1st Gen V-Max The adventure begins

[Fire-medic]

Ok, Maiden voyage and first ever ride on a V-max. First impression: I love this bike!.... It certainly is no torque monster but then I've been riding a 2053cc V-Twin for the last 4 months so I may a bit jaded. She's got every bit of the 98HP/86Lb-Ft claimed. Very docile and good manners low down in the RPMs, things get interesting in 4th around 4500 RPM and then surge at 6000 just like everyone says. I ran out of room at 130 Mph. Suspension is pretty stiff and bone rattling but stable. All reports suggest this girl is not a corner taker but I beg to differ, very stable in the lean but I do believe some suspension work could sort this into a sweet canyon carver (not a knee dragger). She is worth putting in some more time and money - Fun! So for now the V65 gets her turn in the bay, valve adjust, oil mod kit, bar change and general maintenance

I forget, do you have a 'neutered' U.K. version of the VMax? Your HP claimed is much-lower than the USA market version/model, even when taking into-account a dyno BHP rating, which is usually around 110 RWHP. Oh, I know, you're running Cobra four-into-four exhausts! A minor peccadillo to be sure.

Retrospective: Yamaha VMX12 V-Max 1200: 1985-1986 (also 1988-2007) | Rider Magazine | Rider Magazine

 

[RadiumPHX]

I forget, do you have a 'neutered' U.K. version of the VMax? Your HP claimed is much-lower than the USA market version/model, even when taking into-account a dyno BHP rating, which is usually around 110 RWHP. Oh, I know, you're running Cobra four-into-four exhausts! A minor peccadillo to be sure.

Retrospective: Yamaha VMX12 V-Max 1200: 1985-1986 (also 1988-2007) | Rider Magazine | Rider Magazine

No its a US / non-ca model with stock exhaust. I've seen all sorts of numbers for the 1st gen, 145HP at the Crank 98 to 110 at the wheel, I don't know what to believe without a real dyno sheet. She "feels" like a wee bit more than my V65, particularly in the upper RPMs but not much. I don't pay too much attention to the HP/TQ numbers game but I do know what 100HP on two wheels feels like

 

[Fire-medic]

I recall the V65 being released, the Suzuki GS1100/1150 E and ES and the GPZ1100 and 750 Turbo, they were all pretty-close in stock performance. The VMax then became king of the hill. As the new water-cooled liter-class sportbikes were released (or the air/oil-cooled GSXR750 and 1100 Suzukis) the VMax got more competition, and was beat on aerodynamics. Then-again, I've never been one to use my VMax for wott'le she-do, on top-end, mister?" status. The VMax is easier to launch than a short-wheelbase liter sportbike with beaucoup horsepower.

However many HP there is, they are very-entertaining horses!

 

[RadiumPHX]

Well, back square one. I disassembled the carbs and fully cleaned all jets, jet block the whole deal which did make a significant improvement. But... this thing is a turd below 5000 RPM. Many have said this bike will let loose the rear tire in 1st, 2nd N' 3rd but this girl just doesn't sound right and aint got much in the lower end. Even at rolling 30mph, bump the RPMs up to 7K and dump the clutch nothing much really happens. So.. compression check, coil check, look at the plugs (new, 50 miles on em).

Starts easy, with choke, settles into 1050 idle with no choke in about a minute.
A/F screws all at 2.5 turns. When adjusting the A/F cylinder 2 will not stumble with screw all the way in. 1, 3, and 4 will. None of the A/F screws will hit peak and then drop idle again as you turn them out.
Still an occasional "chuff" out the intake, is this common?
Running fresh 92 octane
All cylinders running at same temp.
Once past 5K RPM she "seems" to run as she should (I have no reference at this point). Will do 135MPH.

So my question to all the VMax veterans here: the A/F is for idle and just off idle, will a blockage affect low/mid power significantly? I have resigned to getting a full rebuild kit and carb teardown again, no big deal. Just trying to identify if I have multiple issues, more than carbs.
Am I expecting too much from a Gen1?

 

[02GF74]

You don't say if you balanced the carbs after cleaning.
Also check fuel filter or just replace it. The tank is notorious for rusting.

