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Discussion Starter · #1 · (Edited)
As I mentioned on the title..
How can I lean mid range without changing needle clip position?

Info:
Some months ago I started a thread on fitting and jetting the raptor660 carbs on to my 1990 Yamaha XT600E (4valves) which has "basically" the same engine as grizzly 600.. and I don't want to bring a 1year old thread back from the dead...

After thinking about it alot I figured out raptor is 660ccm.. mine is 600 (595 whatever) which makes jets 11% larger than what I need...in theory that is...

Raptor mains are 140 and 145 due to the 30-70% ratio of the 5th valve so 142.5 average (average because of mine being 4valves).

so for jetting:
Mains 142.5 - 11% = ~125 or 127.5
Pilot: 22.5 - 11% = ~#20

Mods:
-I've got a K&N RU-4710 with an Outwear with this custom "airbox" I made:

(only thing it has over the airbox is the seat and on the sides, the sidepanels)
-Have a bigbore "Devil" downpipes
-Have an opened up WR450 exhaust pipe (removed the internal lid that has 2 small diameter pipes).


BUT a lot of time trying different stuff, and about 6 months of not even riding the bike (one phase of the alternator burned and killed my battery) I'm on a standstill.

I've got a Vito's needles + stock fuel screws from a new rebuild kit...


Before, I had the needles on 4th clip from top, 132.5's, #22.5 and 2 turns out on the FS: the bike hesitated a bit at constant throttle under 1/2 throttle from being way overrich but in wot it pulled awesome!
If I let go of throttle at WOT and go WOT again it would hesitate a bit untill only the mainjet came in the picture...


-On 3rd clip it didn't hesitate quite as much but the hard acceleration faded a bit...


-Tried the stock needles on 3rd clip and no good. Wouldn't go to WOT and had to accelerate slowly for the bike to pickup some speed without hesitating... it made it way lean!


-Right now I've got the Vito's needles with clip on 2nd groove from top, 132.5 (Mikuni) main jets, stock size enrichment jet, #22.5 pilots and 1.5 turns out on the stock fuel screws.


-The hesitation has almost gone away but the hard acceleration is not all there anymore as it was in the 4th clip.


-The bike runs goodish (not as good as I want) but still has a slight rich mid range(and probably low as well), comparing WOT with the needles on 4th groove that is..



SO HERE IS THE QUESTION:


How can I lean out the mid range enough to keep the Vito's needle clips on 4th groove and keep the hesitation before mid throttle and that split second hesitation after letting off WOT and going WOT again? (that was managed to almost fully heal with the needles at 2nd clip)


I would consider going back to stock needles but I guess I would need to increase the mains quite a bit to get that awesome acceleration again no????


Should I get #15 #17.5 #20 pilots to try them out?
Shim the needles? basically changing the clips by half a notch...

Spares I've got:
Mainjets (in pairs) from 127.5 to 145's in 2.5 increments! +vito's single jets that came with the jet kit....
Stock needles
#25 pilots (one pair) from the Vito's jet kit...


Vito's fuel screws: in the garbage...(broke the tips)...


You guys are the big experts on the subject..

I need help :(
Anyone???

P.S.: Sorry for the freaking long post.. Had to mention all the factors...
Vando
 

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As I mentioned on the title..
How can I lean mid range without changing needle clip position?

Info:
Some months ago I started a thread on fitting and jetting the raptor660 carbs on to my 1990 Yamaha XT600E (4valves) which has "basically" the same engine as grizzly 600.. and I don't want to bring a 1year old thread back from the dead...

After thinking about it alot I figured out raptor is 660ccm.. mine is 600 (595 whatever) which makes jets 11% larger than what I need...in theory that is...

Raptor mains are 140 and 145 due to the 30-70% ratio of the 5th valve so 142.5 average (average because of mine being 4valves).

so for jetting:
Mains 142.5 - 11% = ~125 or 127.5
Pilot: 22.5 - 11% = ~#20

Mods:
-I've got a K&N RU-4710 with an Outwear with this custom "airbox" I made:

(only thing it has over the airbox is the seat and on the sides, the sidepanels)
-Have a bigbore "Devil" downpipes
-Have an opened up WR450 exhaust pipe (removed the internal lid that has 2 small diameter pipes).


BUT a lot of time trying different stuff, and about 6 months of not even riding the bike (one phase of the alternator burned and killed my battery) I'm on a standstill.

