Drilled out stock Exhaust carb issues

[dannymax]

My first question would be did either one one you guys take the pilot jet out of the jetblock? When you turn that a/f screw and nothing happens IT IS CLOGGED.
There is almost nothing you can spray or run through there to completely unclog it.
I have used the smallest guitar string you can find to get them unclogged and i have a jet tool.
It is the smallest passage on the entire bike and the most problematic.

I would modify this to say it is USUALLY clogged....there are other factors affecting mixture screw sensitivity.

 

[D-Max2012]

Thanks guys for all the help... You guys rock..

On the question of the little plastic indent on each needle assembly.. I took the time to make sure that the little registration protrusion is seated in that little hole next to the needle's opening in the slider.

I had the adjustable needles last year. I tried all positions trying to remedy this problem. Also on each, I tried the 0.30mm shim under each position tried. So if you did the math.. 5 positions trials x 5 shim trials = 25 times I broke into the carbs to try different needle heights.

When you guys adjust your A/F screws, do you hear a big change on each carb?

On my bike, if I close either #1 or #2 cylinder's A/F screw, the engine's rpm changes greatly. Even greater change is noticed on #2 than #1.

I was trying different settings over the weekend and adjusted #2 to get a base reading.
When I closed it, the engine went down to around 500 RPM from 1100 idle then died out. I then put it back to 2 3/4.. It went back up to 1100.

When I closed #1, RPM dropped down to about 800. Put it back to 2 3/4

When I closed #3, I could not hear the RPM change - put it back to 2 3/4

When I closed #4, I barely heard the RPM change.. It may have gone down too 1050 at Idle. Set it to 2 3/4.
I expected #2 to give a big change since its the master cylinder, but I did not expect the 3 and 4 not to show much of anything.

 

[D-Max2012]

D-Max2012,
When your bike stumbles at the 3500-5k....does pushing the choke 'full' help? Mine clears right up....idles up of course, but no more sputter/stumble with the choke on full.

I have not tried running the choke once the engine was up to OT. I've only used it when the engine was cold.

My first question would be did either one one you guys take the pilot jet out of the jetblock?

I have, when I was cleaning everything. After the shotgun, compressed air, seafoam did not resolve anything, I broke everything down and used an ultrasonic cleaner.. the cleaning solution started off looking like clear lemon water, yellow in color. I broke down each carb individually and cleaned them.. The cleaning solution looked like mud.. I did this procedure twice on each carb.. 2nd time water was clear.

 

[dannymax]

Could you see daylight thru the pilot jet?

U/C cleaners, and even heavy duty carb cleaner baths won't clean out plugged pfj's.

 

[D-Max2012]

Could you see daylight thru the pilot jet?

Yes.. Held all parts that had micro holes up to a light, to make sure all was clear.

 

[dannymax]

Yes.. Held all parts that had micro holes up to a light, to make sure all was clear.

:thumbs up:

 

[toytime]

I did not cut off the stock needles to get more shims.... asking the question as it appears in photos the Canadian needles/slots/clips - would have more range. I did shim ~.020.... no effect.

My logic for shimming needles - is the sputtering at the 3500-5k goes away when the choke is set. Doesn't this mean - needs more fuel? I.e. - shim needles? I don't think it is the mains (I have stock mains I believe).... since past the 5k rpm in whatever gear.... runs strong.... and the Vboost at 6k kicks in as I would expect, but what do I know.....this thing isn't running right yet through the range! :-(

Could plugged PAJs cause the stutter/sputter at the 3500-5k we have been talking about?

I haven't pulled and opened the carbs yet.... I was hoping I don't have to. But if I do... I want to learn as much before this so I don't get into a pull/reinstall circle jerk like I have heard can be the case with these things.

Appreciate all the feedback - good (or sad I guess) to hear I my bike's carbs aren't the only pain(s) in the A$$ out there.

 

[Traumahawk]

Well a plugged primary fuel jet......the A/F screws....will. By the book the A/F screws affect 0-4000 rpm.....but in reality its 0-3500 to 4500.

