Another weird one... suction at three outta four carbs...

[James Massie]

Ok, so again not new to Maxes...new to working on them. I decided to finally "get to know" my 1999 Max. Other than an oil change, upgraded stator, tire changes, taillight...

I synced the carbs then pulled the airbox to see what was done to them if anything...
I'm a little weird so I placed my palm over each carb and felt a good amount of "suction" on front left/right left and front right (forgive me for only knowing one of the four cylinder numbers) BUT the right rear cylinder had very little suction." The other carbs pulled my palm down hard and left it covered in a mist of fuel.

I checked the plugs and only that plug appeared to be tight... last owner.... really???

SO.... compression test... what appears to be all good.... 175-180 all four cylinders

Put the new plugs in tight this time....synced the carbs again and no change...

It runs great (knock on wood). There was a light puff/pop sound from what I think was the left rear carb prior to syncing and now they are all running clean.... lower idle mixture and noticeably less carbon/unburned fuel smell. (Hopefully I'll get more than 125 miles tank now)

FINALLY....MY QUESTION
Has anyone every tried the "palm" method? Results? Problems? etc?

Just curious.... does the "palm vacuum check" method fall into the "seat of your pants jetting check" troubleshooting methodology?

 

[James Massie]

Could it have anything to do with vboost? It happens at all throttle openings but i didnt rev it high enough to open the vboost. And wouldn't it happen to all cylinders?

 

[Fire-medic]

Sorry, but if you enjoy riding it so the red light comes-on, on the instrument pod, your mileage before hitting reserve is likely to be < 100 miles. Your mileage may vary, but that is about what I get, on a stock engine with bolt-ons (UFO full exhaust but a custom canister) Dynojet Stage 7, K&N replacement air filter, DYNA CDI ignition.

To ID the cylinders, draw a capital letter N starting w/the right rear cylinder. 1-2-3-4. So the right rear is #3.

I suspect you may have a plugged low-speed carb fuel path. The pilot jet on the carbs is notorious for becoming plugged. It's a tiny orifice. Do a search for 'pilot jet' and you will find info. I suspect you haven't removed the carburetor rack, and then the float bowls? The cleanliness of the carbs (internally), synching, and the float level all have a lot to do in proper bike carburetion.

https://www.vmaxforum.net/threads/new-member-looking-for-any-info-i-can-gather.52866/#post-530792
"palm vacuum check" method: that reminds me of clearing a piece of sand grit from an off-road 2-stroke, when I was riding my 360 Yamaha a lot, in the early 1970's. For some arcane reason, that would often work to clear a sand particle from between the center and side electrodes. Of course after doing that, you had to "synch the carbs" Time to rinse and oil the air cleaner!

No need to hit VBoost while stationary, you want to avoid over-revving the bike. The best mod for a Gen. 1 to promote long life is to install a DYNA or Ignitech ignition box, and to set the redline function on the rev-limiter.

Have you pulled the CV cap on the side of the bike? Maybe #3 has a torn or misaligned CV rubber diaphragm. In used bikes, I've found loose carb brass no-longer screwed-in where it's supposed to be, loose slide needles, a folded-over CV diaphragm no-longer with its edge in the carb body channel, missing rubber plugs for the jet block, etc.

 

[James Massie]

Yeah that little red light needs some tape or something...hahaha amazing I get 35+/- mpg at 90mph....

Hmmmm.... N...got it!!

I did road race 250cc Two Strokes for a few years....maybe that's where I got it lol... NSR250, RGV250, TZR250....

The bike runs/idles like a champ.

I solved the puff/pop with the syncing but I did not pull the set. I did pull the #3 carb cover, inspect the diaphragm for wear/damage/etc and didn't see anything out of the ordinary. It did look a little worn/flatish. I'll prolly order new diaphragms/slides. I think K&L has 'em. I actually worked for them a few years back... but didn't really like their quality on carb parts though. I doubt Mr. Lee is still running the place.

I'll keep checking. I did pull one jet off the top of the carb and saw sunlight...also blew B12 through it... blew B12 through the jet under the diaphragm and it came out the other jet on top.

Jet block plugs? the little rubber plugs that someone used to cover the AF mixture screws?

I'm not sure I'll remove the carbs until I do the valve adjustment. I love riding and less working on 'em now. I live up in the country now.... flies and yellow jackets always buzzing around and no where but a dirt driveway to lay my parts on....

Thanks
James

 

[Fire-medic]

Jet block plugs? the little rubber plugs that someone used to cover the AF mixture screws?

