RZR Revival?

Life Cars & Motorcycles
81

Thanks for the info. Figured I’d probably have to take the engine out if it got to a geartrain strip.

I take it you think, given my rather brutal method of freeing the clutch, that the gearbox probably is damaged and I’m unlikely to get away with just clutch cleaning/adjustment?

I don’t mind buying an impact driver, quite like buying tools, I’ve just never found, in my hands, that they actually worked.

As I think I said earlier, I found a crank handle with a multi-bit adapter very useful mfor applying pressure and leverage. though you need a bit of room/access to use it. Might look for one of them too. A ratchet brace and bit would be better but getting a bit-holder to fit would be difficult. Shopping trip to Kaoshiung.

My impression (and its not worth much) is that the critical thing with cross-heads is that the bit fits perfectly, but its quite easy to slightly misjudge that, especially if its in a hard to reach spot. I’d think this would also apply if the bit is in an impact driver.

If I can find a source later I might replace the cross-heads with (perhaps stainless) bolt-headed machine screws.

82

My best guess, considering probable cause, and symptoms, is that the first gear selector dogs, and/or the holes they engage in, are chewed up so the gear isnt effective, but there’s some intermittant residual drive from friction between the selector face and the gear face.

I dont, however, see why that would make it stall, which it did a few times. Maybe that was just my bad, stressed out driving. Maybe the gears were locking up on debris, which would imply extensive damage.

I’d expect to see more debris, but maybe they get caught somewhere and dont/havn’t yet make/made it to the bottom of the casing.

Worst case would include damage to the output shaft splines.

Best case would be that problem is solely due to clutch drag, but I think it probably isn’t.

Four main (groups of) questions:

(a) Is there any way to confirm this short of dismantling the geartrain?
Can I see the selector dogs, perhaps with a dentists mirror or similar?
Dumb question, and perhaps I can work it out, but which end of the shaft is first gear at? I THINK its the furthest away end looking from the clutch cover.

(b) Assuming there ARE debris lodged near the geartrain, where are they likely to be and is there any way to get at them. (short of dismantling the whole geartrain) both to confirm diagnosis and to avoid further damage?

© (Perhaps dependant on (b)) can I reasonably expect to be able to get through a registration inspection with no first gear?

(d) Is the gearbox known to share components with any other machine, which might be available from Yamaha or a scrappy?

83

I honestly cannot tell from your description what the root cause is. You could have just bent a selector fork hammering the lever into gear. They cannot easily be straightened and good luck finding one. IIWY I’d take MJB up on the offer of a spare bottom end. Strip both down and mix and match the gearbox parts. Just remember to take whole pairs of gears as they wear together.
I’d for sure want to strip the 'box and inspect everything carefully. If you have a lot of debris in there you should replace all the bearings as a matter of course. Lucky for you, all the bearings in the RZ motor are standard sizes you can get from any industrial bearing supplier. Honda are bastards for using one bearing in every engine which is proprietary just so they can decide when these bikes will go the junkyard.

84

Took the clutch stack apart and cleaned it up a bit. Very hard concretion (I’d guess metal dust, clutch material and oxidised oil) on metal plates which was probably what stuck the stack.

Centre pushrod no longer pushes on re-assembly, so I guess whatever was on the end of it (ball bearing?) isn’t there anymore. Didn’t see anything fall out, but I’d be quite likely to miss that, or perhaps its just internally displaced rather than dived down a drain.

Spose I’ll have to open up the other side tommorrow and see if I can find it.

Edit: Todays tomorrow. There’s no access from the other side so I guess if anything is “internally displaced” its a full dismantle to fix it. Thought it might be the locknut on the end of the pushrod was adjusted wrong so fiddled with that endlessly but couldn’t get the endplate to move, though there’s very slight movement of the pushrod when the endplate is off. Figured I’d break something else if I continued working in full sunlight (wont do that again) so I gave up. I guess I’ve probably put it back together wrong, though I don’t see how.

Noticed the kickstart lever is cracked. Didn’t think I was that strong. Rage Against The Machine / The Power of Petulence.

85

Third time lucky. Surprising how much easier things are in the shade, without mosquitos. Fiddling with the pushrod locknut plus putting the pressure plate in right (There’s only one correct orientation, the other three have too much clearance) got the plate moving what looks like a reasonable amount.

