Advice on Carbs

[grimmie]

I have my 2000 Vmax that I bought about 2-1/2 yrs ago. I put the Holeshot exhaust on it and I bought Dale Walkers stage 1 kit when I purchased the exhaust. I never put the stage 1 kit in. Lazy, not enough time, {insert excuss here}. Ha ha

It does run rich but pretty much runs great. It has right at 16000 miles on it. When I bought it the carbs had just been synced. Not sure about cleaning. I regularly run Sea Foam through it. I haven't had any issues with it, and still don't really have any major issues.

It starts and idles fine. With the motor at normal operating temp it has started to stumble just a little off idle, nothing really bad. Just in the last couple of weeks it sounds like it has started to drop a cylinder while running along at about 4500 rpm. Once I hear it drop, I can just ever so lightly touch the throttle and the cylinder comes back. It does this a handful of times a day.

I just purchased a Motion Pro SyncPro that will be here this week. I have never had the carbs synced myself, and I know they should be synced fairly often.

I know I should at least do the Shotgun and/or the Pea shooter methods. I need to install the stage 1 kit as well.

Should I do a full tear-down/rebuild on the carbs, or do you think the Shotgun will take care of things?

Also should I go ahead and install the stage 1 kit while the carbs are down, or should I do the rebuild/shotgun and make sure everything is good to go before introducing the stage 1 kit? I know that sometimes it's better to do one thing at a time.

If the rebuild is the way to go, is there a kit I need to get or should I wait a see how the carbs are first?

I changed the fuel filter (Mr Gasket), plug wires, and plugs about 5000 miles ago. I have a new fuel filter and plugs that I'll change when I do the carbs.

I will probably do the carbs early next week. I don't want it to start running bad before I do something about it.

Thanks, Shane

 

[SpecOps13]

Wow, You really need a Sean Morley Input to these questions.

Good Luck,

 

[grimmie]

Well, I spoke with Sean yesterday and got some advice. I ended up running the Shotgun method on my carbs.

I synced the carbs before breaking them down just to see where I was at. Carbs 1, 2, & 4 were close. Carb #3 was about 25% off. As soon as I synced them the idle cleaned up really nice, not that it was idling bad but it was really smooth once synced.

I ran the shotgun and cleaned everything up, and re-synced the carbs.

Carbs were not in to bad of shape. They were getting a little sticky, as there was almost a black oily coating on everything. A/F screw tip was a little sticky.

Thanks Sean for your time and advice. Time to get some suspension upgrades now!

 

[dannymax]

Well, I spoke with Sean yesterday and got some advice. I ended up running the Shotgun method on my carbs.

I synced the carbs before breaking them down just to see where I was at. Carbs 1, 2, & 4 were close. Carb #3 was about 25% off. As soon as I synced them the idle cleaned up really nice, not that it was idling bad but it was really smooth once synced.

I ran the shotgun and cleaned everything up, and re-synced the carbs.

Carbs were not in to bad of shape. They were getting a little sticky, as there was almost a black oily coating on everything. A/F screw tip was a little sticky.

Thanks Sean for your time and advice. Time to get some suspension upgrades now!

Do you have plastic caps over the A/F screw holes to keep water out?

 

[RaWarrior]

From chasing a similar issue myself for quite a while....I think I can give you at least a little help here.

The Vmax tends to run rich in the midrange....just how it is. A slight stumble or hesitation right around 4500 RPM(I had this exact same issue) was from it running too rich and "loading up" under constant throttle. I talked with both Dynojet and Sean about this, and the fact that opening the v-boost instantly clears the problem supports the too-rich theory.

The Stage 1 kit (designed to stuff more fuel in to pair with a high flow exhaust and filter) makes this rich midrange even worse by using a much smaller PAJ2 than stock...stock is a 170, the kit is a DJ150, but DJ sizes their jets differently and it's closer to a 142 or so standard. The main is also larger than stock, and the needle is skinnier also. So almost 30 thou smaller....that's a big difference. This jet along with the needle control the midrange...jet lets in air, needle lets in fuel. There's loads of other factors, but when you want to target midrange adjustments that's the place to start.

The a/f screws have an effect in the low-to-mid range...up to 4500-5000 RPM or so. Beyond that and the flow through the carbs is high enough that the small amount of fuel they meter in for idle/low speed is pretty insignificant.

 

[jfeagins]

Ra, he states he is having problems "off idle" and when warmed up, and that it only began doing this in the past "couple weeks". I think he's trying to fix that problem and not necessarily fix a mid-range one.

That said, it sounds to me as if, perhaps, with the symptoms he describes, that the bike may be having electrical problems - the kind that go hand in hand with low charging and/or low battery voltage problems. If it's only cutting out/dropping a cylinder in the idle rpm range, then clearing up as soon as the engine revs, .........could be the same thing my Max had, and was causing errant spark to jump around @ below 2000rpms and dying at idle occasionally. I cured mine by improving the charging system and putting the bigger battery mod in. We all know the CDI hates low voltages as it gets older and crankier, and will begin doin weird stuff.

This sounds perzactly like my bike did when first I had this problem. It progressed until it did it EVERY time out of the garage and I had no problem spotting spark where it didn't belong.

-just sayin'. Maybe worth checking it out and a look see.

 

[grimmie]

Like said I did the Shotgun method and that cleared up all my issues. The bike runs really well. I put about 60 miles on it today, combo of highway driving and secondary roads. Runs great all the way around. I started it this afternoon and choked it about 1/3 of the way and let it idle for about a minute. Cut the choke off and was able to rev it (lightly of course) without stumbling or popping. Once it warmed up and the temp gauge started to move it ran really good. Starting from a stopped position is a breeze. It doesn't stumble or hesitate at all. Mid-range power is really good. Cruising speeds are fine, and on up to WOT. I'm really pleased.

I'm gonna install one of Sean's kits this winter along with suspension upgrades and radials. I'll need a rear rim too for the radials. We only have about 3 months or really cold weather here and that will give me plenty of time to do everything.

The mod monkey's been following me around for a while now!!

 

[SpecOps13]

Congrats on the fix......:biglaugh:
Most seem to run like crap until warm...... Mine pops, backfires
and bitches till it's warm, then it runs fine.

 

[grimmie]

Thought I would update on where I am right now.

Mod Monkey got me last week. I ordered a Kerker w/2.5 comp baffle, Progressive lowering front spings, Superbike Handlebars, and the Muscle carb kit.

I installed the carb kit and Sean got it tuned thru e-mail. It only took a couple of tweeks.

This thing i like a rocket. Cuts the oil light on in 4th gear now. Awesome kit. I really didn't think you'd be able to feel the difference. Maybe see it on a time slip or dyno. You can definitely feel the difference. Runs great all the way around.

Still running my Holeshot exhaust right now. Sean said the Kerker's are on back order and he will send me one when they come in.

Props to Sean on being available after the sell as well. Awesome guy!! Awesome carb kit!!

 

[Vmaxattacks]

Whadda gonna do wit the Holeshot ?
Congrats on the new (old) ride!:eusa_dance:

 

[grimmie]

Whadda gonna do wit the Holeshot ?
Congrats on the new (old) ride!:eusa_dance:

I'm sure I'm gonna make someone a happy camper when I sell it!!:biglaugh:

 

[Vmaxattacks]

Is it a 4-2 or a 4-1 setup?
Thanx,
Bud

 

[grimmie]

4-2

 

[Vmaxattacks]

Lemme know when you decide to