 

[RadiumPHX]

You don't say if you balanced the carbs after cleaning.
Also check fuel filter or just replace it. The tank is notorious for rusting.

I have not synced the carbs or checked em, I do have a set of gauges. The tank is clean and fuel pump is pushing clean fuel. I'll swap in a new filter.
Just got a laser thermometer, gonna check temp on header pipes as well.

 

[Fire-medic]

Something is definitely the matter. The bike should break the rear wheel loose easily in the lower gears, especially if you're cornering, and you grab a handful of throttle (not recommended!) so there's something going-on. Synching is definitely important to get an even idle which holds at a set rpm, which doesn't vary, and for good throttle response. That one cyl which has no adjustment having results tells me you probably have a blocked passage in the body.

Be sure to check the directions for the IR gun, mine has a wide cone of area of sensing, you have to hold it pretty-close to the subject to get the reading for that piece of tubing (an exhaust header).

Have you seen the mechanism for the VBoost is cycling when you turn-on the ignition? The butterflies should open/close when you turn-on the ignition, before the bike is started.

You should be able to get a rolling burnout at 30 mph and dropping the clutch @ 7K rpm.

 

[RadiumPHX]

Something is definitely the matter. The bike should break the rear wheel loose easily in the lower gears, especially if you're cornering, and you grab a handful of throttle (not recommended!) so there's something going-on. Synching is definitely important to get an even idle which holds at a set rpm, which doesn't vary, and for good throttle response. That one cyl which has no adjustment having results tells me you probably have a blocked passage in the body.

Be sure to check the directions for the IR gun, mine has a wide cone of area of sensing, you have to hold it pretty-close to the subject to get the reading for that piece of tubing (an exhaust header).

Have you seen the mechanism for the VBoost is cycling when you turn-on the ignition? The butterflies should open/close when you turn-on the ignition, before the bike is started.

You should be able to get a rolling burnout at 30 mph and dropping the clutch @ 7K rpm.

Thank you Fire-medic, this was the feedback I was hoping for. My IR gun has a 1.5" cone at 11 inches. The V-boost servo is working correctly, cycling during power/key on and I checked the butterflies when doing the carb clean, they open/close as expected. I have viewed many YT videos try to get a sense of the VMax engine character and exhaust note. My bike seems to lack the classic V4 lope at idle and sounds/feels more like a lawnmower, as if it is running on only 2 cylinders yet I get even cylinder and exhaust temps (by feel). So, back to basics verifying fuel, spark and compression values (suck, bang, blow).

 

[Parminio]

I have not synced the carbs or checked em

That's your problem.

 

[RadiumPHX]

Did a exhaust header temp reading. I have no reference for what "should be" but here is what I got. Now I verified the IR gun with boiling water and it was right on at 208 F at 3000 ft elev. Rode the bike for 20 miles, parked it for 20 minutes, then started it up a let it idle for a good 15 minutes until the Rad fan was kicking on.
Ambient was 78F, Wind dead calm
temp values: C1=197F, C2=107F, C3=230F, C4=123F
C1/C2 Exhaust tip 109F C3/C4 Exhaust tip 103F
I then raised the idle to 3K for 30 seconds while measuring C4 (front right) and it consistently climbed to 150F, Did the same on C2 (front left) and it slowly raised to 111F
So, it seems to me to be wildly different and the front cylinders cold in comparison. I would expect the rears to be somewhat higher by 10/20 degrees, even 30.
Next up Compression test, do you guys pull the coil low volt sides or just leave the run switch off?
added: Compression is 180 (+/- 2) across all cylinders. plugs say 3/4 running a bit lean.

 

[Fire-medic]

It's fairly easy to disconnect the connectors to the ignition coils, so they're not getting any signal. I don't know that it's necessary, but I might disconnect the fuel pump too.

That's interesting that the LR and the RF cyl's are not warming-up, that suggests to me that you don't have ignition occurring reliably in those cyl's at idle. I expect that would be due to blockage/obstruction, especially if the midrange and upper-end rpm's are doing OK.

I think you would have a really crummy-running bike across the rev band if you had a poor valve seal on the intakes and/or exhaust valves. I believe on the intake side, the engine would be continually be 'popping' through the carbs, it would idle erratically, throttle response would be in the toilet, and it would exhibit a much-reduced power output. On the exhaust side, you might get backfiring through the exhaust, maybe flames, as the mixture exited the ignition chamber/cyl head, and then the fuel/air mix ignites down the exhaust headers.

