Buying my first Vmax.

[naughtyG]

It sounds like you have some air left in your system. It's possible to have a little in the slave cylinder after bleeding. Prolly the best thing is to leave it overnight to let gravity do its job - air bubbles should and will rise up.

Also, when you reverse-bleed, make sure to open the bleed nipple only just enough to allow fluid through, otherwise you'll be pumping air into it! It helps to put a little teflon tape on the thread to keep things sealed.

 

[Saml01]

Update.

Reverse bleeding the clutch definitely helped. I can sit at a light and the bike doesnt want to creep. So thats one down. Probably could be even better but at least now I can get into neutral with ease.

HOWEVER.

I found a very interesting problem with the non firing cylinder.

Firstly, you were right about it not getting spark. When I touched the spark cable I felt the shock through it. So it was probably grounding out on the frame. I ran it through some 5/16 fuel hose to insulate it from the frame and it helped. That cyl got hotter and the bike started easier.

However still not as good as it should be.

I took the filters off all the carbs and examined how they all work. I noticed that in the carb responsible for the problematic cyl, the slide was vibrating up and down very slightly and fuel was being pulled past the needle into the bore. The other carbs just sat dead. If I held the slide closed to prevent it from moving fuel still squirted through the needle jet.

The diaphragm in this carb is good, I checked to make sure there were no blockages in any ports or jets.

I have no idea what could cause that. Float level maybe? I checked it and set it identical to the other carbs when that carb flooded two days ago, and the carb doent overflow either. Vac too high?

 

[The Beekeeper]

Just to make sure you don't have an underlying problem perform a compression check on all 4 cylinders, they should all be within 10 to 20 % of each other. once again make sure you have a strong spark also............

 

[Saml01]

Lets assume compression and spark is fine, what would cause the condition I described.

 

[RaWarrior]

Potentially out-of-sync carbs? If the slide is jiggling at idle (all mine sit dead when idling), there indicates there's too much vacuum in that cylinder, maybe from the throttle shutting too much. That would cause the slide to jiggle and pull fuel out of the needle instead of relying on the pilot circuit like it should, which would make it run rich.

 

[Saml01]

This is carb number 2 btw, the one whose vac is controlled by the throttle stop screw. I dont know how far I should back it out so its not to low where it will stop the jiggle but will affect idle on the rest of the carbs.

Can you give me a ball park how many threads should be exposed in the throttle stop screw?

Also, what tools or gauges do you guys use for carb syncing?
Im thinking of picking up a set of these.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270438398588&ssPageName=STRK:MEWAX:IT

 

[RaWarrior]

The throttle stop screw is something different and does not affect the sync. Adjusting that means the carbs are out of sync at a different RPM. The idle screw should be adjusted so it idles at around 1000 RPM, after I sync'd mine it was idling sightly faster/smoother than before, and turned down the idle screw to compensate.

If you look in between the left two carbs you'll see a small screw for a flat blade screwdriver. That sync's the left two carbs to each other. Between the right two carbs, there's two similar small screws. One syncs the right two carbs together, then the other syncs the left side to the right side.

Those vacuum gauges would work, but not without a flow reducer/damper. A plain gauge hooked up would wildly bounce back and forth with the "pulses" of the engine and be totally useless. You could install ball valves between those gauges and the engine, and adjust the valve(very nearly closed) until the needle has only a very small amount of bounce.

I used dealer tool for Honda outboards that was four dial vacuum gauges on a rack, each with it's own damping valve.

 

[Saml01]

Flow reducer, you mean that tiny little check valve looking thing like on the manifold pressure sensor?

 

[RaWarrior]

In the picture of the gauges I used you can see a small valve underneath each dial, you just adjusted each one until the gauge gave a smooth reading. They are just plain ball valves.

Fluid style gauges typically just have a plug/insert somewhere in the line that only has a very small opening in it to dampen the vacuum pulses.

 

[Saml01]

I picked up those 4 gauges and will try to pickup 4 of these to.
http://www.autozone.com/autozone/ac...&fromString=search&itemIdentifier=369702_0_0_

Wish me luck, should be interesting.

In the mean time, I will adjust the sync screw down and see if it stops the jiggle in that carb. Thanks for the hand holding, you have no idea how much I appreciate it.

 

[RaWarrior]

I suppose an even easier way to dampen the vacuum is to put a small c-clamp on each hose, and adjust the "pinch". Or fold it over and use a zip tie, tighten the kink in the line until they read steady?

It's a pretty specific amount of damping required, a generic "reducer" may not cut the flow enough to eliminate needle bounce. Like I said, the ball valves on my gauges were just barely cracked open.

 

[Saml01]

Thats a pretty sweet idea. I may give it a shot. Ill also take the reducer on the MAP sensor with me so I can compare the size of the hole.

Also found these.
http://podi.ca/Accessories.aspx
Scroll down to anti-buzz restrictor.

I also did some research into home made vac sync gauges and it seems that a certain type of aquarium air pump restrictor commonly sold in pet stores can also work well.

In other news. I came home and examined the butterflies in the carb and the aformentioned carb was noticeably more open than the rest. I backed off the idle set screw to close it, then adjusted the sync screw on 1, 3, and 4 an equal amount to open.

Its not very scientific but at least now hopefully when I start the bike it wont foul out the plug.

 

[Saml01]

I performed a carb sync this evening with a more sophisticated method, this time with a running engine. Engine started and I monitored all the carbs. Number 2 once again was sucking down fuel from the needle jet at idle, the rest were not. I backed off the idle set screw to stop it from doing that. The engine died. I then increased the opening on carbs 1,3 and 4. 1 full turn each until the engine started. After the engine started I noticed 4 was pulling fuel out of its needle jet now. Backed it off until it stopped. I then had the same problem slowly creep to number 1 and after I backed it off, the engine idle on its own with all slides dead.