I've got a Vito's needles + stock fuel screws from a new rebuild kit...


Before, I had the needles on 4th clip from top, 132.5's, #22.5 and 2 turns out on the FS: the bike hesitated a bit at constant throttle under 1/2 throttle from being way overrich but in wot it pulled awesome!
If I let go of throttle at WOT and go WOT again it would hesitate a bit untill only the mainjet came in the picture...


-On 3rd clip it didn't hesitate quite as much but the hard acceleration faded a bit...


-Tried the stock needles on 3rd clip and no good. Wouldn't go to WOT and had to accelerate slowly for the bike to pickup some speed without hesitating... it made it way lean!


-Right now I've got the Vito's needles with clip on 2nd groove from top, 132.5 (Mikuni) main jets, stock size enrichment jet, #22.5 pilots and 1.5 turns out on the stock fuel screws.


-The hesitation has almost gone away but the hard acceleration is not all there anymore as it was in the 4th clip.


-The bike runs goodish (not as good as I want) but still has a slight rich mid range(and probably low as well), comparing WOT with the needles on 4th groove that is..



SO HERE IS THE QUESTION:


How can I lean out the mid range enough to keep the Vito's needle clips on 4th groove and keep the hesitation before mid throttle and that split second hesitation after letting off WOT and going WOT again? (that was managed to almost fully heal with the needles at 2nd clip)


I would consider going back to stock needles but I guess I would need to increase the mains quite a bit to get that awesome acceleration again no????


Should I get #15 #17.5 #20 pilots to try them out?
Shim the needles? basically changing the clips by half a notch...

Spares I've got:
Mainjets (in pairs) from 127.5 to 145's in 2.5 increments! +vito's single jets that came with the jet kit....
Stock needles
#25 pilots (one pair) from the Vito's jet kit...


Vito's fuel screws: in the garbage...(broke the tips)...


You guys are the big experts on the subject..

I need help :(
Anyone???

P.S.: Sorry for the freaking long post.. Had to mention all the factors...
Vando

So you have a bike, not a 660 Raptor, and it is a 600cc engine, and does it have one carb or two,...................
 

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Discussion Starter · #3 · (Edited)
From stock it has 2 carbs... one of those weird twin setups Yamaha YDIS... one is a round slide and the other is a CV.. Was lol...
pic:



I've been running the raptor carbs since before last summer up until September when the alternator gave up finally...


Here is a side picture of the bike and the "Grizzly" engine and the initial design for the air filter:
 

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From stock it has 2 carbs... one of those weird twin setups Yamaha YDIS... one is a round slide and the other is a CV.. Was lol...
pic:


I've been running the raptor carbs since before last summer up until September when the alternator gave up finally...


Here is a side picture of the bike and the "Grizzly" engine and the initial design for the air filter:
No pictures............
 

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Where do the two vent lines that hook up to the carb tops go to, on the raptor they hook to the intake tubes..........
 

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Discussion Starter · #7 ·
They connect to the intake tubes..


Sorry for the bad pics...

It's all good, no air leaks, new intake (engine to carb) boots,
The gray PVC pipe that links to the carb-airfilter have no leaks.. looks kinda funny but it's tight! ;)
 

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Discussion Starter · #8 ·
Another picture:


On this side I have a clean/transparent tube and on the left side of the carb I use the normal right side tube due to the S-curve shape of the tube to avoid hitting the frame...

And they are all tightened with hose clamps!
 

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If you're airbox is open as stated, then the equivalent 660 mains would have been 160/165 NOT 140/145 stockers... 162.5 mean, -11% = 144.5; I think your mains may be too lean.
 

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Discussion Starter · #10 ·
Hi!

QuadM: Think they are too lean? I can try the 145's later today after sleep and see how it works out... it's about a 10% increase over the 132.5's....

How much does the Outwear restrict air flow? Maybe take it off after I try the 145's to see if anything changes?

I thought I was on the rich low/mid range because after changing the Vitos needles from 4th notch to 2nd(leaner) it solved almost all the hesitation on mid-range when on WOT-release throttle-WOT again..


I'ma also take some pictures later today to show the airbox + side covers in more detail as well..

Back in 9 hours ;)
Vando
 

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Discussion Starter · #12 ·
Hey guys!

Well, I haven't done much on the carbs these last few days as the weather sucks right now.. heavy fog, rain...just plain hideous...

