Stumble at high RPM, popping, and cool header
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sdt354
Well-Known Member
The washer belongs there. I like holding the carb upside down and using the casting circle viewed in the float as a guide, them verify with a wet check. Lots of threads on here with pics. What is the V-boost set up? Is it early or full time?
It looks like someone put in a stage 1 kit.
You can actually keep the stage 1 needles, but you will NEED to change the PAJ2 air jets back to 170's, and put the clip on the needles, to the first space closest to the blunt end.
it look like in its current set-up that your running rich.
You can actually keep the stage 1 needles, but you will NEED to change the PAJ2 air jets back to 170's, and put the clip on the needles, to the first space closest to the blunt end.
it look like in its current set-up that your running rich.
sdt354
Well-Known Member
The washer belongs there. I like holding the carb upside down and using the casting circle viewed in the float as a guide, them verify with a wet check. Lots of threads on here with pics. http://www.vmaxforum.net/showthread.php?t=1427
The little diaphragms will effect deceleration. Is there any mod. to the V-boost opening?
The little diaphragms will effect deceleration. Is there any mod. to the V-boost opening?
The V-Boost has not been modified to my knowledge. It comes in at 6000.
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So the needle doesnt look like the stock one? Is it because it has places for the clips to go? This is an 85 model, and from what I read is not adjustablle, (other than adding a washer).
I am a little confused. When I first got the bike, it ran very strong. Should I go ahead and try and tune the bike as is before ordering a set of 170 jets?
Update: So I saw the thread on needles, and it does look like stage 1 needles. It didnt have any clip on it, just the washer. Does this mean it was a ****** install of that needle? How would it function correctly without the clip? Can I just find some e-clips locally to put on there? Should I go ahead and order a set of Mikuni 170 jets? Maybe when I thought this thing was running good, It really didnt show me its full potential!
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Yep, that is a stage 1 needle, and stage 1 kits are notorious for being set up too rich.
I DO believe that you have other issues....IE the pilot jets being clogged, and thats is what the initial problem is. AFTER that, you can tune the bike to run a Helluva lot better.
You can see a pic of the various needles below. The stock needle is non adjustable (except for a set of canadian needles.....which are HARD to find) The stock needle is also fatter, so it will take up space, and not allow as much fuel to flow, so in turn it makes the middle of the fuel curve leaner.
A LOT of people have made the mistake that the Vmax needs extra fuel, and unless you go with an aftermarket exhaust, that simply isnt the case.
So, fix your initial problem, THEN tune the bike (pretty much back to stock) and you will be amazed at how well it will run.
I DO believe that you have other issues....IE the pilot jets being clogged, and thats is what the initial problem is. AFTER that, you can tune the bike to run a Helluva lot better.
You can see a pic of the various needles below. The stock needle is non adjustable (except for a set of canadian needles.....which are HARD to find) The stock needle is also fatter, so it will take up space, and not allow as much fuel to flow, so in turn it makes the middle of the fuel curve leaner.
A LOT of people have made the mistake that the Vmax needs extra fuel, and unless you go with an aftermarket exhaust, that simply isnt the case.
So, fix your initial problem, THEN tune the bike (pretty much back to stock) and you will be amazed at how well it will run.
Attachments
Yep, you need a clip on it, to keep the needle where it is supposed to be.
Looks like the clip is in place, just above the amber plastic spacer.
Also, if you didn't do any tuning that resulted in the bike running as it is now....then tuning won't make it run like it did previously. If there are no internal mechanical failures, then it's an externally created problem....I'd start with a good cleaning/inspection before changing anything....altho I agree with Eric, the PAJ2 looks awful fat.
Also, if you didn't do any tuning that resulted in the bike running as it is now....then tuning won't make it run like it did previously. If there are no internal mechanical failures, then it's an externally created problem....I'd start with a good cleaning/inspection before changing anything....altho I agree with Eric, the PAJ2 looks awful fat.
