On the verge of buying a 2003 VMAX, question about VIN and front brake

[HentaTenta]

Hello. I found a 2003 VMAX with 52000km on it for $4500 cad (which is what, $150 usd? ). Looked at the bike and checked for obvious signs of abuse (scratches, oil leak, fork seal leak, trying going fast in 2nd gear to see if it will pop out, signs of paint, underside, gas tank).
This will (possibly) be my 2nd bike (2004 Honda Shadow vt750 right now), riding since 2017 and don't have mechanic or engineering degree, so I didn't spot anything obvious. Will probably bring it to a motorcycle garage nearby first, the owner wasn't against it .

My first question is regarding the VIN; is the number on the frame supposed to match the number on the engine block/crank case? Because it doesn't, last 3 digits are different. At the same time I checked VIN on my Honda, and they are different on the frame and engine as well. Unless I'm looking someplace wrong.

Clutch felt VERY tight and stiff compared to my Shadow, and so did the steering.
There is some work to be done (speedometer cable snapped when he changed front fork (or so he stated), so have to fix that, all turn signals ripped when he stored the bike (or so he stated). Fork looks like this

Spoiler

The brake calipers are original ,but not the rotors. He swapped them for notched ones, and here's my 2nd question:
When braking, or when slowing down in 1st gear, you can hear the tuck-tuck-tuck noise in the front brakes, but also I can almost feel vibrations in the handlebars when I apply the front brakes, and when I squeeze them harder to stop the bike, the braking power and braking itself is not...linear?
It almost feels scary how the force differs when the notches pass by the brake pads.
On my Honda I can squeeze front brake almost fully and it feels smooth, and I can start braking slightly more "aggressive" at "higher speeds" before stopping.
On this vmax it felt like I have to drop the speed waaay down by downshifting before applying even 50% of the front brake.
Is it just the bike difference, since I didn't ride anything else? That tuck-tuck-tuck gives me the creeps.

Sorry for the wall of text.

 

[Fire-medic]

is the number on the frame supposed to match the number on the engine block/crank case? Because it doesn't,
Answer: no, it doesn't need to match. If you want to set your mind at ease, there are insurance industry websites which have a stolen vehicle registry, and you can input your engine # to see if it shows up as stolen.

You have an 'upside-down fork!' Aftermarket, and probably $2,000 to dig up all the parts to do it right. The entire front end is probably off a literbike sportbike, not sure which one.

Take a look at the front fork bump-stops, the points on the rear of the bottom triple tree which limit the fork movement from side-to-side. I've seen bikes with those damaged or missing, indicating a wreck on that front end sometime or other. You can look for the bump-stops of your current bike, so you know generally where to look.

Look at the rotors to see ig you can feel any grooves when you drag your fingernail against the width of the rotors' caliper contact path. It should feel smooth and not bumpity-bump-bump, grooved. Also see how-deep the groove is, in the middle of the friction pads, from looking straight-down. That is a wear-indicator. If the groove is nearly-non-existant, the brake pads are worn to the point of needing replacement. If you see a deep cut in the middle of the pad on each side, the brake pads of the calipers are new(er). Remember to check the pad on each side of the caliper. Pads can wear unequally, one side may have a deep groove and the other pad on the same caliper may show much-more wear, where the groove is not as-deep. That's caused by a sticking piston or pistons as in the case of the 1993-2007 VMaxes which have two pistons on each side of the front caliper. Your non-stock front end also has two pistons on each side of the caliper.

Sticking brake pads are usually caused by brake dust, corrosion, and water getting to the piston surfaces on their sides, causing them to be sticky, and in a worst case scenario, immovable. Of course, that needs to be fixed before the bike is used.

It appears the front brakes are part of the USD donor bike's front fork and brakes. That is normally what you would expect to have. Literbike/sportbikes have better, more-powerful braking than a bike designed in the early 1980's. That latter is the OEM VMax, which came with 1 piston/side front brakes, from 1985-1992. After that they went to 2 pistons per caliper side, four pistons per caliper, total.

Tell us about the shocks, do they say YSS on the reservoirs, the cans hung-off the rear of each shock, or if not what company is it?