I do have been looking around the "jetsrus" and I found they have a link for different needles for the Mikuni..

http://www.jetsrus.com/a_jets_by_carburetor_type/needle_mikuni.html

Does anyone know which needles the Vito's jetkit has according to this webpage? I haven't got a micrometer to measure the needles... :\


Vando :)
 

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Master of the Electron
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Hi!

QuadM: Think they are too lean? I can try the 145's later today after sleep and see how it works out... it's about a 10% increase over the 132.5's....

How much does the Outwear restrict air flow? Maybe take it off after I try the 145's to see if anything changes?

I thought I was on the rich low/mid range because after changing the Vitos needles from 4th notch to 2nd(leaner) it solved almost all the hesitation on mid-range when on WOT-release throttle-WOT again..


I'ma also take some pictures later today to show the airbox + side covers in more detail as well..

Back in 9 hours ;)
Vando

Almost no restriction, in my experience, from Outerwear.

I make my too lean suggestion solely from your assertion that your engine size, and therefore your jets, are 11% less than the 660... yet you reference the STOCK 660 jet size which would NOT be viable for the open airbox - the increased size I referenced would be and, therefore, the 11% reduction should be from the 162.5 mean, not the stock 142.5.
 

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All this jetting you are trying to do comparing to the stock 660r engine is plausible, but my feeling is you cant compare it because you have a different engine with different cam, intake, air box and exhaust.
Another thing I am seeing you are doing is trying main jets and at the same time trying to adjust your midrange by varying the clip in the needle and you still aren't sure if the main is correct. Your first goal is to get the correct main jet, making sure you have sufficient fuel at full throttle and then start adjusting with the needles and pilots.
Once you get the mains roughly right, meaning with in a size or so, the start adjusting your needle and then worry about the pilots...............:)
 

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Discussion Starter · #15 ·
Hey guys!

Thanks for the help!
I think I've sorted it out thanks to you! :)

I've got 145's, stock needles with clips on middle grooves and thin washer on the bottom, #22.5 pilots and right now still 3turns out on the fuel screws and think it's not quite there as sometimes the smooth idle skips... by skipping I mean it sounds like a fart..will try to go with the thick washer on the needle to check if I can gain a little more edge...also will have to go to 2.5turns or even 2 turns on the F.S.s to see if idle gets better...

I wasn't however, able to test the WOT hesitation in 5th gear as I'd have to go over 140km/h and there is just to many crazy people on the road on the weekends..

Will only try those changes I mentioned above AFTER checking if there is still that Wot-let go of throttle-Wot again..

Thanks again so much!
You guys rock!

Vando :)
 

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Just an FYI, when I was WAY too rich at idle (my choke was stuck on), it idled like a Harley - sounded like it would fire twice then miss one, then repeat... In your case, this sounds like your 'skipping'.

Try closing your fuel screws 1/4 to 1/2 turn each (CW).
 

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Discussion Starter · #17 ·
Hi QuadM..

If tomorrow weather is nice I'll have a go at the carbs again and will do that!
Well, the weather was crappy today so I only for fitted and hacked a H4-3 55w bi-xenon 4300K kit with telescopic bulb...

Now I can say I'm able to see at night! :wow:



Vando :D
 

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Hey guys!

Thanks for the help!
I think I've sorted it out thanks to you! :)

I've got 145's, stock needles with clips on middle grooves and thin washer on the bottom, #22.5 pilots and right now still 3turns out on the fuel screws and think it's not quite there as sometimes the smooth idle skips... by skipping I mean it sounds like a fart..will try to go with the thick washer on the needle to check if I can gain a little more edge...also will have to go to 2.5turns or even 2 turns on the F.S.s to see if idle gets better...

I wasn't however, able to test the WOT hesitation in 5th gear as I'd have to go over 140km/h and there is just to many crazy people on the road on the weekends..

Will only try those changes I mentioned above AFTER checking if there is still that Wot-let go of throttle-Wot again..

Thanks again so much!
You guys rock!

Vando :)
You keep talking of adjusting the idle mixture problems with your needles, needles have nothing to do with your idle mixture, the fuel screws and pilot jet do.............
 

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Discussion Starter · #19 ·
Sorry, I must've written it wrong.... I meant going 2.5 turns on the fuel screw to fix the idle problem Plus, I'll try to change the needle clips to give better WOT... two different things... :S

Still, crappy weather over here and couldn't do anything on the bike today :\


Vando
 
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