 

[RadiumPHX]

Update: As I was preparing to re-clean and install a carb rebuild kit, I drained each bowl into a cup and found multiple bits of black rubber I will guess to be from the fuel pump which negated any progress made from cleaning the carbs and somewhat explains the erratic behavior (the bike, my erratic behavior is not explainable . So, I will looking for a new pump or rebuild parts for the old one and repeating the entire clean process.

 

[VMAXXIMUM]

Black rubber bits seem more likely to come from old fuel lines than your fuel pump.

 

[Parminio]

Black rubber bits seem more likely to come from old fuel lines than your fuel pump.

True, that. But on an '07? Unless somebody at some point ran some sort of overly aggressive fuel system cleaner through it, how on earth are the fuel lines already falling apart?

Cheap rebuild kit O-rings maybe?

 

[RadiumPHX]

This bike sat still in a garage since 2010, remarkably the fuel tank is near factory clean. I just pulled the fuel pump apart and there is no sign of a degraded diaphragm nor bits of black rubber, re-assembled pump. I am installing a new fuel line with a filter between the pump and carbs. checked rear coils as well, both are at 2.8 ohms. I did find the carb bowl drain screws weeping fuel and cracked o-rings (replaced o-rings) which may explain the black rubber bits in the drain lines. I am gonna run a few bowls of fuel and check for contamination.

 

[RadiumPHX]

Update: minor improvement in lower end and a rocket past 4500 rpm. Still does not let loose the rear not matter what gear or how the throttle is applied easy roll, fast to mid throttle, I can be exiting a corner and go WOT in 2nd, 3rd or 4th and it just isn't the dangerous bike I was hoping for, does pick up the front end a bit. It will burnout holding the front brake and wind her up. I'm a bit at a loss at this point. My expectations are similar performance to my 96 ZX11 which will indeed let loose the rear and pull the front wheel up with very little effort, this bike off the corner/line is just a pig. I guess it may be time for a dyno or maybe the VMax just doesn't have it to begin with. I need to find another VMax to compare and see if my expectations are out of line.

Compression check: 180 +/- 2 all 4 cylinders
Carb sync all even (see video)
A/F screws all at 2.5 turns
plugs set at .032 in
92 Octane fresh fuel
Coils primary all at 2.8 ohms
header temps all at 240F +/- 5 deg
exhaust temps 114F both sides
cold starts with 3/4 choke
hot starts no choke, no throttle, no issues
reaches mid temp and stays there all day
Completely factory OEM.

 

[Fire-medic]

On a Dynojet 250 dyno, you should expect to see a # around 110 RWHP.

 

[RadiumPHX]

On a Dynojet 250 dyno, you should expect to see a # around 110 RWHP.

Do you have a reference dyno sheet? im looking for the RPM/power curve. She seems to have plenty of power past 4500/rolling on from 40mph, just not much from idle to 4500.

 

[Fire-medic]

(53) Totally bummed out | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net) Post #6

(54) Video of the "Cruise Missle" on the DYNO | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

(54) Topeka Dyno Day | Page 3 | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

(54) First Dyno run with the Turbo Vmax | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

(54) finaly put it on a Dyno, not good | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

(54) Dyno at AJ's Racing on the PCW 1500 | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

(54) True Horsepwer? | Page 3 | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net) Lots of interesting results and info on use of dynamometers, and the VMax

This should keep you busy awhile.

 

[RadiumPHX]

Update:
Rain in the forecast so the max is inside. Finally got a decent compression tester and got the following results (opinions welcome).
9/18/21 Vmax 1200 Compression results
cyl 1 dry 155 wet 165
cyl 2 dry 150 wet 165
cyl 3 dry 152 wet 165
cyl 4 dry 160 wet 170

50 miles on plugs
Plugs 1, 3, 4, are off white ashy, slight browning on insulator. Plug 2 is cleaner?
I am thinking 1,3,4, are running too lean.
Checked spark with plugs on all 4 cyl, is good.

Got the carb rebuild kit and fork seals in, carb time.