Look at my link I posted, if you haven't yet. The jet block is ID'ed and the particular jets each side has. The rubber plugs are stuffed into the jet block holes where the brass jets are. They rest against the side of the carburetor body. Look above the end of the jet block, and you can see the black plugs, above the yellow and red bars. The main jet blocks most of the yellow one, from view. Part # 43 & 45 are the rubber jet block caps.




The 'pilot set screw' is #22 and the aluminum press-in cap is #54. It's right below the CV side cap covering the diaphragm. If you get a bike w/o those press-in aluminum caps removed, you probably have a bike no one's messed-with yet. Of course, inspection of the innards is always the way to confirm/deny.



https://www.ronayers.com/oemparts/a/yam/50045c0ef8700209bc7942f3/carburetor
Where are you? It's a good idea to give/add your location so people know where you are/what part of the country. Using the signature line to ID what year your bike is, and what mods you have, helps if you have a question about your bike.

Well since you're used to rapid directional changes with 250cc two-strokes, you can give us a report comparison between those and our paragon of fluidity in motion, the VMax.

The shop I frequent is rebuilding a RGV250 streetbike, its motor is spread-out right now like a slow chicken trying to cross a busy interstate.

 

[James Massie]

Thank you FM...Looks like I need to figure some shi(p) out...
Updated my signature...Not sure I did it right...this is actually first forum posting in.... Morgan Hill, CA....no mods that I know of....YET.... muwahhahahaha
WOW...Long way from 38mm Mikunis or Keihins... in the 250s

I love the Max...but my experience on the 250s was knee down at the track...or ass up in the air.....
RGVs Can Fly


They turn like nobody's business and I could easily cut/slide under 600s in the corners... Thank you Doug Polen (yes the real Doug Polen)

for pulling my sorry butt around Buttonwillow faster than I thought I could...sorry not sorry to the dumb a$$ AMA guy on a 600 who thought he could corner faster than a full Sugaya race kitted 1996 RGV250SP with me on it.... he finally got me on the front straight... lol but if I had not been so excited about my lap times and known he was back there I would have given him a run for is money....Can you say "real ram air kit" ten times real fast? I mean... real...pull your arms off at about 100mph and eating poor little 600s up for lunch...SMILES!!!!!


STRAIGHT OUTTA BATTLE FACTORY JAPAN!

I do like a bit of the twisties and spanking sportbikes on the Max... some old school guys have come up grinning and told me they "always wanted one' or "holy shit I had one" from time to time....then there was the spunky little guys like the Ducati Paginale 801 rider that looked somewhat frustrated after beating him four lights in a row... SMILES!!! Youngsters have NO idea what they are in for when they pull up and rev at me....I LOVE IT.... my 85 was even faster...OMFG... Full pipe and jet kit... I miss that one....




Miss my ZRX1200 too.. .sigh... another spanker... yes that's a working police siren...

And my RF900 WAAAAAHHHHHH...two up beating my friend on his CBR1000F across a very windy San Mateo Bridge... hahahaha


OUTTA GAS!!! Thank you to the rider who saw me from the other side of the freeway and swung around and took the time to bring me gas!!!
Never leave home with out a spare bottle again...


TZR250SP with YFZ450 motor!!!!


Don't ride it unless you can build it...


If it doesn't blow up... you aren't riding it like it was meant to be.... thank God for crate motors on eBay!!!

 

[Fire-medic]

That last pic, a GPZ550? Fun bikes, I had a 550LTD, a 750LTD, and a 1000LTD, all bought used. I had a few other Kawis too, they made a good transverse-4 air-cooled bike. I had a couple of the smaller Kawi twins too, bought for next-to nothing, needing fixing, and then sold.
https://www.cycleworld.com/story/bikes/kawasaki-gpz550-launched-the-middleweight-revolution/
Those two-strokes on a tight track, w/a good rider, probably cannot be beat by a bigger bike with your average 'I wanna do a track day!' guy flogging it, thinking he's 'going fast!'

The shop looks like a clean environment. The dyno is a great tool to earn knowledge quickly. The garage w/the black bike under the OH door is your place?

Did the CHIPs ever hassle you about the siren? That would be an equipment violation here in Florida.

I had a BMW R100 RT Airhead twin, I had it painted in pearl white for the fender and tank, and the wide fairing was candy apple red metallic. It had the wide R100 RT windscreen on it so it resembled a police bike. I realized what use that was when I was behind someone on the expressway, I'd see their eyes in the rearview-mirror look at me, and they would slow down and pull to the lane to the right because they believed The Man was clocking them. It happened frequently.