Is the exhaust a 4 into one (only one canister on one side, at the rear of the exhaust. or are there two rear canisters? A 4/1 means a complete aftermarket exhaust, which with the proper jetting can increase your power by 10% or more. There are also complete aftermarket exhausts which have one canister on each side, naturally those are referred to as, 4-into-2 systems. If only the rear canister or canisters has been changed and the front and rear exhaust header pipes are the stock Yamaha pipes, you get a different exhaust noise, from stock, or OEM (original equipment manufacturer) but no added power from that type of system.

If the seller knows, ask him/her to show you the presence of an aftermarket ignition box (CDI box-computer-discharge ignition box), which will have a very-useful function, it has a rev-limiter, which will save your bike from over-revving, which done too-often definitely will cause damage to the bike. The OEM Yamaha Generation 1 bike, which this is (a Generation 1) does not have a rev-limiter. The CDI box is behind the steering stem, between the upper and lower triple trees.

 

[HentaTenta]

Thank you for the reply.
Also, terribly sorry for the confusing description, the picture attached was NOT the actual bike, just the example of the fork installed. I don't know why I didn't attach the photos of the actual bike. Sorry, was tired. Here are the photos that he provided. Exhaust is stock and so is the rear suspension.

Spoiler

Again, sorry for the miscommunication.

If the speedometer cable is snapped, does it mean that the odometer is not functioning properly?

 

[Fire-medic]

OK, onward... .

Speedo cable is probably one of the easiest things on that bike to replace. I'd be surprised if it took 10 minutes. If it snapped, no speedo, no odometer. If there is, the bike is possessed, run-away! Assuming it is snapped.

 

[MaxMidnight]

The forks may have changed the steering geometry which could alter the feel of the steering.
It will be difficult to comment on how a bike feels compared to another (e.g. your Honda) which is complicated by the Max having a non OE front end.
Additionally one individuals perception of what constitutes 'heavy' may well be different for another.
It may just be the angle of the photo but the front mudguard looks somewhat close to the radiator; have the forks been extended or are they the same length as OE? If not were the rear shocks lowered to compensate for the difference?
Check that the head bearings and cable runs allow free turning and that the tyre pressure is correct.

Re the clutch - again, without trying it is difficult to comment but IMO they do need some effort to pull in. Do you know if any mods have been done to the pressure plate i.e. doubling up on the plates, a heavy duty diaphragm or Barnett conversion?

Speedo - do the forks have provision for a speedo drive? If so what bike is the speedo drive off and is it correct for the diameter and profile of the wheels and tyres?
Brakes - assuming you still have the OE m/c cylinder to go with the callipers then it is possibly fair to say they are not the most powerful. That said I'd expect the application to be linear if not that exciting. Nor do the make 'Tuk tuk' noises.
You say they are swapped for notched ones but I can't see what you mean by this from the photos.
Check all pistons are free to move and that one or more is not binding (pad wear may give a clue here).
Also check to make sure some part of the disc isn't catching on the rotor when applying the brakes.
If you are feeling vibration (pulses?) back through the handlebars or brake lever then this could be indicative of thickness variance on one or both discs. This should be less than 5 thousandths, not something that is easy to measure. Thickness variation will push all pistons out which displaces brake fluid which will act on the m/c piston and through the lever. (Note disc run-out is less critical because as one piston is pushed out the opposite side goes in and no brake fluid is displaced).

 

[Fire-medic]

MaxMidnight, that picture is not the bike! The O.P. is using it as a generic depiction of what the bike is.

I am in agreement with your recommendations to the O.P. If they buy this prospective bike, and until some pics are posted, we are only speculating about the actual issues.

I'd have to go back perhaps 50+ years to give a comparison about handling/performance/braking 'feel,' from my Honda 305 Scrambler, compared to my brother's RD350 predecessor, the venerable R5 350 parallel-twin two-stroke and its TLS large front brake compared to my drum brake, or the way the two-stroke would loft its front wheel with a handful of throttle. Similar displacements, but much-different feel to the controls.

 

[HentaTenta]

Thank you for all this info. For sure, it's hard to provide more advices without me posting pertinent pictures and exact details of the bike. I've seen the bike only once, so I I'll bring up my questions with the mechanic when/if I bring the bike for an inspection. Until then, again, thank you for your help. Just browsing through the forum, this community looks like a treasure trove of enthusiasm and know-how.