What did you do to your Vmax today? Part 2

[user 16790]

removed rear exhaust covers and bolts sheared on both, today is drill out and re thread time, why do they use such little mild steel bolts in cast iron that gets so hot, rust seizure is promised, still, might get to put a bit of paint on later

 

[user 16790]

didn't have any M5's long enough so drilled them out to take M6's

 

[one2dmax]

I reinstalled the stock exhaust and put the centerstand back on. There seems to some improvement over the cobras. I feel like it runs better- smoother and pulls harder. I also like the sound better myself. Thanks to Fire Medic and Sean Morley and Mabdcmb for the advise. Free pair cobra slip on available!

And yet some people feel the need to try and justify them. I wonder if he's a Cobra salesman? I don't care either way. I have personal experience that isn't going to be changed any time soon. Sounds like yet another person who validated my similar experience.

 

[V-Four]

There is no way that data is correct? You could not find any stretch of road that would allow you to hold WOT for 13+ minutes

Well, while that does seem strange, it was the 27K+ RPM that I thought was Odd...and was near the limit for only 4 sec...
What am I missing there?

T$

 

[user 16790]

my bike has quite badly pitted forks on the areas between the two yokes but luckily none on the lower parts, I would like to get new stanchions but I don't have the money for them, so my alternative was to get some stainless tube that just slides over the circlips that locate the air adjusters, then cut it to two pieces of required length and polish both bits up, then fit an o-ring top and bottom to keep the tubes in place and I'm pleased with the result

 

[Gbianchi]

my bike has quite badly pitted forks on the areas between the two yokes but luckily none on the lower parts, I would like to get new stanchions but I don't have the money for them, so my alternative was to get some stainless tube that just slides over the circlips that locate the air adjusters, then cut it to two pieces of required length and polish both bits up, then fit an o-ring top and bottom to keep the tubes in place and I'm pleased with the result

View attachment 69839

Excellent, looks great as does your bike.

 

[Mike B]

Finally got around to finishing the gas tank extension pipe, no need to lift the seat anymore

 

[likembikem]

Finally got to ride my bike about 25 miles in the heat (90+) and check out my new COP set up. Worked fine as I had help from a fine member on here. Was having some high temp idle issues which seem to be gone. Carbs probably need a cleaning and sync but I have a noticeable improvement. I also installed a headlight off switch, which I wanted for warmup and when I am working on the bike running etc. I have recently bought a dummy tank also from a member on here to go with my front and rear fenders for a total re-color, and so I can go back. Currently have the Carbon Fiber but my new color I don't know yet.

 

[93max]

I finally got off my ass and clean and and sealed tank, and had Dan do the carbs!
That was yesterday. Today we rode it!
Another happy customer!

 

[Fire-medic]

Finally got to ride my bike about 25 miles in the heat (90+) and check out my new COP set up. Worked fine as I had help from a fine member on here. Was having some high temp idle issues which seem to be gone. Carbs probably need a cleaning and sync but I have a noticeable improvement. I also installed a headlight off switch, which I wanted for warmup and when I am working on the bike running etc. I have recently bought a dummy tank also from a member on here to go with my front and rear fenders for a total re-color, and so I can go back. Currently have the Carbon Fiber but my new color I don't know yet.

Just pull the headlight fuse, quick & easy, no mod needed.

 

[likembikem]

Of course no mod needed, a stock Vmax is pretty cool machine. For some reason they all get mods!

 

[vince99frc]

I adjusted my rear shocks. Took less than 5 minutes. Spent 2 hours trying to get rid of the 4krpm stutter and was unsuccessful. I have done the COPs, adjusted the 4 a/f screws to no avail, and I have resync'd the carbs several times. Problem started when I switched to a freer flowing exhaust. Bike idles and rides through the gears fine if you are giving it throttle. As soon as I try to cruise in 4th and 5th at that rpm I get the stutter. Ok enough of the rant. I will work on it again at a later date. I will most likely have another bike before this issue is resolved. LOL!!

 

[Traumahawk]

I adjusted my rear shocks. Took less than 5 minutes. Spent 2 hours trying to get rid of the 4krpm stutter and was unsuccessful. I have done the COPs, adjusted the 4 a/f screws to no avail, and I have resync'd the carbs several times. Problem started when I switched to a freer flowing exhaust. Bike idles and rides through the gears fine if you are giving it throttle. As soon as I try to cruise in 4th and 5th at that rpm I get the stutter. Ok enough of the rant. I will work on it again at a later date. I will most likely have another bike before this issue is resolved. LOL!!

When you swap to a free flowing exhaust, you RICHEN up the A/F mixture. What set up are you running? Typically you should go leaner.

 

[Traumahawk]

Got the 2011 out and about and got the exhaust sorted out. Sounds good if I do say so myself.

 

[vince99frc]

When you swap to a free flowing exhaust, you RICHEN up the A/F mixture. What set up are you running? Typically you should go leaner.

So I am going the wrong way? Let me get this straight. Clockwise is the same as righty tighty(closing) so leaning out. Counter clockwise is lefty loosey(opening) so richening? Must be nice to have a Gen 2 as well. That is my goal to, but still stuck on intermittent fixing of the Gen 1.

