Which jets to Change???????

I had my bike Dyno'd at a local shop. They said I was running pretty rich and could probably go up about three sizes in my jets. I called the next day and discussed with a technician. He said go DOWN a main jet size instead of going up on main AIR jets. What do you guys think?

 

How in the world did you get your bike to run rich?!?!?
Most mods peopld do to their bike cause them to run lean. I know most people change the fuel jets to change the mount of fuel being pulled up through the main air jet stream. But there is no doubt some effect of changing the air jets, but I haven't seen anyone trying it on the forums.

If you've done mods that would classically cause a bike to run lean...but you are running rich, make sure you don't have other problems (like the enrichment circuit dumping fuel in when it shouldn't). If you're running rich because you already re-jetted...then ignore my questions as to HOW you ended up running rich.

Maybe just throw on some PODS to lean it out <----just joking

 

Bane,

Is your 650 bone stock? If so it could be as simple as syncing and adjusting the mixture screws OR changing out your air filter for a clean one.

Otherwise if you have done modifications, those mods need to be listed for proper diagnosis.

 

can you even get different size air jets and what air jets low or high
hows it feel on the road?
remember rich is better than lean

 

Starts great, never a problem with how it runs.
MODS INCLUDE: K&N air filter, 4-1 with no baffle, head was shaved, dyna coils with 8mm wires.
Spark plugs are always tan never dark or white. Colortune showed the correct burn but their "professional" machine says otherwise.

 

QUESTIONS:
1-did the shop use a wide band o2 guage if so what do they consider rich
2-how many .000" did you have milled off
3-did you use an oem head gasket

I'm not sure I'll be able to help you out I'm just curious about the head mill mod.
Thanks,
James

 

.020"
stock gasket
rich is below 12 and they say wide band but only measures between 10 and 18 so I'm thinking not.

 

You can't make the changes necessary to get Maxed on the Dyno and still have a Bike that will give you Low-end Performance, too.

Dyno Tuning is going to correct your Jetting for W-O-T, ... Only!

If you had a Fuel Injected Bike, ... The Software could be adjusted to correct SEVERAL Parameters that CANNOT be changed on your Bike without affecting some other way the Bike Pefrorms.

Fuel Injection Software can be programmed to change:
F/I Advance -- Yes |--| Your XJ -- No
F/I Pulse Width -- Yes |--| Your XJ -- No
F/I Lamda Feedback -- Yes |--| Your XJ -- No

The Fuel Injected Bike can have Mixture and Power Changing Settings changed with a couple of Mouse Clicks On the Fuel Injections Firmware settings and returned to Default without touching the Bike.

To attempt to Alter Jetting (( ONLY )) you have to Pull the Carbs and dismantle them for every alteration ... Strictly Limited to MIXTURE.

The Dyno Operator should have known this ...
Told you this ...
Disclosed this ...
Gave you a Heads-Up about NOT being able to change Values ...

BEFORE putting your Bike through the Run and giving you what really amounts to: ...

Bad Advice.

 

I've been following the "if it aint broke, don't fix it" advice this far and was thinking that I should stay on that course. Between the colortune, spark plugs and a healthy running bike, seemed like changing anything would be a recipe for disaster! I appreciate the good advice! The operator was NOT the guy who "helped" me the second time but either way oh well. I was rather disappointed in the HP and TQ rating but then realized that the stock rating for HP I keep seeing is at the crank not the rear wheel. I'm just gonna keep ridin' her this way, seems to agree with both of us.

 

What did she turn for ratings?

 

If you are inclined to do the Tuning you CAN do for getting the most from your Bike:

Vacuum Sync for all four -- Perfectly Synced

De-oxidize and Polish the Diaphragm Piston Bores to a mirror finish. Will vastly improve performance.


Tweak - Plug Chop:
Monitor your Burn very frequently. Adjust (as necessary) individual Cylinders for a "Performance-Lean" Condition.

((Add a new --> Longer <-- Vacuum Hose to the Petcock.
Add a new --> Longer <-- Gas Line from the Petcock to the Carbs, ... to make it EASIER to Tweak. Fabricate a TUNING SCREWDRIVER.

Take a Screwdriver that you can sacrifice and Modify it for Tuning ONLY.
Cut the Shaft down to 2-Inches.
Cut the Handle off leaving "A Small Handle
Chuck the Modified Tool in a Drill and SAND it to a Customized Grip for Tuning.
Gring and Fabricate a TIP on the Shaft that FITS the Slot on a Pilot Mixture Screw --- Perfectly. --> Width and Slot Depth)

Become a Frequent Tweaker.
Find the Sweet-Spot where the Pilot Mixtures can be adjusted from Performance Lelan to Cool Running Rich and get so good you can make the adjustments in under two minutes.)

 

I got 56.43 HP and
36.89 for TQ

 

So what ended up happening with your bike?

 

Bain has not been here after 2013 try starting a conversation with him he may get the email notice and reply

 

His inbox is full -_-