One cylinder running Rich

[James t]

Hello everyone I'm new to the forum but I've been around a while, I've got a 1985 VMAX with 4800 miles that's right 4800, it runs great idles fantastic all stock jetting stock exhaust carburetors are very clean but I have one cylinder running rich and I took the slides out and I noticed that there's a little washer besides the white one underneath all the slides to richen it up a little my question is did it come from the factory with any washers under the needle or did it just come with the little white one, do these bikes like to run a little lean or a little rich I'm also getting a popping from the exhaust at high RPM at deceleration thanks

 

[Parminio]

I'm also getting a popping from the exhaust at high RPM at deceleration thanks

A lot can cause that. The air cutoff valve being stuck or bad is one reason. Check that out.

You also need to check for vacuum leaks, especially on a bike that old. Take some carb cleaner, or WD 40 and shoot around the boots where the carbs connect to the manifold. If you get idle changes, you've got leaks and the boots need to be changed.

 

[James t]

Ok I'll check the valve ,but the boots look brand new no visible cracks ,this was my brother's bike and it sat in his shop for years he passed away from f****** cancer a few months ago , btw the air cutoff valve is on the side correct? I just bought some new boots they are pretty cheap that way I can eliminate that, thanks

 

[Fire-medic]

A lot can cause that. The air cutoff valve being stuck or bad is one reason. Check that out.

You also need to check for vacuum leaks, especially on a bike that old. Take some carb cleaner, or WD 40 and shoot around the boots where the carbs connect to the manifold. If you get idle changes, you've got leaks and the boots need to be changed.

The VBoost to cyl heads junctions need to be also leak-checked, and if you find one is bad, replace all four of the O-rings because removing the manifold will probably cause the others to begin to leak, if you try to 'cheap-out,' and just replace the one you found bad.

I'll let dannymax answer the 'extra washers under the slide needle' as an OEM issue. Bikes are often set rich from the factory, as there's less chance of hurting an engine running it rich than running it lean. You probably have 152.5 main jets, and many people find that going down one or two sizes (150 or 147.5 Mikuni) helps the bike run better.



Here are some things for you.

VMX12- Service-Manual.pdf (vmoa.net) Save it on your computer and print it out and put it into a 3 ring binder for shop use. yearly model updates are found in the front, as supplements. The appendix in the back has bolt/screw sizes, torque values, cable and hose routing, and more.

(66) New Vmax Owner FAQs....new members please read! | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)
This answers many questions you may have.

1985 Yamaha V MAX 1200 (VMX12N) OEM Parts, Ron Ayers One of the Yamaha dealers parts fiche locations, another one to save as a 'favorites' on the computer.

Sean Morley [email protected] Sean sells new and used parts, he modifies bikes, and he sells his modified bikes and parts. He is also on facebook, Morley's Muscle is the business he operates. He freely advises people on the site about how to obtain parts and how to fix things. He's probably the #1 resource for ailing bikes having problems. He's in Kansas, but is as-close as UPS, USPS, or FedEx.

CaptainKyle [email protected] is another great resource for new and used parts, repairs and advice. Another UPS, USPS, or FedEx close-by person.

dannymax specializes in carburetor work and rebuilds. He runs each rebuilt set on a testbench and provides you with a video. Another UPS, USPS, or FedEx close-by person. Look him up under 'members' at the top of the page.

 

[James t]

On the one cylinder running rich I did take the washer out underneath the needle and now that cylinder is not running rich anymore plug is nice white and tan, right now I'm running with just a white washer with a little tit on it underneath the needle and the spring clip I'm not sure if that was OEM or not I've heard that factory is just the spring clip I'll post some pictures later thanks for the reply guys, the bike also came with the stage 7 kit with all new slides jetting and some kind of hose that goes on the oil fill cap I'm not going to put it on stock is good enough for me plus I want to keep the bike all original I'll never sell it being that it was my brother's, I didn't notice any power difference taking the washer out from the needle I agree though running it a little rich probably is better than running it a little lean but most of the popping went away from the exhaust running it on just a white washer with the tit on it, like I said I would just like to know what was factory and then I'll go from there

 

[DreamV4]

Popping is sign of lean mix, you can have 2 problems, well, considering age of bike, it probably has 102 problems (like my bikes)

 

[James t]

I thought popping was a sign of running rich on burnt fuel hitting the exhaust

 

[DreamV4]

I thought popping was a sign of running rich on burnt fuel hitting the exhaust

Lots of bikes have air injection system, pumping air into exhaust to get exhaust gas burnt better. Common fix for popping is to disable the system. I don't know if Vmax has this system, ask Sean or Firemedic, they know everything.

 

[James t]

Is this a stock setup or is this a stage one kit I've heard different stories I think the needle size is a 243

 

[James t]

Anyway here's the bike 85 all original it still has the original tires which I don't think is a good thing

 

[James t]

Also can somebody tell me what stage kit this is, also can somebody post pictures of how the center stand goes on I do not see any brackets at all where it connects to, it did not have a center stand when I got the bike but I bought one off eBay with the spring

 

[V4max]

Nice bike man!!! As far as center stand I have no idea I have the kerker exhaust so mine is eliminated. I'm sure someone will chime in and fill you in on whatever questions you have.

 

[dannymax]

Also can somebody tell me what stage kit this is, also can somebody post pictures of how the center stand goes on I do not see any brackets at all where it connects to, it did not have a center stand when I got the bike but I bought one off eBay with the springView attachment 83896View attachment 83897View attachment 83897View attachment 83898

Stage 7

 

[dannymax]

Is this a stock setup or is this a stage one kit I've heard different stories I think the needle size is a 243View attachment 83881

Stock

 

[James t]

 

[James t]

It looks like these other slides are already drilled out larger so if I put the new slides in with the stage 7 needles and springs what will that do for me without re jetting the carb

 

[James t]

This afternoon I'll put in the slides springs and needles right now it appears they're on the 3rd notch down from the top, if I don't see any kind of power difference with just the slides springs and needles I'll just go back to stock that's good enough for me besides I am in no hurry for them to scrape me off the pavement

 

[one2dmax]

If it had a Kerker header previously installed then the frame tabs to mount the centerstand with is going to have been removed.

 

[James t]

Okay I don't think I had a header on it since it was my brothers and he never drove it, I heard a rumor that some bikes in 85 didn't come with a center stand maybe I'm wrong

 

[Fire-medic]

No not bikes w/o centerstands from the factory that I've heard of.

With the four mounting tabs for the center stand, one needs to be totally removed and the other one on the same side can be heated and bent to provide necessary clearance. In that fashion you have one less tab to reweld should you decide to return it to stock.