I would put money on the fact that I don't technically need a sync gauge. I basically have them right under the point where they will start to pull fuel from the needle jet. This is not the optimal place for idle though because the vacuum is too high.

I also have an intermittent spark on number 2 which isnt helping matters and I think thats due to a bad wire. Will replace and diagnose further.

But for the most part the bike runs so much better.

 

[RaWarrior]

If it's running better then it sounds like you got it dialed in at least pretty close. If you ever run into a manometer(know anybody at a shop?) it's worth your time to actually do a sync but not a huge deal. There was a manometer being passed around forum members in the mail for a while, I'm not sure if it's still going around or even who owned it.

Get the plug wire fixed and see if that sorts things out. If you never want to deal with coils cracking or plug wires again, convert to COP(coil on plugs). It's an easy mod, made even easier since a member here is making adapter harnesses now. All you have to do is buy a set of four coil stick on ebay, they go for anywhere from $20-$50, and off pretty much any sportbike will work. Plug the adapters (or cut and splice) into the stock coil connectors, stick the coils on the plugs, and hook them up. Done. With the adapters, it's totally plug and play and probably a 10 minute mod.

Mine are off a 2007 R6. Work great, easier starting, more responsive throttle.

 

[Saml01]

I read the COP thread, its a nice upgrade and certainly one I could handle easily. However, IMHO is unnecessary, at least not until I can see some hard facts comparing spark energy output of the stock coil and cop and dwell for coil and cop. My bet is the people who upgraded had old plug wires and had those been changed it would run the same as COPs.

The thing is, a cop is good if you can use it the way it was designed. Most importantly running it at the correct dwell setting. If it requires more dwell than a coil, then its not getting a full charge. If it requires less dwell, than its being over heat due to extended charging thus breaking down the windings inside, also hurting spark output.

I converted one of my cars from coils to cops and that was a nice upgrade because I got a hotter spark letting me run a larger gap than stock and not have spark blow out under boost. Most importantly however, I was able to half the dwell time for the COPs, giving me a much smoother idle and more consistent spark at higher RPM's due to faster charge times.

In conclusion, COP's are fantastic vs coils but you gotta be able to run them the way they are designed to really reap the benefits.

 

[Saml01]

How does this bike get a trigger signal for the spark? What does it use to sense the crank angle basically.

 

[RaWarrior]

There are trigger coil(s) on the flywheeel. I think earlier bikes had four and later ones only had two, but I could have that backwards.

The Vmax is a "wasted spark" ignition, it fires the plugs every time the cylinder is at TDC minus timing, so it fires on the top of the exhaust stroke also.

While it's difficult to get "hard facts" on COPs, benefits are pretty widely reported. I ran them for around 6k miles this summer with zero issues, a lot of people here have run them for much much longer. It has been noted that the Dyna ignition will fry if used with COPs though, while I have not heard of any issues with the stock ignitor. When I replaced mine, the p/o had replaced the stock coils with Nology "pro fire" coils and brand new NGK wires. I replaced them based on Nology's generally shitty reputation, and as part of chasing a misfire (that turned out to be a fuel issue). Instantly noticeable improvement.

 

[tugla]

There are trigger coil(s) on the flywheeel. I think earlier bikes had four and later ones only had two, but I could have that backwards.

The Vmax is a "wasted spark" ignition, it fires the plugs every time the cylinder is at TDC minus timing, so it fires on the top of the exhaust stroke also.

While it's difficult to get "hard facts" on COPs, benefits are pretty widely reported. I ran them for around 6k miles this summer with zero issues, a lot of people here have run them for much much longer. It has been noted that the Dyna ignition will fry if used with COPs though, while I have not heard of any issues with the stock ignitor. When I replaced mine, the p/o had replaced the stock coils with Nology "pro fire" coils and brand new NGK wires. I replaced them based on Nology's generally shitty reputation, and as part of chasing a misfire (that turned out to be a fuel issue). Instantly noticeable improvement.

i thought your fuel issue was fixed with the COP not the carb setting, maybe i have to go back and re read it.

 

[Saml01]

Quick question guys. Kinda worried.

My bike is in the garage, I went out to check some stuff and felt up the fuel lines. The ones I changed on the carbs and off the pump are harder than a rabbits dick in the frozen tundra. Its not even that cold in my garage.

I noticed this last time and after the bike ran and warmed up they became pliable once more, so I thought it had to be the fuel pressure. However, they shouldnt be stiff as a rock because this time the bowls were drained.

Is this normal?

This is regular old rubber hose that autozone stocked.

 

[RaWarrior]

i thought your fuel issue was fixed with the COP not the carb setting, maybe i have to go back and re read it.

It was kind of nebulous, but I think adjusting my needles finally solved it. I may not have updated my thread about that. The COPs definitely helped though.

It was sort of tough to track since sometimes the problem wouldn't appear for days or weeks, so you could never be sure making a change actually solved it, or if the problem just wasn't "acting up". It may have seemed like COPs fixed it, but a couple weeks later the misfire appeared again. After talking with Sean and Dynojet(they actually have pretty decent customer service, and all but admitted their stage 1 has tuning issues)

"harder than a rabbits dick in the frozen tundra"
I think the technical term is harder than a priest at a playground, but I think I get your drift. :eusa_dance:
If the lines are new, I wouldn't worry too much about it. Is it the fuel line that's smooth and shiny, or the more flat, rubbery kind? The shiny kind tends to get pretty stiff when it gets cool.