My European 102hp has more torque than an American 145hp?

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145h owner also told me about tyres, but wobbles also at 40kmh
Don't think tyre shape may affect that strongly at such a low speed
I think about what Skrimps posted regarding bounce test and tightening
Dis you check that already and still wobbles?

Yes, I replaced the steering bearings and adjusted them using the bounce technique. (...and rechecked the bearing tightness after ~2k miles)

Like I said, it's not a problem. You would never notice it with your hands on the handlebars.
 
How about if you leave choke on just a little? I had full power -97, and push was anything but moderate at all rpms, though I didnt have anything to compare 😄
That was brilliant 😂
Damn I going mad

I'm bothering all this forum with this thing
I reduce to one question

Is the 102hp practically the 145hp without vboost?
Or is the 145hp different in carbs or other things to make it smoother lowend?
 
Yes, I replaced the steering bearings and adjusted them using the bounce technique. (...and rechecked the bearing tightness after ~2k miles)

Like I said, it's not a problem. You would never notice it with your hands on the handlebars.
Thanks
But even with just one hand this bike quickly started wobbling VERY strong btw
 
If you use the 'advanced search' function you will probably turn-up >100 threads (apiece?) about speed wobbles, steering instability, 'shakes,' steering head brinelling, loose swingarms, loose/worn steering head bearings, worn front fork bushings, cupped tires, insufficient tire air pressure, blown fork seals, no air pressure in the forks, bad wheel bearings, worn-out rear shocks, fork dampers, and other ways that your bike can develop 'the wobbles,' and ways to deal with that.

A thorough inventory of each of these is the systematic fashion to identify and to solve such an affliction. Keeping a journal of what you did, how you did it, and what were the results will provide you with a documented history of your efforts and your results.
 
If you use the 'advanced search' function you will probably turn-up >100 threads (apiece?) about speed wobbles, steering instability, 'shakes,' steering head brinelling, loose swingarms, loose/worn steering head bearings, worn front fork bushings, cupped tires, insufficient tire air pressure, blown fork seals, no air pressure in the forks, bad wheel bearings, worn-out rear shocks, fork dampers, and other ways that your bike can develop 'the wobbles,' and ways to deal with that.

A thorough inventory of each of these is the systematic fashion to identify and to solve such an affliction. Keeping a journal of what you did, how you did it, and what were the results will provide you with a documented history of your efforts and your results.
Thanks will do
 
I read with interest F_M's write-up above that says quote ' worn-out rear shocks'. I'm not saying this is your problem but it should be considered as I once had a set of rear shocks that ended up having the spring tensions uneven. I went into a wobble at about 120 MPH and it held the wobble right down to stopping, it was really bad and I've always been very wary of rear shocky's maybe leaking or tensioned unevenly or otherwise. Never experienced it again after changing them, but it was one of the closest ones I've ever had. To emphasise how severe it was, I was 20 years old and I'm 60 now, and it sticks in my head whilst out riding at higher speeds.
 
I went into a wobble at about 120 MPH and it held the wobble right down to stopping, it was really bad...
Geez, why didn't you just do what the 'experienced' riders do? "I had-to 'lay 'er down!" That one always makes me laugh. You initiate a wreck to avoid a wreck? I suspect the experienced racer might be able to avoid worse hurt because they know how-to fall off a bike with less of a chance to snap a long bone or two, but being in-control of your bike and using counter-steering to avoid an impact sounds like a better way to survive a get-off with minimal trauma. Ever-notice the open-wheeled car racers get into a wreck? They release the steering wheel completely, and cross their arms on their upper chest.

Screwloose, I'm glad you survived to be able to make it home and to change your underwear.
 
Geez, why didn't you just do what the 'experienced' riders do? "I had-to 'lay 'er down!" That one always makes me laugh. You initiate a wreck to avoid a wreck? I suspect the experienced racer might be able to avoid worse hurt because they know how-to fall off a bike with less of a chance to snap a long bone or two, but being in-control of your bike and using counter-steering to avoid an impact sounds like a better way to survive a get-off with minimal trauma. Ever-notice the open-wheeled car racers get into a wreck? They release the steering wheel completely, and cross their arms on their upper chest.

