JET Question

[zleehw]

Ok here it goes - :shrug:

Stock engine
Stock Air box wo/ Lid - K&N Filter

D&G Pipe and silencer

What size main jet? :confused:

And what else should I know about card settings and adjustments?

:hug:

Thanx
zleehw

[Red Rider]

What's the temperature & elevation where you're riding? I see you're in San Diego, and that's mostly 0-200' above sea level, but is that where you ride? Jetting by forum will only give you a baseline to start with. To get accurate results for your bike, you'll need to do some plug chops.

[brotha-rod]

was your bike running fine the way it was before pipe if so is the pipe all you did sence you should always jet after each mod and not do multiple mods before jetting, going with just a Dg pipe do a ride and feel if the bike revs out but then looses power its probly lean go bigger if the bike bogs and crackles its rich go smaller jetting is best done by ride and feel first and then try fine tuning with plug chops.

[wild200x]

http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml

try this link. i just dug it out of an old thread for you. the link was posted by Troll in a thread posted by GdKarma as he was having isues w/an 83. i think there is enough info in there for ya to get going very well.

[zleehw]

Ok,

Went to gordon's well on new years day. 70 to 75 degree's
Here is how the bike was set up -

Stock engine
Stock pipe
NO AIR BOX - Just a K&N filter on stock snorkel

And the bike ran good, except at high end it would lean out and while hitting bumps it would finally get the power back and go balls to the walls.

I learned by talkin with techs at duncan briefly that I need to put the stock box back on and leave the lid off to get better forced air flow...So I ordered a box off eBay and it will be installed tomorrow.

While waiting on box, found cheap D&G exspansion chanber and silencer, cleaned it up and installed.

Now before I head out to gordon's for Pres weekend...want to have bike in best possible set up...so only need to adjust at sand.

So - I was told today to get a 40 or 42 main jet and go to setting 2 on the clip and follow the tune up steps in the owner's manual for the other carb settings...Hope fully you now what that means...


So with this info - Hope it helps you understand where I am at...NOT TRYIN TO BE A RACER.....Just want my bike to RUN and then fine tune at sand

zleehw

[3razors]

What year make and model bike are we talking about here? Is it a stock carb?

[Rex Karz]

ZE PLUG ! Vot doez ze plug look like ??????

Oh yeah, what kind of trike?

[Rex Karz]

Isn't 40-42 a pilot jet? The power increase on the bumps makes me think it might have something to do with the float. What are you running right now?????? They all start somewhere....... with (if I read correctly) the mods (From Stock airbox to straight filter, Stock pipe to DG) You could start with just going up 2 to 4 sizes bigger than what You have, then by reading the plug and the feel make changes. BTW, make sure you change the main jet first, then make changes to your pilot jet.

[zleehw]

I talked to a 250 four wheeler guy today,

He sold me a 155 main jet today and instrucked me to go to clip position 4 with this bigger main jet.

So to help all of you understand.

1985 Honda ATC 250r
D&G pipe
stock carb
"the float is sticky, went and turned my petcock on and gas flowed from every overflow line...

So now takin carb off bike...removing bowl and cleaning it out and replacing with new main jet and resetting clip to settin four.

[3razors]

Absolutely make sure to get an outerware for the K&N filter, if not fine dust particles are gonna be in your motor. For best protection get an UNI.

155 main will probably only run correctly with the airbox lid off.

[likestrikes]

I'll tell ya from what I've been thru that no one can tell you what to run for jets. Your best bet is to start fat (rich) and work your way down so you don't damage anything. I'd also put the needle in the center to begin with....

All of our mods are different:

My 86/87 200X motor is now at about a 270 main and a 50 pilot, center clip, airscrew 1 turn out and thats running a Mikuni 28MM flatslide and full race gas.

Those jets are BIG and for some reason, this motor just loves it!

Razors read an article where they used a 210 main and 20 pilot with the same carburetor and aftermarket exhaust. I also have porting, lightened flywheel, full race cam and a 12:1 piston.

That to me, explains the difference but it shows how much things can vary.

Yesterday with these jetting settings the motor was cutting out terribley on topend, so bad that I felt I had an ignition problem. Then I took off the air box lid and it took off like a bat out of hell......

Start big, center clip, 1.5 turns out and work from there but I will say this, it is not easy and it can't be done fast unless you are very fortunate to have picked a good combonation of jets!

GOOD LUCK!!

[zleehw]

Todays accomplishments....

New bike settings --

D&G Exhaust installed
New Spark plug
Cleaned carb float, bowl, and polished the needle valve port
Installed 155 main jet
---- Going to set all other screws in accordance with owners manual

The only thing waiting on is the new stock airbox wo/ lid

So we will see on presidents day weekend at gordon's wells

Will try with air box and see if it cuts out then maybe wo/ airbox...

Thank you for all the tips.

[jenndnn3]

I would add the 158 and 160 as well as the 152 and 150 jets to your toolbox that goes on the trip with you..

If you have not done so already..

Have a fun safe Trip!!


Oh yeah just outta curiousity what were you jetted at before.. (sorry If I missed that)

[zleehw]

My carb was completely stock....jet was original one....

Thanks, I will go purchase a few diff sizes for trip