Your first VMax looks good. I have an '86 in the dark blue (amethyst), waiting its turn. They also had the cast-spoke front wheel, and the rectangular slotted rear wheels like the '85's.

Probably a lot of kids riding now who don't recognize the name of two-time WSB Champion Doug Polen. Here's a great article about Cook Neilson riding Polen's Ducati that Eldo Ferracci and Polen had 'some success' with, you could say. There are many, many racers and tuners mentioned, going back to the 1950's. A great read.

https://magazine.cycleworld.com/article/1993/11/1/one-more-great-adventure

 

[James Massie]

That last pic, a GPZ550?

ZRX1200... my first one....

Blew up on the freeway at about 90... I bought it off the family of someone who passed and they said it sat....it was jetted by that owner and had a fuel cut of switch that if I didn't turn off almost every time, the carb float would stick and flood the far right hand cylinder and lock the cylinder. I didn't know it did it until I tried starting it and the cylinder would lock. I would have to pull the plug and turn it until all the gas spat out. Plug back in and she would fire right up. I guess times like that and the rod probably bent a tad. I knew it would eventually. BOOM!!! Huge cloud of smoke....clack clack clack clack.... clutch in.....clutch out....clack clack clack clack... Pulled over and silver dollar sixed hole blown out of the front of the case. Rod let go of the bottom of the piston...glad it wasn't in a turn/curve. 30 day wait and an eBay crate motor later and back on the road.

Those two-strokes on a tight track, w/a good rider, probably cannot be beat by a bigger bike with your average 'I wanna do a track day!' guy flogging it, thinking he's 'going fast!'

The shop looks like a clean environment. The dyno is a great tool to earn knowledge quickly. The garage w/the black bike under the OH door is your place?

The dyno was at work. The shop was my garage. Long time ago when working in the MC industry. Low pay great discounts...

Did the CHIPs ever hassle you about the siren? That would be an equipment violation here in Florida.

The mounting wasn't illegal here in CA, only the "use." I used the air horn wayyyy more than the siren.... No little beep beep HAHAHAHAHA!!!! OMG people would jump out of the way instead of changing into my lane...

I had a BMW R100 RT Airhead twin, I had it painted in pearl white for the fender and tank, and the wide fairing was candy apple red metallic. It had the wide R100 RT windscreen on it so it resembled a police bike. I realized what use that was when I was behind someone on the expressway, I'd see their eyes in the rearview-mirror look at me, and they would slow down and pull to the lane to the right because they believed The Man was clocking them. It happened frequently.

We have a ton of look a likes around here. Even with crash bar, baton and gun mounts. I see the guys wearing CHP style helmets too!!! lol

Your first VMax looks good. I have an '86 in the dark blue (amethyst), waiting its turn. They also had the cast-spoke front wheel, and the rectangular slotted rear wheels like the '85's.

Probably a lot of kids riding now who don't recognize the name of two-time WSB Champion Doug Polen. Here's a great article about Cook Neilson riding Polen's Ducati that Eldo Ferracci and Polen had 'some success' with, you could say. There are many, many racers and tuners mentioned, going back to the 1950's. A great read.

He was great! So nice! Very easy going and didn't mind getting pulled aside for the photo. I wonder where that put's me in the six degrees of separation along with Erin Brockovich and Jesse Jackson.... My friend met Arnold Schwarzenegger and Leonardo DiCaprio and My ex met Bill Clinton...

https://magazine.cycleworld.com/article/1993/11/1/one-more-great-adventure

 

[James Massie]

Love the article, Thank You! I read that issue back in the day...never thought then that I would own not one but two of the bikes in that issue.

Good times...

 

[Fire-medic]

You're welcome. I subscribed to many of the bike mags in the day, and bought others off the news stand, one of the latter being Backstreet Heroes from the U.K. I have one from probably the 1980's which featured a VMax.

Sadly, the magazines if they exist, are online content. I still prefer holding a magazine in my hands, and admiring the pictures that bleed to the edge of the page. I had Cycle, Motorcyclist, Cycle World, BMWMOA, Hot Bike, and the one that chromed their choice of motorcycle of the year, and put it on their cover. Something Illustrated.

The last several times I've been to Barnes and Noble, I haven't been able to see a single motorcycle magazine, not even ones from the U.K. The times they are a-changin.' My Daytona Bike Week buddy saves his AMCA magazines for me.