ever die from it.

Fuzzy

  • WSB Pack Hound
  • *****
  • Posts: 683
    • Main bike:
      FZS600 00-01
    • View Profile
Re: Re-Jetting the carburettors
« Reply #5 on: 14 February 2014, 11:46:43 am »
Like Darssi, I went to PDQ and when I was there I asked about re-jetting and was told that it is rarely necessary on the FZS600 and that Dynojet took ages to release a kit because of that. So I wouldn't bother.

Back to looking at Bernese Mountain dogs I'm afraid  :lol

Motorbreath

  • Club Racer
  • ****
  • Posts: 440
    • Main bike:
      Other
    • - YZF1000R ThunderAce
    • View Profile
Re: Re-Jetting the carburettors
« Reply #6 on: 14 February 2014, 12:09:21 pm »
Haha you have improved the suspension and now you feel the bike could do with more power. You may end selling the fazer instead the thunderace.  :evil

Seriously speaking my fazer didn't need rejetting having a bmc filter and open exhaust, according to a couple of mechanics it was running great. Also I believe exhaust popping means rich mixture.

My ace doesn't pop so nicely :(
« Last Edit: 14 February 2014, 12:11:10 pm by Motorbreath »

adeejaysdelight

  • WSB Pack Hound
  • *****
  • Posts: 974
  • I love riding my bike!
    • Main bike:
      FZS600 00-01
    • - Tuono RSV, YZF 1000, CBF 125
    • View Profile
    • www.roadrashjeans.com
Re: Re-Jetting the carburettors
« Reply #7 on: 14 February 2014, 12:25:11 pm »
Ok then, off to dynotech ecosse then. I will see how it performs first before I order anything.


Also, the Finnish Spitz looks like a great breed if you like to go running or cycling.
Not quite sure what to do with my early mid-life crisis. Ideas on a post card to P.O.BOX 150...

Fuzzy

  • WSB Pack Hound
  • *****
  • Posts: 683
    • Main bike:
      FZS600 00-01
    • View Profile
Re: Re-Jetting the carburettors
« Reply #8 on: 14 February 2014, 12:27:40 pm »
Problem solved, this is what you need. He's even on a Fazer.

http://i.imgur.com/bL3o4.jpg

BBROWN1664

  • Administrator
  • GP Hero
  • ******
  • Posts: 13,062
  • Should get out more!
    • Main bike:
      FZS600 00-01
    • - Tracer 900
    • View Profile
    • My website
Re: Re-Jetting the carburettors
« Reply #9 on: 14 February 2014, 02:19:56 pm »
:agree

I like that Fuzzy.
Another ex-Fazer rider that is a foccer again

locksmith

  • FOC-U Official Selfish Bastard
    A bit of a cheapskate
    imageJune 09
  • GP Hero
  • ******
  • Posts: 9,947
    • Main bike:
      Other
    • - MT-09 :)
    • View Profile
Re: Re-Jetting the carburettors
« Reply #10 on: 14 February 2014, 03:34:18 pm »
Brilliant, I'd love to take my dog out on the bike, we'd have some good times out together :)

adeejaysdelight

  • WSB Pack Hound
  • *****
  • Posts: 974
  • I love riding my bike!
    • Main bike:
      FZS600 00-01
    • - Tuono RSV, YZF 1000, CBF 125
    • View Profile
    • www.roadrashjeans.com
Re: Re-Jetting the carburettors
« Reply #11 on: 14 February 2014, 05:43:20 pm »
Yes. YES...!!!


Forget re-jetting, I'm getting a dog and were going biking.  :lol
Not quite sure what to do with my early mid-life crisis. Ideas on a post card to P.O.BOX 150...

noggythenog

  • GP Hero
  • ******
  • Posts: 4,991
    • Main bike:
      Other
    • - TRX Noggyfighter
    • View Profile
Re: Re-Jetting the carburettors
« Reply #12 on: 14 February 2014, 06:35:58 pm »
Border terriers all the way! 8)
Easiest way to go fast........don't buy a blue bike

wezdavo

  • Weekend Warrior
  • ***
  • Posts: 243
    • Main bike:
      Other
    • - 954 fireblade
    • View Profile
Re: Re-Jetting the carburettors
« Reply #13 on: 14 February 2014, 07:51:22 pm »
My understanding on the pops on overrun is caused because closing the throttle is putting the carbs into the idle (pilot) circuit which doesn't  supply enough fuel to match the engine speed, a standard exhaust combats this with back pressure which slows down the flow so the pops arnt heard??