Not sure if the spring bolts are supposed to be screwed “home” (i.e. fully seated / compressed) or just until there’s a “reasonable” clutch lever pressure, but I’ve done the latter for now.

Kickstart mechanism fell out. Looking for pictures to guide putting it back the right way. Looks straightforward but I’m not sure where the recoil spring (or whatever its actually called) anchors.

86

The screws for the clutch springs go all the way ‘home’.

The kickstart return spring is a little fiddly, but when you remember which direction it’s supposed to recoil, and to what position, it’s pretty easy. There’s a hole or a corner in the casing to hook it into, there should be a little preload on the spring when the case goes on.

87

[quote=“redwagon”]The screws for the clutch springs go all the way ‘home’.

The kickstart return spring is a little fiddly, but when you remember which direction it’s supposed to recoil, and to what position, it’s pretty easy. There’s a hole or a corner in the casing to hook it into, there should be a little preload on the spring when the case goes on.[/quote]

Yeh, bleedin’ obvious when I looked at it again. I was interpreting that hole as a case screwhole so hadn’t considered it. Duh!

Edit: Of course I didn’t find any very relevant pictures, but to save this almost completely useless mechanical factoid from oblivion, I wish to point out that the kickstart from the 1982 Yamaha XT200 looks identical and probably is.

Bought an impact driver to try on the stuck and slightly damaged oilpump cover screw before I resort to the hacksaw. No sausages whacking it with my smallish ball-peine hammer, so I bought a three pound mallet and whacked it pretty hard with that. Still no sausages and I’m afraid to hit it much harder in case I crack the casing.

I suppose I should have got a more expensive one but this was all I could find locally “Thorsen Professional” never-heard-of-them-brand, 300nt. “Lifetime Guarantee”

Well, its not VERY professional. Its got a bit of money out of me without doing anything useful, but only a bit, and unlike the Taiwanese medical profession, it hasn’t tried to kill me in the process, at least not yet.

[Edit:Looked them up and, assuming this isn’t a fake (must check exact spelling on the box) they should be OK. Practical AutoMechanics award for what looks very like a premium handcart, even. So serendipitous its spooky, sometimes.]

88

The trick with impact drivers is first to get just the correct bit size. No good if it’s too big or small. Then, make sure the driver is rotated over the cam by fitting the bit into the screw head and turning the body in the direction you want to turn the screw, until it is locked up solid. Then take a good swing with your lump hammer. You want to use a good dead blow. Don’t let the hammer bounce back off the driver. It can take a few hits to start it moving. Make sure each time your driver is loaded up in the right direction.
If you are damaging the screw head, just stop and go get the correct bit for the job.

89

[quote=“redwagon”]The trick with impact drivers is first to get just the correct bit size. No good if it’s too big or small. Then, make sure the driver is rotated over the cam by fitting the bit into the screw head and turning the body in the direction you want to turn the screw, until it is locked up solid. Then take a good swing with your lump hammer. You want to use a good dead blow. Don’t let the hammer bounce back off the driver. It can take a few hits to start it moving. Make sure each time your driver is loaded up in the right direction.
If you are damaging the screw head, just stop and go get the correct bit for the job.[/quote]

THINK I was doing that but maybe the bit wasn’t an absolutely perfect fit. As well as the correct bit, would it be worth getting a “dead blow” hammer? Never used one, but I’ve noticed them for sale in a couple of places recently.

90

[quote=“Ducked”]
THINK I was doing that but maybe the bit wasn’t an absolutely perfect fit. As well as the correct bit, would it be worth getting a “dead blow” hammer? Never used one, but I’ve noticed them for sale in a couple of places recently.[/quote]
I’ve never owned one. Just aim your blow to end somewhere past the driver head, not on it.

91

and mind the web in between the thumb and palm, as that hurts like hell when you get it caught between the moving part and the stationary part of the driver.

Ouch.

gets a good blood blister developing too…

92

[quote=“urodacus”]and mind the web in between the thumb and palm, as that hurts like hell when you get it caught between the moving part and the stationary part of the driver.

Ouch.

gets a good blood blister developing too…[/quote]
Tru dat. Mind you, you’ll only make that mistake once!