The shotgun worked for me when I had to do it.....because I have an air compressor, and cranked it up to 120 psi....and I have a blow gun tip, that I used to shoot air into the carb. After that I had brown gunk come out of PAJ2.

If your using canned air...etc, I dont think that would do it.

 

[Traumahawk]

Thanks guys for all the help... You guys rock..

On the question of the little plastic indent on each needle assembly.. I took the time to make sure that the little registration protrusion is seated in that little hole next to the needle's opening in the slider.

I had the adjustable needles last year. I tried all positions trying to remedy this problem. Also on each, I tried the 0.30mm shim under each position tried. So if you did the math.. 5 positions trials x 5 shim trials = 25 times I broke into the carbs to try different needle heights.

When you guys adjust your A/F screws, do you hear a big change on each carb?

On my bike, if I close either #1 or #2 cylinder's A/F screw, the engine's rpm changes greatly. Even greater change is noticed on #2 than #1.

I was trying different settings over the weekend and adjusted #2 to get a base reading.
When I closed it, the engine went down to around 500 RPM from 1100 idle then died out. I then put it back to 2 3/4.. It went back up to 1100.

When I closed #1, RPM dropped down to about 800. Put it back to 2 3/4

When I closed #3, I could not hear the RPM change - put it back to 2 3/4

When I closed #4, I barely heard the RPM change.. It may have gone down too 1050 at Idle. Set it to 2 3/4.
I expected #2 to give a big change since its the master cylinder, but I did not expect the 3 and 4 not to show much of anything.

One question that I have.....didnt the PO basically do a stage 1 kit....or stage 4 kit to the bike before you bought it?

 

[D-Max2012]

didnt the PO basically do a stage 1 kit....or stage 4 kit to the bike before you bought it?

When I brought the bike, I knew nothing about these carbs.. Plus the PO spoke very little English.. I had to have one of my Spanish speaking co-workers translate. I've been learning as I go. plus funds are extremely tight so, I have to do all the work myself.

I have not seen any comment on when guys adjust their A/F screws does the RPM change and how by much?
Reason for asking, If everyone's A/F screws makes their engine loose RPM when adjust any one of the 4, that would lean toward a blockage on ours.

 

[Traumahawk]

Well the reason why I asked....and that was a typo....it shouldve been stage 1...or stage 7....there is no stage 4 for Vmax.

I wonder if the slides have been drilled....which is common on stage 1..or stage 7. If the slides have been drilled...it would increase the fuel requirements at 3000-4000 rpm.

I adjust my screws....where it runs well, BUT...after I drilled by slides....I actually had to richen up the screws a bit....because I then had a little bit of a lean spot there, because the slides and needles were reacting sooner.

The regular Vmax....the A/F screws are 2-4 turns out, and with stage 7 kits....etc...maybe up to 5 turns out.

I will PM you.

 

[thor_eyerdhal]

Yes I have just made some tests with stock slides and springs vs S7 springs and drilled slides. The AFR show richer results with stock parts...
With slide drilled ans S7 springs, the slide open sooner and quicker, since air react faster than fuel => leaner "spot" during a short time.

Adjusting this with A/F screws is almost useless since the idee circuit stop working in this low vacuum condition..You have to set it out of range to feel some results.

Better to adjust the needle or..Going back with stock spring

 

[D-Max2012]

Any comments on about RPM change when adjusting your A/F screws?

Did you guys notice a significant RPM change while adjusting ANY of the 4 carbs, or just a couple of them?

If a working bike has significant RPM change when ANY 1 of 4 A/F screws are temporarily closed, I'd have to think that this would mean that there is a problem with our A/F screws or passages, since only 2 of the 4 carbs show a significant change when the screws are temporarily closed.

I spoke to Traumahawk the other night.. Really nice guy.
We spoke about different possibilities. I will be doing more work on the carbs this weekend.

