Jet Kit Needed???

[packge33]

Hey folks,

Long timer reader, first time poster.  This site is great for info and thanks for making me an honorary member even though I live in AZ....

I have a 97 magna and have just complete the muffler mod (cut out the baffles).  It sounds GREAT!!! I also have installed the K&N filter. 

Should I also do the Jet/Shim Kit from Dave Dodge?  I have quite a bit of 'popping' during deceleration.  I have not noticed a "flat spot" during acceleration, though...

You thoughts and thanks in advance for the help!!!

Mike

[TLRam1]

You bet you should do the Jet-Shim kit.  The simple answer is Yes, if you are more into the tech side read below.

In this thread this issue was discussed in more detail. Results below. I think I have the Shim count correct, I reread it so many times and I was on a different planet from everyone else regarding the number of shims. I probably need to reread again to make sure.

Pay attention to your altitude.


http://www.magnaownersoftexas.com/forums/index.php?topic=2119.0



This is where we are at currently.

From my readings and input from Magna owners, a stock Magna needs the DD Kit.

Pilot Jets on all could stand a change to #42 but it's on the bubble and works well enough with the stock #40's installed. Personal choice, depends on how much you want to spend and how finicky you are.

I think 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

DD Kit which includes

Shims – 1 (additional)

Mains #105

Pilots screws 2 ¾ - 3 Turns out.

Option - #42 Pilot Jets

__________________________________________________________________________


K & N air filter

Stock Exhaust

DD Kit which includes

Shims – 2 additional

Mains - #105

Pilots screws 2 ¾ Turns out

Option - #42 Pilot Jets

Order another set of shims from DD so you can have a total of 2 additional shims per Needle Jet.

_____________________________________________________________________________


Currently working for a MOOT Member

K & N air filter

Cobra Exhaust

DD kit which includes

Shims – 2 (additional)

Mains - #105

Pilot screws 3 Turns out

Order another set of shims from DD so you can have a total of 2 additional shims per Needle Jet.

Option,

Not tested, IMO, I think you could comfortably change the Mains to #107.5

Probably should change to the #42 Pilot Jets

_______________________________________________________________________________


K & N air filter

V & H exhaust

Shims – 2 (additional)

Mains – #110 or #112

Pilots - #45

Pilot screws 2 ¾ turns out

____________________________________________________________________________


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.

[Magnum Magna]

Welcome to the Moot.  I kind of like the popping so the person behind me has an audio indicator I am slowing down.   I was about to change to the K & N filter but I did not, but next filter change I will goto the K & N.  I also don't have the "flat spot" during acceleration, I believe the previous owner shim the carbs. 

[Herman]

Mike,

Where abouts in AZ do you live?  I'm in Gilbert. 

I did the jet/shim kit from Dave Dodge and it wasn't too hard.  I've got a 97 also.

[packge33]

I am down in Tucson....

I would like to do the shim/jet kit since I want to remove/clean the carbs anyway.  Not to change the subject, but am I going to need the special vaccuum gauges that I have seen on other posts that shows the readings for all for carbs simultaneously, or is the "bench sync" goo enough?

Thanks again,

[packge33]

What comes in the DD kit?  I notice that some people put more than one shim in each carb... does the kit come with multiple shims, or do you have to order multiple kits?

Thanks

[TLRam1]

The carbs probably will not need sync-ing but it doesn't hurt.

DD kit comes with 4-105 jets and 4-shims. You can buy more shims from him without buying the jets.

[lragan]

...  Not to change the subject, but am I going to need the special vaccuum gauges that I have seen on other posts that shows the readings for all for carbs simultaneously, or is the "bench sync" good enough?

Thanks again,

I bought a "mercury stick" consisting of four calibrated tubes, four plastic tubes and a bottle of mercury.  You need to be careful with the heavy metal mercury, but it works great.  I recommend syncing the carbs with something similar, if not this setup. 

[dgc67]

While I am not positive on the cost exactly, the sync tool is not too expensive.  Also, the newer ones no longer use Mercury.  So they are safer to use.  I have one with a blue liquid (not mercury of course) in it and it works great.  I got mine as a gift a year or so ago.

[Greg Cothern]

Sync'ing is for the most part not necissary unless you have torn the carbs apart from each other.  OUT of the several I have done they were all pretty close and could not tell a difference in performance when finished.  Besides the in sync range specs are fairly broad in my opinion.

I see more bang for the time/buck out of shims and pilot jet adjustments.

I would suggest not going with the K&N and only shimming the carb needles with a pilot jet adjustment.  HOWEVER if you wish to utilize the K&N then I would certainly do the jet change as well.  IN my sons 96 he has the K&N, Muffler mod, and DRP 105 jets with a additional shim.  HOWEVER he would probably benefit from a larger main jet 107.5 jet would be appropriate I believe.  The single shim seems to be pretty close.  See attached PIC, it is a bit lean for his riding style, which is highway speeds most of the time and pushes the RPM a bit into the upper ranges.

[attachment deleted by admin]

[packge33]

My riding style is fairly conservative and mostly in town, with an occasional short highway trip...

Greg, when you said that your son has the 105 kit and an additional shim, does that mean that I need to order another set of shims (using two) when I order the DD kit?

Fairly new to this, so thanks for the patience....

[Greg Cothern]

Nah, I believe the shims in the kit will get ya what ya need.   

[BA]

I used #4 electronic washers from Radio Shack.  I got a bag of assorted sizes (20 of each) for less than $4.  I did measure them with a caliper to ensure the thickness was consistant (5 of the 20 #4 washers were quite a bit thicker than the others).  Added two extra to each needle, upped the mains to 105s, and have the K&N filter.  Everything else is stock.  Chad helped with this and it's running great.  Thanks Chad.

[L J VFR]

I too think i need to go in and add 105 jets. i kick myself in the butt because the last time i had the carbs off, i added the extra shim for a total of 3 but did not change jets to 105     Maybe this week sometime....