Triumphrat

eviltwin415 · 01-08-2009, 11:32 PM

Hi all, this is my first plea for help here and its gonna be long winded so please bear with me. Let me start by saying that i am a complete novice with a fear of tools and its a miracle what i've accomplished so far

also be aware that there is an excellent chance i won't know what you're talking about if you mention something i haven't talked about here, because this is the extent of my motorcycle knowledge.

ok, i got my burgess pipes on. I'm still using the airbox because apparently that piece of info matters. i did buy a k&n filter though i started with 125 mains and the stock needles (i assume stock, i got the bike used/salvaged/theft recovery). i was running super lean. i upped it to 130 mains and was going to use the thruxton needles, but when i removed the needles i saw they were almost identical to the thruxton needles just a tad longer, so i used the slimmer needle from the dyno jet kit i bought along with the pipes on the middle shim (right term for the length spacers at the top?) because i thought this would allow more fuel. still very lean.

My next step is where i need advice. i figure these are my options:

#1 shim up the needle
#2 turn the air mixture screw with that D tool thing-- i have not messed with this screw at all- how can i set it to stock and which directions to i turn it, and after stock which way shoul i go if it's lean?
#3 scrap the 130s and use the jets that came with the dyno jet kit (only go up to 120)
#4 use an even bigger main

i called the local shop and the guy said that what i had read on the forum about 130 jets and thruxton needles was probably because people had removed their airboxes and that i should follow the dyno jet instructions. so #3 isn't even my idea.

thanks for reading! btw, any sfbay area people on here?

eviltwin415 · 01-09-2009, 12:14 AM

did i do something wrong?

Ventura · 01-09-2009, 05:55 AM

First of all, welcome to the forum E.Twin,
good to have you along!!

And now to your plea for help...........

Firstly, how do you know your running lean?
If in fact you still have the airbox fully intact, which your post seems to indicate, you are more probably running rich with 130's fitted.
Can you clarify in what state the airbox/intake is in?

You're also running a DJ needle on the middle clip?
This will enrichen it further.
One thing to beware of is that the jet sizing of those in the DJ kit differ from the original Keihin sizes.
There's a comparison table in the "Great sources of info" sticky at the top of Tech page.

With the mixture screws you wont be far wrong if firstly you screw them all the way in, then open them equally to 1.5 turns open.
Now gradually keep opening them (equally) a little at a time until the tickover starts to falter.
From this position turn them back in 1/4 turn and you'll be about there.

I'd be tempted to suggest that you firstly get everything jetted and set up for your airbox/exhaust configeration using stock needles etc then move on from there.

And if the airbox is standard then you certainly have a lot of moving on to do!!

V.

eviltwin415 · 01-09-2009, 12:19 PM

Thanks for the reply Ventura! ok, what do you mean by "what state is the airbox in? the smog stuff i believe has been removed. i think i'm running lean because my plugs are white.

what you said is prety close to what the mechanic at the dealership said, but completely different from what other threads said (if my understanding is correct. it makes sense that i would be running rich from what you both said, but the plugs say different. i'm gonna try the thruxton needles first and see what happens. am i correct that the air mixture screw wouod be stock at 2 1/2 turns out? if the thruxton needles don't help i'm going to try just the parts fromthe dj kit, maybe the 116 jets to starts and the dj needles.

what do you mean by "until the tickover starts to falter"?

Ventura · 01-09-2009, 01:02 PM

Quote:

Originally Posted by eviltwin415

ok, what do you mean by "what state is the airbox in?

What I was asking was, is the airbox in its original condition withouts mods?
Or has the snorkle and/or restrictor been removed?
Its the answer to this which will best determine what jetting would be correct

Quote:

Originally Posted by eviltwin415

am i correct that the air mixture screw wouod be stock at 2 1/2 turns out?

I believe thats correct and it should be your benchmark setting to aim for.
But if any alterations have been made from stock then this may have changed slightly.
Hence the starting at 1.5 turns out and slowly increase

Quote:

Originally Posted by eviltwin415

what do you mean by "until the tickover starts to falter"?

When the tone of steady tickover starts to falter/misfire/become unsteady..........

Everything seems to indicate that you should be running rich (if the airbox is intact) apart from the colour of the plugs.
Thats why it may be worth considering putting the stock carb components back so the settings etc can be verified.