Screwloose, I'm glad you survived to be able to make it home and to change your underwear.
Yes I’m now a traumatised wreck, how was I to know it would end up like that. Saving the bike was the best option at the time for me :), it’s a youth thing.

Also got the shocks changed then underwear 🩲, in that order 😂. Thanks.
 
I read with interest F_M's write-up above that says quote ' worn-out rear shocks'. I'm not saying this is your problem but it should be considered as I once had a set of rear shocks that ended up having the spring tensions uneven. I went into a wobble at about 120 MPH and it held the wobble right down to stopping, it was really bad and I've always been very wary of rear shocky's maybe leaking or tensioned unevenly or otherwise. Never experienced it again after changing them, but it was one of the closest ones I've ever had. To emphasise how severe it was, I was 20 years old and I'm 60 now, and it sticks in my head whilst out riding at higher speeds.
Wow that must have been scary, can figure out how it is stuck into your mind! So good it went someway smooth!
In this bike though I guess more about front tyre due being unused, and/or bearings
 
Hey all helping guys! Guess I had an idea about lack of power (or it might be ********! You'll tell)
The seller told me he bought this bike in Germany and it was imported from USA.
So I wondered could it be some different version compared to your full American? The vis begins with: JYA2WEE
googling vmax JYA2WEE always takes to Japanese websites, and some Russian websites
Is there any way to check specs/version from vin?
Maybe this could be a version with vboost but with some restrictions too...
 
Then you have a REAL problem.

Like I mentioned before, I have had REAL wobble/weave problems that were caused by steering bearings and tires. Firemedic described numberous other potential casues.
That's my fear. If I clear the torque issue and buy this bike all let all the wobble deeply inspected
 
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Assuming the information you have input and the Yamaha Model Index 1958 - 2008 are correct then yes it is a US 49 state model in Yamaha Black.
Thanks
Then I'm still going mad on why this bike is so soft in low rpm!
 
What is funny about trying to leave choke SLIGHTLY on? If it don’t get enough fuel on lower rpm -> no go, after vboost opens it gets fuel -> go. Usually there is other symptoms with ****** carbs too, but that is easy test. Worth a laugh I’d say.
 
Can I give a suggestion. Apologies if it has already been said before.

The American model would have the a/f screw plugged off (maybe) and if the trouble is at low rpm where the pilot screw adjustment is essential, and also being an old engine. Then drill out the a/f plugs, take out the screws and put new rubbers in, blast out with carb cleaner, and adjust the screws. Then balance the carbs. Its just what I would try.

For wobble, I would still consider shocky’s and forks as when I mentioned above, I should have included that when I went into a wobble it felt like a front end problem at the time with maybe a flat front tyre (and if have had one of them at speed like I have, then I do not need to elaborate further on the fight you have trying to hold on right down to stopping). Yes I held onto that one also 😝, when your young your legs are worth less than the bike 😂
 
What is funny about trying to leave choke SLIGHTLY on? If it don’t get enough fuel on lower rpm -> no go, after vboost opens it gets fuel -> go. Usually there is other symptoms with ****** carbs too, but that is easy test. Worth a laugh I’d say.
Ah my bad then!
I thought it was a joke
As soon as I'll be able to ride that bike again (lives in a other town) I'll do it thanks
 
About the 'choke,' it's an enrichener. Yes, more fuel is introduced to the engine. A traditional choke is a simple plate blocking-off the air inlet to varying degrees, according to its position. The same amount of fuel is presented to the engine, but the amount of air is less, causing an enriched mixture to the engine. The VMax works by supplying more fuel, the CV carb slides still flow the same amount of air.

Recently one of the members discovered their enrichener plungers weren't synchronized. They weren't allowing the same amount of additional fuel to enter the fuel venturi pathway. A good cleaning of the brass plungers, lubrication, and carefully ensuring that the rods and lever system opening and closing the enrichener pistons was functioning properly was needed. See the pic:

VMax carb choke out of adjust..jpg

If you own a VMax, either you pay-attention to the condition of the fuel delivery system, or you have problems. A clean gas tank, meaning no rust, and unobstructed pilot jets in the jet block will allow you to have a decently-performing bike which idles properly, doesn't have any low-speed issues, is easy to synchronize the carburetors, and which operates as it is supposed to behave.

Over time, certain gremlins arise. Intake leak(s) can come from a variety of places. The points of connection of the airbox to the carburetor bellmouths, the lower carburetor bodies' attachment to the VBoost manifold, and the VBoost manifold's O-rings to the cylinder heads are all places where air infiltration can cause you to pull-out your hair until you discover that/those leak(s).

Other likely places for leaks are deteriorated fuel lines. Say you bought a 1988 VMax, and you're having issues. Think about the age of the bike, and whatever service it has, or hasn't-had. The molded T-line to service the carburetor bank is original to the bike, most-likely. It's 33 years-old! As are the other rubber components, including the CV carburetor diaphragms. The gas tank is rusty. Fine particulate material from that rusty tank is plugging your pilot jets, and that's what when you have the bike idling, one or more of the pilot jets has become obstructed by sediment/rust particles. Sure, try the 'peashooter,' try the 'shotgun,' or go straight for the cure: pull the carburetors, split them into-two, and remove the float bowls, remove the jet blocks, and then remove the gas delivery jets, and clean the jets and their passages. You want to be able to see light at the end of the jets' tunnels! The carburetor bodies also need to be cleaned, for this purpose, an ultrasonic tank is what I consider to be the best way to do this.

VMax carb float area.png

While the carbs are apart, check for proper fuel level, you can use the carb body casting behind the float for a rough starting point, but a 'wet-check' will allow the best fuel delivery and best gas economy. If I open the carbs on a new to me bike, the float needles with their Viton-rubber tips are replaced, and the brass seat they go-to is cleaned.

VMax FloatLevel bowl off.jpg

Have new jet block gaskets on-hand for the tear-down, because they inevitably tear when you try to remove the jet blocks.

VMax carb jet block gaskets.jpg

About splitting the carburetors into two banks: to do this, you need to work around the molded-rubber T-line, and don't be surprised if your 33 year-old rubbers fall-apart. Thank Yamaha for still allowing us access to as-many parts as they do for our bikes, because when they decide to stop supporting the replacement parts, the value of your bike is going to plummet. Some parts are now unavailable, but thankfully there is a cottage industry of what the UK members know as 'breakers:' people who part-out the bikes. They will be the resource of last-refuge when the lack of OEM, new parts happens.

Currently there are suppliers of the rubber donuts used for the carb joints and the CV slide diaphragms. Surface cracks on the rubber donuts which don't leak air will still provide proper air levels. use the old method of spraying something like starting ether, carb cleaner or another aromatic hydrocarbon on the boots or the cyl. head-VBoost joints, and listen for the increase in rpm's, a sign you have located a leak. Don't stop at that one leak, continue to search for more. In the case of an O-ring leaking at the VBoost to cyl head point, replace all four of the O-rings since it's apart. it is likely that disturbing the seal all four O-rings have will cause the others to leak, so replace them-all.

These tips are based on my work on these bikes for nearly 30 years, they represent issues I've dealt-with on multiple VMaxes. Remember that no-matter how-well that you clean all the parts in that set of carburetors, replacing anything which could be causing an air leak, or removing deposits which plugged-solid your pilot jets, if your gas tank isn't shiny-clean inside, you're just going to soon find your pilot jets are plugged again as an uneven idle, cold exhaust header(s) at idle, and poor throttle response off-idle happen again because of rust in the gas tank. Removal of the gas tank isn't difficult, follow Buster's how-to, and if you decide to use a kit to line the gas tank, follow the directions exactly or end-up with more problems than you began-with. Heed the input of the specialists on-here, who work on these for a living, people like Sean Morley, danymax for the carburetors, Captain Kyle and Damian, they are the subject matter experts whose experience and knowledge collectively have see anything you're experiencing with your ride. Here's an example of something I had happen, the bike ran, but was obviously not running properly, and fortunately, the position of the cam when it happened was not on the lobe, so there was no piston-to-valve interference, which would have been a much more-involved repair.

VMax broken cam.01.jpg
VMax broken cam.02.jpg

Once you've dealt with your issues, and solved them, put your experiences here so we all can see what worked for you. You will be helping the next fellow with a similar issue or issues.
 
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