93

Stripping and cleaning the clutch has reduced gearchange difficulty. First is still problematic, have to really kick it sometimes, others it goes in but with a more noise than normal, so I guess first gear and/or its selection dogs is/are damaged, but the others now select apparently OK, implying some of the problem was drag from the encrusted clutch plates.

Both the friction and bare metal plates seemed quite worn (though I didn’t have specs or a new set for comparison), and if they arent slipping now I guess they soon will be.

Are replacements available?

94

Two or three times. me stupid.

95

Actually got an impact driver (I think the third I’ve owned) to work on a stuck screw! (I think for the very first time in my life).

I guess the poor record is partly because I only try them when all else fails, and by that time the screw is usually chewed up. I hacksawed a deep and fairly close fitting straight slot in this one (using double blades), using a flat bit in the impact driver.

Result! Didn’t even hurt my hand.

My impression is that cross-head screws are far more trouble than they are worth, but I guess if one is using power tools the bit is easier and quicker to locate.

96

This engine seems to be drinking its gearbox/clutch oil, which may explain some of its smokyness, though I’ve only just got the oil pump cover off on this one so am still currently running premix.

I wonder how harmfull it would be to use 2-stroke oil (which should burn cleaner) in the gearbox? Most 2-stroke oil doesn’t seem to give a viscosity on the bottle (except for a “local” brand I can’t remember the name of which says 10-20W, though the significance of a multigrade 2-stroke oil is unclear to me) but I’ve heard its “generally” about 20W. Clearly this is not going to lubricate as well as 40W motor oil, but one could use a little more which might partially compensate, as well as cater for the rapid loss.

I think, in case the seal “spontaneously” recovers, I’d have to ignore this oils contribution to the lubrication “budget”, so the engine is still likely to be over-lubed, and consequently running lean.

97

The oil seal that separates the crankcase from the primary drive case is leaking. As the crankcase cycles below atmospheric pressure to pull in the next lung-full of mixture, it pulls some of the oil in the primary drive case through the seal.
Unfortunately, the case has more air in it than oil. You also have a primary air leak so you cannot accurately control the mixture. As well as losing your lube, you will find it gets progressively more difficult to start the engine, requiring more choke to start. Idling will become more erratic and you will have to increase the idle speed ever higher to keep it running. Power and throttle response will also worsen. Bad situation all around.

What you need to do is remove the clutch again, remove the primary gear from the end of the crankshaft, and expose the seal. There might be a thin steel cover over the seal as well, but that could be the NSR. I forget.
careThe seal is fitted from the outside, so you can replace it without splitting the cases. Take a suitable punch or flat-blade screwdriver and with a hammer gently tap through the seal. The shell of the seal is steel, but it’s just a thin stamping. Just be gentle so the screwdriver doesn’t rap into the crankshaft bearing which is just behind the seal. Once you have holed the seal you can lever it out carefully with the screwdriver. If it’s still too tight, make a few more holes in it until it deforms enough that the tension on the outer diameter is reduced. Clean everything up nicely and check there isn’t a deep ridge cut into the crankshaft.
Find a length of steel pipe or a large socket to drive the new seal in. Just make sure it goes in nice and straight. Drive the seal in until the face is flush with the crankcase all around. It’s not a hard job if you take your time.
With a new seal in place you should be able to tune the carb properly and it will stop drinking the gear oil.
The seal is a standard size btw so even if Yamaha don’t have them (I’m sure they will) you will get one from an industrial seal supplier. A plain old NBR seal will be fine, get a Viton seal if they have them.

2T is not a great substitute for gear oil btw. You would have to change it very often as the action of the gear faces sliding over each other shears the long chain molecules very quickly, reducing viscosity.

98

A little out of topic but is it cheap to buy a used RZR? 25-30k ?

99

I think Ducked would be very happy to sell you one for that price. :whistle: :wink:

100


Here’s one that looks good.
Check it out here…
tw.page.bid.yahoo.com/tw/auction/c45727228
This is how most of them looked when I first came to Taipei back in 1998 and what I saw most of around the streets and so what I went out to buy, before I saw a row full of NSRs at the bike shop…
Still got the same NSR:happybiker: