Carburetor Jet Tuning - Updates on 1st Post

[TLRam1]

A bike with a K&N and pipes benefits from a 3rd shim, is that correct? If that is the case it should help on all 3rd generation bikes with the same set-up, yes?

If you have made carb adjustments, jetting changes, tuning changes, etc. let us know. What has been your experience? Pilot jets are too small with the 3+ turns out.

Tried different needle jets? Are different needle jets available? Have you taken the main jet higher than a 105, what's your take?

This thread will help others form some opinions on what direction to go. Any input you have will help us all out, so speak your minds, opinions and experiences.


All Updates will be posted to this first page so you will not have to read through the entire thread.


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This is where we are at currently.

From my readings and input from Magna owners, a stock Magna would benefit from the DD Kit. For sure you need to add a Shim and turn Pilot screws out to 2 3/4 turns.

Pilot Jets (#40) for a stock Magna work well, once you do a couple of modifications a change to #42 Pilot Jets would be of benefit. Personal choice, depends on how much you want to spend and how finicky you are.

Greg's beliefs are, Cobra exhaust does not flow as much air as V & H's and my findings are parallel with this. This is subject to change with more Cobra exhaust testing.

I believe most of these are around 500 ft above sea level. High altitude you will have to be on the leaner side.

So far it is coming down to this.
______________________________________________________________________________

Stock Filter

Stock Exhaust

Shims – 1 (additional)

Pilots screws 2 ¾ Turns out.


I have read in several places this statement, I have nothing to back this up but thought I should include the info----- The DD jet+shim kit is designed for a bone stock Magna including the exhaust. In fact, it is the factory stock setup for Non-USA Magnas.

Option,
               #105 Mains

__________________________________________________________________________


Lance – (L J BAD MAG)

K & N air filter

Exhaust Mod

Shims – 1 additional

Mains - 105

Pilots screws 2 ¾ Turns out

Option,
              #42 Pilot Jets
              #108 Mains

Lance - Right now it runs extremely good, no flat spots in the rpm range at all.  I think the 108 jets will make it pull harder on the top end though.. MPG 48.


_____________________________________________________________________________


Greg (Greg Cothern)

K & N air filter

Exhaust Mod.

Shims – 1 additional

Pilots screws 2 ¾ Turns out

Option,
              #42 Pilot Jets
              #105 Mains

Greg - My son's bike is setup like this and it is almost perfect.

I have read in several places this statement, I have nothing to back this up but thought I should include the info----- The DD jet+shim kit is designed for a bone stock Magna including the exhaust. In fact, it is the factory stock setup for Non-USA Magnas.


_____________________________________________________________________________


Greg (Greg Cothern)

Project 96

Stock air filter

SuperTrapps – All diffusers in.

Dyna Jet Kit - clip in 3rd position from bottom

Shims – 1

Pilots – 45 were on hand (prefer 42's)

Pilots screws – 2 1/2

Options,

42 pilots

Will install a  K&N filter

The SuperTrapps have all the provided discs (I will have to count again I think it is 9 discs per side but maybe only 7) installed. ??

Greg - Now it has low moderate decel pop, but midrange is much improved.  So the plan now is to continue to ride it at these adjustments and wait for the K&N to arrive.  See where it sits after the K&N and go from there.

_____________________________________________________________________________


Lawrence (lragan)

K & N air filter

Cobra Slash Cut Exhaust

DD kit which includes

Shims – 1 (additional)

Mains - #105

Pilot screws 3 Turns out

Lawrence - Starting improved, solved the mid-range issue.  Popping on deceleration disappeared mileage dropped from 50 to 45 MPG.

Option,

Additional shim may be of benefit but untested.

Not tested, IMO, I think you could comfortably change the Mains to #108.

Probably should change to the #42 Pilot Jets


______________________________________________________________________________


Kelley Cothern (KTC)

K & N air filter

Cobra Slash cut

Shims - 1 (additional)

105 - Mains

40 - Pilots

Pilot screws – 3 1/4 turns out


Kelly - Pulled plugs and they are mostly white, pipes are clean no black soot. I think it will benefit from .42 pilot jets.

Greg's - His plugs looked a tad on the lean side, not bad though.  The temps immediately after the change were a bit on the cooler side thus increasing the lean condition a bit with the cooler dense air. However, I do believe the 42's will be a good addition.


_____________________________________________________________________


Allen (roboto65)

K & N air filter

Jardine Megaphones exhaust

Shims - 1 (additional)

110 - Mains

45 - Pilots

Pilot screws - 2 3/4 turns out


With what I have done it is ALOT better almost pulls the front end up and it goes all the way to REDLINE, does it need more tweaking, yeah probably, but it is close for sure !!!!!!

Note: possible go to 42 pilot jets and lean the idle jets a 1/4 turn more.

_______________________________________________________________________________


Matt (Magnatic)

K & N

V & H exhaust

Shims - 2 (additional)

Pilot - #42

Mains - #110

Pilot Screw - 2 3/4 turns out

Option,
           #45 Pilots
           #112 Mains

Bike runs strong with seamless powerband up to redline. Issue is some popping on decel so I will go out another 1/4 to 1/2 turn on the Pilot screw. May try112 Mains & 45 Pilots.

______________________________________________________________________


Lance – (L J BAD MAG)

K & N air filter

Exhaust - Vance & Hines

Shims – 1 additional

Pilots - 42

Mains - 110

Pilots screws 3 1/8 Turns out


Lance - The bike pulls very hard all the way to red-line, no dead spots, spot on. I also think the 110 mains helped with the total carburetion as well.

_______________________________________________________________________________


Chad (chadschloss78) (I think this needs updating)

K & N air filter

V & H exhaust

Shims – 2 (additional)

Mains – #110 or #112

Pilots - #45

Pilot screws 2 ¾ turns out

Chad - Torquey, super punchy midrange and unstoppable top end.

____________________________________________________________________________


JETS:

112 Main:
PN: 99101-GHB-1120

110 Main:
PN: 99101-GHB-1110

108 Main
PN: 99101-GHB-1080

105 Main
PN: 99101-GHB-1050

45 Slow Jet:
PN: 99103-MT2-0450

42 Slow Jet:
PN: 99103-MT2-0420

This list will probably need to be tweaked as people test and try these settings but should be better than before.   

These settings are in MOOT Member bikes and actually working so they do have history behind them but might need tweaking as we become more experienced with various setups.

[L J VFR]

Terry, my 01 is all stock exhaust with just the k and n air filter. I talked with greg after adding 1 extra shim for a total of 2 about having a stumble still at around 4000 rpm's. He thought it was still lean at midrange so  i added another shim for a total of 3. I also turned the pilot screw's out to 2-7/8 turn.  This helped my bike quite a bit, hardly any drop  or stumble now at all.  Lance

[Greg Cothern]

I believe the 105 jet is good for this setup when fully on the main jet metering system.  However its the low to mid range transition that suffers from enemic fuel flow, but this is seen mostly with V&H and K&N equipped Magna's.  I would suggest no K&N with these particular mufflers.

OR I shudder to suggest the Dyna-jet kit, as I hate to alter stock parts that Dyna-jet wants, but they do come with a different needle setup that has an "E-Clip" adjustable height as well as the taper being different. 

Dave Dodge's setup works great in that is is less than half the cost of the Dyna-jet, and does not require altering of parts.  However with Dave's setup it has been my experience that you need a total of 3 shims with the K&N and V&H setups.  Remember this shim only raises the needle .020", so with the 3rd shim you are putting it .040" above stock, so its not a huge jump, my guess is that most with this setup would benefit from a .050" raise.

Another thing folks with this setup can do it make sure your airbox, is as much as possible, sealed to keep the incoming airflow correct.

Wish I had a Dyno and a exhuast sniffer to be able to test exactly what will work for the low to mid range just right. 

[TLRam1]

Lance

K & N

Stock exhaust

2 shims- additional

Pilots screws out 2 3/4 turns

This helped my bike quite a bit, hardly any drop or stumble now at all.


Thanks Lance for your input.
____________________________________________________________________

Gregs thoughts,

K & N

Vance & Hines pipes

Shims - 1-2 additional  for a .040"-.060" total raise. Gregs possible ideal raise is .050".

Pilots out 3 ¼ turns


From what I have read and experienced I lean to Greg and Lances experience and thoughts. 


I believe most prefer not to modify as Greg states with the Cobra Jet kit.

My question though, does the Cobra Jet kit correct all issues, will more shims do as well of a job as the Cobra kit (or be pretty close), can you buy a different Needle Jet w/o mods to the carbs?

[Greg Cothern]

I didnt say 4 or 5 shims    2 to 3 max...  As each shim DRP sends is .020" thickness, so 2 additional shims will get you .040" raise on the needle thus richening the midrange some.

[TLRam1]

I didnt say 4 or 5 shims    2 to 3 max...  As each shim DRP sends is .020" thickness, so 2 additional shims will get you .040" raise on the needle thus richening the midrange some.

So sometimes I don't read so good. I thought each washer was .020 but the .050 threw me.

Fixed on the previous post.

[roboto65]

I have entertained the thought of trying different pilot jets and see if that makes any difference but have not done it yet !!!!!!!!!

[TLRam1]

There appears to be 2 different Needle Jet part numbers for this part and the Mains jump to #110 from the stock #102.

Anyone know the difference between the Needle Jets or how to read the difference by the last 3 digits? 


NEEDLE SET, JET
16012-MZ5-600  ------Edit - Cal Model.

NEEDLE SET, JET
16012-MZ5-670

JET, MAIN (#102)
99101-GHB-1020


I did locate this bit of information but it didn't help much plus it may have changed some from the vintage days.


http://www.kaila.net/tl125/tl125partcode.html

Honda Gurus come out of the woodwork........If these other Needle Jets are different, slimmer sooner, and with #110 Mains, well I don't know unless someone here has tried this.