I don't think a engine running lean on overrun is anything to worry about because its not under load...

Best way to check if your bike is running lean is to check the plugs..

Punkstig

  • GP Hero
  • ******
  • Posts: 2,191
    • Main bike:
      FZS600 02-03
    • View Profile
Re: Re-Jetting the carburettors
« Reply #14 on: 14 February 2014, 10:24:57 pm »
I have a stubbied scorpion can on mine and the overrun pops are awesome!
Some say...

adeejaysdelight

  • WSB Pack Hound
  • *****
  • Posts: 974
  • I love riding my bike!
    • Main bike:
      FZS600 00-01
    • - Tuono RSV, YZF 1000, CBF 125
    • View Profile
    • www.roadrashjeans.com
Re: Re-Jetting the carburettors
« Reply #15 on: 14 February 2014, 10:56:58 pm »
I agree that overrun pops are the best thing in the world next to no gag reflex, bet they are not the best thing for your bike. Are they?
Not quite sure what to do with my early mid-life crisis. Ideas on a post card to P.O.BOX 150...

spencer_foxwell

  • Weekend Warrior
  • ***
  • Posts: 125
    • Main bike:
      Other
    • - FZ400
    • View Profile
Re: Re-Jetting the carburettors
« Reply #16 on: 15 February 2014, 09:15:17 am »
All popping is, is unburnt fuel exploding in the exhaust pipe. I don't see how that can hurt it?

gassitt

  • Local user
  • GP Hero
  • ******
  • Posts: 1,292
    • Main bike:
      FZS600 98-99
    • - Got lots of others
    • View Profile
Re: Re-Jetting the carburettors
« Reply #17 on: 15 February 2014, 11:45:38 am »
Back in 1998 when I bought my first Fazer I was one of PDQs regular customers .Also at the time they were the main agents for Dynojet in this country and Larry ( the boss) asked if they could have my bike once it was run in to develop Dynojets kits for that model, in return anything they fitted I got to keep gratis. The general conclusion was while improvements were possible they werent massive without serious airbox/intake mods. Memory is a bit hazy but I think they ended up offering Stage 1 and Stage 3 kits , Stage 1 was just a K and N filter for use with standard pipe,  Stage 3 was a filter and slightly different needles to clean up the power curve when using a more open pipe.
I still have the dyno graphs and they do show good improvements in the mid range ( not massive bhp increase but much smoother with less dips in the torque curves) and about 3bhp increase but right at the top end.The mid range improvements were very noticeable.My bike ended up with a K and N and a Remus can with no baffle
At the time Larry said it would be unlikely Dynojet would offer a Stage 7 ( full fat, needles, jets, filter ) kit as the other mods needed to make it work were un-reversible and could leave Dynojet open to litigation for blown motors .If they do offer that now maybe more research has been done so it could be worth doing. At the time the conclusion was Yamaha had done a good job and aftermarket firms could do little but make small gains to clean things up a little

As an example of some one not doing such a good job,PDQ also used my new 1991 750 Zephyr as the development bike for Dynojets kits and sfter initial runs gains could be made.It ended up with a Kerker pipe, full re-jet and serious but reversible mods to airbox that gave 15bhp increase throughout the rev range.I still drool over those graphs and have very fond memories of that bike howling as it came on pipe coming out of Alpine hairpins and yes I still own the bike ( currently undergoing full restoration)

So if youre looking at Rejetting talk to PDQ , theyve been doing it for years and know their stuff.I really should get back down from the frozen north one day and pay a visit to Taplow and chat to the guys ( used to live in Slough and spent many hours at the workshop shooting the shit )

darrsi

  • GP Hero
  • ******
  • Posts: 10,633
    • Main bike:
      FZS600 00-01
    • View Profile
Re: Re-Jetting the carburettors
« Reply #18 on: 15 February 2014, 11:58:54 am »
The main thing that sticks in my mind from PDQ is when Nick constantly tells me you'll never beat the performance of the original downpipes.
More people are born because of alcohol than will ever die from it.