 

[Traumahawk]

What I am thinking is there there would be a significant drop when the the A/F screw is all the way in. You are cutting off the fuel to the cylinder...creating a "dead cylinder" just like idling with a spark plug wire off.

I know from previous stories on here.....the Vmax will still idle even with 2 cylinders not firing...and I had to do a shotgun last year because 1 fuel jet was clogged, and I couldnt really tell a difference in idle. I found out that i had an issue because of a lean pop out the exhaust at 3500-4500 rpm.

 

[D-Max2012]

(From Original Post) - I tried to adjust, but noticed the 2 screws in the carbs for the front cylinders - do nothing. I can turn them all the way in and the engine does not change idle or stall.

What I am thinking is there would be a significant drop when the A/F screw is all the way in. You are cutting off the fuel to the cylinder...creating a "dead cylinder" just like idling with a spark plug wire off.

Exactly..
That's why I would like to know, if others have a significant drop in RPM, when closing any 1 of the 4 carbs A/F screws.. If they do, AND, they have a smooth transitioning throttle response, then I know that we're missing something. Maybe our's are partially clogged??

 

[toytime]

Great to hear you guys talking about this.... I have A/F screws 2 and 4 that make no difference when turned all the way in. Coincidently...if I pull those 2 plug wires at idle - runs the same... so yes - sounds like 2 plugged idle circuits. I also notice when I ride, I feel the 2 cylinders kick in as I come off idle and the throttle opens. But does do the sputter/popping as I cruise at 3500 -4500, buts opens/runs fine past 5k.

I have noticed popping on throttle closure/slowing dow, but I think that is 1 and 3 because I have tried opening all the screws to 3.5 turns (running Seafoam in gas), and I had also shimmed the needles - because when I set the choke in the 3500-4500 - all clears up.

I want to try the shot gun again, and remove the shims - but if that fails.... sounds like a carb pull is required to clear some circuits.

 

[D-Max2012]

I pull those 2 plug wires at idle - runs the same...

I have to try that one the ones that doesn't show a change when the A/F screws are closed.
That would suggest that I'm not running on all 4. At least not till I'm past the idle circuit.
I plan to take a temp reading on all 4 header pipes tomorrow.. I'm curious.

 

[D-Max2012]

Getting to the header pipes are easy in the front, but impossible to position the temp reader at the same location on the rear ones... So, I did a cylinder temp check instead.
All 4 running close to each other once warmed up.. (Temp needle at 1/2 range on gauge) - Positioned the digital thermometer at same location on each head. Right between the valve covers

163' #2
164' #1
170' #3
164' #4.

(gotta check why #3 is running a bit hotter than the rest).
So, I think I'm firing on all 4 at idle.

 

[thor_eyerdhal]

Seems to be close(great) but the water flow in the block equalize the cylinders temps...

 

[toytime]

Hey All..... I was the originator of this chat - and have good news to report.

As I had mentioned, post my 2005 purchase, I had tried the shotgun and peashooter initially and neither of them seemed to have an effect on what I believed was 1 maybe 2 idle circuits not functioning. Causing sputter/coughing in the 3500-5k range (unless I pulled the choke) - and no airscrew affect on 2 cylinders.

Well - after about 300+ miles and tanks of gas with Seafoam - I tried the shotgun again (and removed the needle shims while in there) - I think I have it running! No more sputter or choke required, and get noticeable affect with each air screw.

With the carbs sunk (I bought the Carbtune) and about 2.75 turns out on the screws - it seems to run damn good! And at idle I get that 'cammed' sound I've read about, and also fast throttle response off idle! Loving it!

One thing I still notice a little - very little (and is probably due to my stock mufflers have the plates removed the 5 holes drilled to 1/2 inch - quite noisy) - when I let off the throttle fast, I do get a little popping. Is this my screws still out a bit too far - i.e. too much gas still in the intake? I have tried turning them in a bti - doesn't seem to affect. I will ride a bit and check my plugs.

Or is it due to the mufflers and the back pressure (or lack of?)

Thanks to all who have commented here to help me get this thing running!