Greg or Allen, do you know of anyone who has tried these?

And I agree, Greg Should get a sniffer! 

[roboto65]

Nope but one of these days I will get around to trying different pilot jet sizes which there are a few.. Also Honda has changes part numbers quite alot so they are probably the same thing but have not ordered either one so just a guess there could be the California models and the other 49 states and the sniffer has been on the tool list for a while LOL

[Greg Cothern]

105's are a good match for the Magna on mains.  The one you list that say mains, well the last 4# show the jet size, ie 1100 is a 110 jet size as it state hehehehe.
The others look like slow speed jet #'s to me, not that I know them by heart.  I would have to refer to a chart or such to help figure this out further.  But I would think if there were/is another slow speed jet that would simply swap out for, then the next size up would be the ticket I think. 
I guess I need to give Dave Dodge a call and chat with him some more hehehehe.

[TLRam1]

I see that now about the Jet numbers, just took someone smarter than me to point that out. 

I forgot about the possibility of the CA. models. Honda listed only one Slow Jet, a #40, but still moving up one would probably be okay. Than again, taking the stock Slow Jet to the max 3 turns might just be enough.

Lance having to add 2 shims with a stock air filter and V & H pipes leads me to believe we need more if we are running a K & N air filter also. Lance may be a bit overkill at certain throttle positions but I don't know unless one of us rides it for comparisons sake.

The consensuses is so far, the stock Magna is lean and would benefit from at least 1 shim and adjustment of Pilot Screws. Add a K&N and another shim would seem logical, add pipes and another shim might be logical. Along at some point changing Main Jets and possible Needle Jets. The #110  Mains have me curious since that is the only other option Honda shows.

I don't know if Honda dealer would be able to shed some light on the two Needle Jets, or verify one is for the CA. model.     

At some point Allen, i would be willing to do some testing, as you mentioned. I like to think it through first to limit the work. Hopefully nail it on the first couple of tries.   

[Greg Cothern]

Here is what I usually go with:
BONE stock Magna add a shim kit, adjust pilot's to 2 3/4 turns out.
Aftermarket exhaust also add a jet kit, adjust pilot's to 3 turns out.
K&N with the above adjust pilot's to 3 1/4 turns out.
V&H's seem to flow a bit more air than some of the others, I go with an additional shim (1 stock shim and 2 extra DRP shims) and pilot's out about 3 3/8 turns out.
V&H with stock air filter, seems most are pretty close with stock shim a 1 DRP shim and 3 1/4 turns out.
I am still playing around with the Supertrapps and the Dyna Jet kit (which was already there from PO).

[roboto65]

I am not near my bike but cannot remember which carbs we have on our babys. Mikuni or Kehine someone knows LOL

[Chad in Michigan]

I just posted on the vaccuum leak thread if you want to check it out. i did up the pilots to 45 and the mains to 112 and i am at 3 turns out, and 3 shims on each needle.  but the low end is just a tad rich when cold. I don't have to use the choke at all, and the throttle is crisper when cold and slightly fades when warm so i think it's just a tad rich on the low end.  you would not believe the torque, super punchy midrange and unstoppable top end. i have k&n, vance and hines exaust, dyna 3000 ignition module, dyna coils, dyna 8mm wires, pingle fuel petcock, eliminated the vacuum shutoff valve, added a pingel fuel filter.
stock gearing right now at 15/40 also.  hope this helps. -chad

I was going to post this under the Vacuum thread than decided it is better to start a new thread.

What I am reading under the "VACUUM LEAK" THREAD is a bike with a K&N and pipes benefits from a 3rd shim, is that correct? If that is the case it should help on all 3rd generation bikes with the same set-up, correct?

What has been anyones experience?

Has anyone upped the pilot jet? Pilot jets are too small with the 3+ turns out, how much difference that will make, I don't know.   

Are there starter jets in these carburetors or what acts as the accelerator pump?

Tried different needle jets?

Anyone taken the main jet higher than a 105, what's your take?

I have not researched any of the above and somewhat asking these questions premature as I am not ready to take the plunge and dedicate the time yet but this info will help form some opinions.

In the future I had planned to buy various sizes of jets and spend a few days tuning mine in but this might give insight as to what will work or what has been tried.

I will change the above as "I would like to in the future".  Time and needs are always the issue.

Any input you have will help us all out, so speak your minds, opinions and experiences.

[Chad in Michigan]

FYI:

JETS:

112 Main:
Mfg Product Number: 99101-GHB-1120
Description: JET (#112)           for  Honda
Order Quantity: 4
Unit Price: $4.83
Total Cost: $19.32

110 Main:
99101-GHB-1110

45 Slow Jet:
PRODUCT INFORMATION:
Part Number: 99103-MT2-0450
Description: JET (#45)            for  Honda
Order Quantity: 4
Shipped Quantity: 4
Unit Price: $7.53
Total Cost: $30.12

42 Slow Jet: 99103-MT2-0420