Ok, I see the clip now. Should I leave it where it is or should I move it to the first spot at the blunt end? I'm wondering if this may mess up the tune with the bigger jets. What is the near stock setting on the stage 1 needles as far as clip placement? Only mod to bike is the drilled muffs. I'm thinking i should buy some smaller paj2's and put this back to stock. Who would you recommend to buy those from?
93max
Well-Known Member
Raising the clip will lean the mixture.
I'm guessing that the way Trauma was saying.
If all that was done to it was drilled mufflers, Id think that's what he meant.
Even slipons do nothing for performance.
That's what I've read.
I'm guessing that the way Trauma was saying.
If all that was done to it was drilled mufflers, Id think that's what he meant.
Even slipons do nothing for performance.
That's what I've read.
Got #1 and #2 carb done today. Set the float level to exactly 1.125. I will mate the pairs together in the morning, install, and do a sync.
Then from what iv'e read, i'll adjust each a/f mixture screw to peak idle.
Take this bitch out for a test drive and see where i'm at at other rpm's.
unk:
Then from what iv'e read, i'll adjust each a/f mixture screw to peak idle.
Take this bitch out for a test drive and see where i'm at at other rpm's.
unk:I'm really thinking that coil was the problem with the stumble at WOT. If this thing runs good tomorrow, I may start moving those clips on the needles towards the blunt end (leaning it out) until the bike doesn't like it. Does that make sense to do?
CORROSION IN THE PLUG WIRE CAUSED THE HIGH SPEED STUMBLE. HAD BAD RESISTANCE READING WHEN CHECKING SECONDARY COIL TO THE SPARK PLUG CAP. CUT 1/4" OFF END OF WIRE GOING INTO COIL. CHECKED GOOD AFTER THAT.
CORROSION IN THE PLUG WIRE CAUSED THE HIGH SPEED STUMBLE. HAD BAD RESISTANCE READING WHEN CHECKING SECONDARY COIL TO THE SPARK PLUG CAP. CUT 1/4" OFF END OF WIRE GOING INTO COIL. CHECKED GOOD AFTER THAT.
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Where I would suggest.....is 1st clip closest to the blunt end. 150 mains (you can get by with the 152's but it will be better with the 150's) PAJ2 170.
That should really wake the bike up.
Yep, that makes sense....because I think you way too rich.
That should really wake the bike up.
Yep, that makes sense....because I think you way too rich.
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Also, check the "Air hole" on the slides, and see if its been drilled. You can use a DD19 drill bit, to see if its been drilled.
Also, look at the length of the springs. see if they are 5 inches, or 7 inches.
Below is the PDF for the stage 1 kit.
Also, look at the length of the springs. see if they are 5 inches, or 7 inches.
Below is the PDF for the stage 1 kit.
Update:
The slide springs are 7" and I couldn't tell if the slides had been drilled. All the holes looked clean.
Got the bike back together and synchronized the carbs.
I left the clip on the needle where it was for troubleshootings sake. I took it for a ride and it stumbles a little when giving it initial throttle (a/f is still at 2.5 out). This really pulls hard from 6000 rpm on. The hesitation on the top end is gone.:clapping: Honestly, the bike is pulling harder at the higher rpms, than I can ever remember.
So, if i've been reading up on this correctly, Im not going to touch the a/f screws till I get this thing dialed in up top. I'm going to go ahead and move the clip on all the needles to the blunt end (leaning it out up top) and see how it pulls. This will, in turn, lean the lower rpms a little also.
If the move on the needle is liked by the bike, then I am as lean as I can be up top with my current jet setup.
Next I can set all the a/f screws to high idle.
Sound like a plan?
The slide springs are 7" and I couldn't tell if the slides had been drilled. All the holes looked clean.
Got the bike back together and synchronized the carbs.
I left the clip on the needle where it was for troubleshootings sake. I took it for a ride and it stumbles a little when giving it initial throttle (a/f is still at 2.5 out). This really pulls hard from 6000 rpm on. The hesitation on the top end is gone.:clapping: Honestly, the bike is pulling harder at the higher rpms, than I can ever remember.