 

[Devl Max]

Experimenting with a new look, the Vmax Roadster. Added a Daymaker and a new tail light "The Primo" from Ghost Rider Customs. Also had to replace the final drive after a near catastrophic failure in 300 rear wheel assy. No problem, design issues made much better my in repairs. I think the headlight and taillight may signify a possible completion save for some sort of graphics to complete the roadster idea I'm looking for The Vmax Roadster Psyco!View attachment 69487 View attachment 69487 View attachment 69488 View attachment 69489 View attachment 69487 View attachment 69488 View attachment 69489 View attachment 69490

What a beautiful bike!

 

[user 16790]

I adjusted my rear shocks. Took less than 5 minutes. Spent 2 hours trying to get rid of the 4krpm stutter and was unsuccessful. I have done the COPs, adjusted the 4 a/f screws to no avail, and I have resync'd the carbs several times. Problem started when I switched to a freer flowing exhaust. Bike idles and rides through the gears fine if you are giving it throttle. As soon as I try to cruise in 4th and 5th at that rpm I get the stutter. Ok enough of the rant. I will work on it again at a later date. I will most likely have another bike before this issue is resolved. LOL!!

have you tried raising the needles

 

[vince99frc]

have you tried raising the needles

No sir I have not. Not much carb knowledge here. Unfortunately I live in an area full of crooks and I dont have a lot of free time in my life. Hence having an hour here or there a month to tinker.

 

[Traumahawk]

So I am going the wrong way? Let me get this straight. Clockwise is the same as righty tighty(closing) so leaning out. Counter clockwise is lefty loosey(opening) so richening? Must be nice to have a Gen 2 as well. That is my goal to, but still stuck on intermittent fixing of the Gen 1.

Lets talk some carb theory here for a sec. CV carbs....constant velocity carbs....the carbs that are on the Vmax, arent like the carbs on muscle cars and the like. Usually when you put headers or a better exhaust on a car, you MUST richen up the carb......IE go up a couple of jet sizes in the carb...etc.

With CV carbs, when you put on a free flowing exhaust.....a 4-1 and the like, Your making the carb TOO rich. Look at it this way, with more air flowing out of the bike, you will have more air flowing INTO the bike, and with that, the extra air will PULL more fuel into the carb, making you rich EVERYWHERE.

For generalities sake, you are dealing with 3 different fuel circuits in the carbs. The pilot screws.....A/F screws...cover from 0-4000 rpm (roughly) and 0 to 1/8th....maybe 1/4 throttle. From 4000 rpm to roughly 7000 rpm, this area is governed (the mid range) by the needles, and 7000 and above its the main jets (which also control fuel EVERYWHERE), so if you go leaner on the main jets, it will make you leaner EVERYWHERE.

So, when you mention a free flowing exhaust..is it a 4-1..or atleast a 4-2 (a full header and baffle)? The generic recipe is dropping the main jets from the stock 152.5's to 147.5's and putting a shim under the needle (to pull the needle open sooner.....and thus allow more fuel. Remember, by dropping 2 main jet sizes you have leaned it out everywhere, so you have to richen up the midrange...or else you will be too lean, using the stock needles.)

If you just have slip-ons (which arent considered free flowing....because the main restrictive area in the exhaust are the stock head pipes), typically you drop 1 main jet size...because the stock Vmax jetting is just a bit rich from the factory, which even a stock Vmax will typically benefit from as well.

Make sense?

 

[vince99frc]

Lets talk some carb theory here for a sec. CV carbs....constant velocity carbs....the carbs that are on the Vmax, arent like the carbs on muscle cars and the like. Usually when you put headers or a better exhaust on a car, you MUST richen up the carb......IE go up a couple of jet sizes in the carb...etc.

With CV carbs, when you put on a free flowing exhaust.....a 4-1 and the like, Your making the carb TOO rich. Look at it this way, with more air flowing out of the bike, you will have more air flowing INTO the bike, and with that, the extra air will PULL more fuel into the carb, making you rich EVERYWHERE.

For generalities sake, you are dealing with 3 different fuel circuits in the carbs. The pilot screws.....A/F screws...cover from 0-4000 rpm (roughly) and 0 to 1/8th....maybe 1/4 throttle. From 4000 rpm to roughly 7000 rpm, this area is governed (the mid range) by the needles, and 7000 and above its the main jets (which also control fuel EVERYWHERE), so if you go leaner on the main jets, it will make you leaner EVERYWHERE.

So, when you mention a free flowing exhaust..is it a 4-1..or atleast a 4-2 (a full header and baffle)? The generic recipe is dropping the main jets from the stock 152.5's to 147.5's and putting a shim under the needle (to pull the needle open sooner.....and thus allow more fuel. Remember, by dropping 2 main jet sizes you have leaned it out everywhere, so you have to richen up the midrange...or else you will be too lean, using the stock needles.)

If you just have slip-ons (which arent considered free flowing....because the main restrictive area in the exhaust are the stock head pipes), typically you drop 1 main jet size...because the stock Vmax jetting is just a bit rich from the factory, which even a stock Vmax will typically benefit from as well.

Make sense?

Very good explanation and I now have a better understanding of what is going on. The exhaust I have is a replica of the Star Rider Street Flow 4 into 1 exhaust. Looks like below. I do have the full header. Purchased from John Furber and he helped install. Tonight I plan to pull the bike out and lean her out via the air/fuel mixture screws and take her for a ride and see if the symptoms decrease. I would really like to ride the old girl to work in comfort.