Hope you get there in the end!

V.

killian101 · 01-09-2009, 02:00 PM

"#1 shim up the needle
#2 turn the air mixture screw with that D tool thing-- i have not messed with this screw at all- how can i set it to stock and which directions to i turn it, and after stock which way shoul i go if it's lean?
#3 scrap the 130s and use the jets that came with the dyno jet kit (only go up to 120)
#4 use an even bigger main"

PokeyJoe helped me with my set up. I went with 120 and 40's (no shim...or extra shim), sans the restrictor plate, new bellmouth, K&n filter, no AI, and Ca EVAP system. Over all, the bike runs a bit lean. I plan on going to 130's and 42 and minus an airbox...then see where that leaves me.

But with an intack airbox, a safe bet would be about 130's/42 (maybe a shim)...at least thats what Commando Specialties says on their web site

eviltwin415 · 01-09-2009, 11:01 PM

i thanks for both your replies.

Ventura, i don't know about my airbox mods, but i believe my smog stuff has been removed. as for that mixture screw, i was having trouble figuring out where completely closed is to try to set it to stock. i don't know if it was slipping out or what, but it didn't seem to just stop anywhere whichich i found troubling

Killian, you went over my head a little bit with this: "I went with 120 and 40's (no shim...or extra shim), sans the restrictor plate, new bellmouth, K&n filter, no AI, and Ca EVAP system. Over all, the bike runs a bit lean."

what does the 40 number mean? is it another jet? i also don't know what the restrictor plate, bellmouth, AI, and Ca EVAP sysytem are. i'm guessing the CA EVAP is the smog stuff? it's gone i thing. the restrictor plate and something else with tubing (i'm going from something someone else told me) need to go if they are still on i think.

here's my next move. i originally learned of these pipes from a guy who said he also used the DJ kit, so i'll leave the dj needles in and follow what he said which is: use the DJ kit jets (not sure which), and remove the restrictor plate and tubing or snorkel that i've heard about if i can figure out what it is. at least that way i'll be taking i person's approach and not pieces of three different people's. if this doesn't work i'll try another, right now it just seems easier to only replace the jets. BTW, i don't know if everyone else has done this, but i replaced all those philips head screw on the carbs with allen screw and my life is much easier.

thanks for all the advice so far guys, i'll report back. luckily the woman is out of town which means i can mess with this all weekend instead of writing my students' final exams.....

Ventura · 01-10-2009, 07:20 AM

Quote:

Originally Posted by eviltwin415

..........right now it just seems easier to only replace the jets.

The only way you can accurately determine what size jets to fit will be based
on knowing what mods have been carried out on your airbox.

Take some time and search this forum to gain a little knowledge of your bike and in
particular the construction of the airbox.
You'll then be able to see in what state yours is, and then rejet accordingly.
Its preferable to know what your doing and, more importantly, why your doing it, before you start.

All the info you need, and more, is here.
Search for "airbox", "restrictor" and/or "snorkel" and there will be hunreds of threads to sift through.

Good luck!

V.

meatwagon · 01-10-2009, 02:42 PM

You say you are running lean....when are you running lean? You need to know the correct procedure for reading the plugs.To determine if the main jet(s) are correct you need to run at full throttle for about 1/8 mile or so ,then kill the ignition,pull the plugs and read the color. you cant figure out the main jets by idling the bike and then pulling them...
DynaJet uses their own sizing system and do not confuse this with Keihan sizes,they are not even close to compatable....let an expert determine the sizes of jets and needles if using a dynajet system.
the 40 # refers to the pilot jet size...the pilot jets are used in the idle circuit and low speed running.
needles control the mid-throttle response...where you do 90% of your riding.Very important to get this right.
The K+N filter really wont make any difference in tuning,flows air the same as a stock paper filter.dont make any adjustment for it.

google Jenks' tuning guide...and read it untill you understand it.

FWIW ...you haven't said what model and year you are riding.The burgess type pipes need about 1 or 2 size increase in main jet.(if you have 120 mains stock ,this means 122.5 or 125) if you have no other mods to intake.If you pull the snorkle,add 1 more size to the main and 1 shim to the needle.these are general notes....use dinqua's tuning guide or jenks'....they know.