So, if i've been reading up on this correctly, Im not going to touch the a/f screws till I get this thing dialed in up top. I'm going to go ahead and move the clip on all the needles to the blunt end (leaning it out up top) and see how it pulls. This will, in turn, lean the lower rpms a little also.
If the move on the needle is liked by the bike, then I am as lean as I can be up top with my current jet setup.
Next I can set all the a/f screws to high idle.
Sound like a plan?
Re: Stumble at high RPM, popping, and cool header (RESOLVED)
2nd ride with the clips at the first notch on the blunt end. The bike still pulled hard up top with no hesitation. It felt more smooth also, like a different sound. It did help a little on the low end, It doesn't feel quite as sluggish, but its still not right.
I guess I need to adjust a/f screws now. I just hate that it may richen the low end even more though.
Now it's decision time. Should I buy a set of 170 jets or throw a K&N filter in there to give it more air and go from there?
Who can I buy those jets from?
Do I need to re-synch the carbs after a needle adjustment?
I didn't do a wet level float check. Funny thing, when I first got the pump going to fill up the bowls, my #1 carb flooded and went out the vent line. I thought, well, what did I do wrong. Drained the bowl and refill with the pump, and it was fine. I guess it just needed some fuel to get its initial seal.
I sure do appreciate all the help from you guys. I have learned alot about carbs the last week!!!unk:
2nd ride with the clips at the first notch on the blunt end. The bike still pulled hard up top with no hesitation. It felt more smooth also, like a different sound. It did help a little on the low end, It doesn't feel quite as sluggish, but its still not right.
I guess I need to adjust a/f screws now. I just hate that it may richen the low end even more though.
Now it's decision time. Should I buy a set of 170 jets or throw a K&N filter in there to give it more air and go from there?
Who can I buy those jets from?
Do I need to re-synch the carbs after a needle adjustment?
I didn't do a wet level float check. Funny thing, when I first got the pump going to fill up the bowls, my #1 carb flooded and went out the vent line. I thought, well, what did I do wrong. Drained the bowl and refill with the pump, and it was fine. I guess it just needed some fuel to get its initial seal.
I sure do appreciate all the help from you guys. I have learned alot about carbs the last week!!!
unk:It was really windy out on that second ride, so hard to tell if it was better or same, other than smoother and sound. How would you know if the top end is too lean, backfires? It still pops when decelerating.
I see two K&N filter kits. One with one big filter and one with 4. Which is better?
I see two K&N filter kits. One with one big filter and one with 4. Which is better?
Re: Stumble at high RPM, popping, and cool header (RESOLVED)
Float or float needle sticking, sounds like it was a temporary thing and nothing to worry about unless it re-occurs.
Carb re-syncing....it's always a good idea to at least check it when you're doing a lot of WOT runs.
2nd ride with the clips at the first notch on the blunt end. The bike still pulled hard up top with no hesitation. It felt more smooth also, like a different sound. It did help a little on the low end, It doesn't feel quite as sluggish, but its still not right.
I guess I need to adjust a/f screws now. I just hate that it may richen the low end even more though.
Now it's decision time. Should I buy a set of 170 jets or throw a K&N filter in there to give it more air and go from there?
Who can I buy those jets from?
Do I need to re-synch the carbs after a needle adjustment?
I didn't do a wet level float check. Funny thing, when I first got the pump going to fill up the bowls, my #1 carb flooded and went out the vent line. I thought, well, what did I do wrong. Drained the bowl and refill with the pump, and it was fine. I guess it just needed some fuel to get its initial seal.
I sure do appreciate all the help from you guys. I have learned alot about carbs the last week!!!
Float or float needle sticking, sounds like it was a temporary thing and nothing to worry about unless it re-occurs.
Carb re-syncing....it's always a good idea to at least check it when you're doing a lot of WOT runs.
