Odd 5th Gear?

[Drew]

Sounds internal from you description, but it might not be.

Oil is cheap, so do a simple test. Into a clean container, drain your oil. There will usually be some metal on the magnetic sump plug, but not heaps. Also, there shouldn't be fuck all in the oil in the container after it is drained.

[Glowerss]

I'll do an oil change tomorrow then n see what comes out. Hopefully nothing malignant

Good news, I guess, is George from Moto doctors is coming over to do an inspection on the bike I'm selling for some other bloke. Might be able to fleece him for some info before he scoots after hes done I suppose.

[Akzle]

Assuming it isn't the chain/sprockets, does it sound like something thats likely to get worse and eventually break something serious? Or potentially just a "character feature" ?

I realize it's hard as to give a guess over the interwebz! Definitely plan on having it serviced soon as the old bike sells, but would like a guess at how vigorously I should be persuing it.

if i twere yu, i would rule out teh chain and sprockets. by checking the chain and sprockets. make sure chain is adjusted properlike. usually that's 1-2" of sag if you're palming it solo.

a gearbox split is a bit more than a "service".

if the other guy is right, and it's missing teeth, it's facking dangerous. a rear wheel lockup is going to be interesting at 5th gear speeds, not to mention engines don't like going from thousands of revs to no revs, shortly. things like crankshafts especially.

if i'm right (far more likely, by anyone's measure ) and it's shit in the pinions'es teethses, it will not be catastrophic until the tooth breaks off (see above) however, better dealt to sooner than later, though.
if your sump plug isn't magnetised, get a magnet and stick it on the outside. neodymium is cool. go for a ride (warm oil, and shit stirring), then drain it.

[bogan]

Here's an out of the box (well, technically its about leaving it all in the box) idea. How about put the bike into 5th on the center stand, put a bit of clutch on for a constant drag (may need to get your mate to help here), and turn the rear wheel by hand. You might be able to feel where it is going wrong, and by the feel of it, work out what has gone wrong.

[Akzle]

Here's an out of the box (well, technically its about leaving it all in the box) idea. How about put the bike into 5th on the center stand, put a bit of clutch on for a constant drag (may need to get your mate to help here), and turn the rear wheel by hand. You might be able to feel where it is going wrong, and by the feel of it, work out what has gone wrong.

((he had to ask KB about this shit, finding the spot on teh gear isn't going to help him much, tell him to start marking shafts and working out reduction ratios... he's going to shit.))

in fifth you should be able to turn the engine over quite easily by spinning the rear wheel...

[pete376403]

What sort of engine revs is it doing at 50k in 5th gear? I'd expect a little 4 cylinder motor to want to be spinning fairly well and at low-ish revs it may not be making enough power to pull 5th gear smoothly. (otoh, if its a six speed and can pull similar revs on 6th without issues then its something else)

[Glowerss]

She pulls pretty damn well at 4-5k RPM in 5th without much problem. Same in 6th really. 6th gear you can go from 50-60kph all the way up. Has some fairly fuckin good pull for a 250 IL4 really. Pulls infinitely harder lower then my ZZR250 did.

It doesn't seem like its struggling to pull in 5th at lower RPM.

Iunno it could be chain/sprocket. Will give it a check tomorrow once home from work.

The chain was admitted to be a cheap shit chain from the guy selling it, and the bike had been sitting for a month-month and a half I bought it. The guy selling it and NZspokes on here did an oil change on it before letting her sit, and they said there was nothing dodgy in the oil then. Both reckoned it was running fine before sitting. Chain looks a bit rusty on the outside, don't know if that would affect anything.

I don't know the guy selling it very well, but I'd trust anything spokes would have to say about it.

[ducatilover]

Have you tried loading it up at the same revs in every gear? (I'm assuming you have)
I think it'd be doing around 4500 in 5th at 50?
And does it start it from right down in the revs (say 2500) and where does it become less noticeable?
I wouldn't think it'd be having gearbox issues, they're generally very strong in the box (I had a missus like that)

I'll be up that way next week, I could come flip it and then you can stop worrying about it?

[Glowerss]

Have you tried loading it up at the same revs in every gear? (I'm assuming you have)
I think it'd be doing around 4500 in 5th at 50?
And does it start it from right down in the revs (say 2500) and where does it become less noticeable?
I wouldn't think it'd be having gearbox issues, they're generally very strong in the box (I had a missus like that)

I'll be up that way next week, I could come flip it and then you can stop worrying about it?

Yeah, it's around say 4500-5k rpm at 55-60ish in 5th. Finding a smooth road around my place that's quite is an absolute bugger. Bunch of munted bumpy ass roads here makes fiddling with things a right pain!

Piddling around today, I didn't test 6th, but it's definitely absent of anything in 1st through 4th. I'd have to find an absolutely glass smooth road to know for sure 4th is OK, but it feels fine comparatively to 5th.

To clarify, it isn't.....like running over cats eyes lumpy. It really is bumpy road sort of shit coming through the pegs and seat. You wouldn't know it was there going over a crappy road. But on smooth tarmac, it's pretty obvious. It's very regular, and changing gears clears it out immediately.

Anyway, I pissed around on the roads near my house when I could find some clear stretches. 1-4 are fine. 5th it's much less noticeable below say 4k rpm, and becomes more evident the more throttle on you have. I took it up to 80kph and it didn't really become less noticeable, just more frequent.

It does appear to only occur on throttle on. If you're coasting it's completely fine. Minor if you're gently on the throttle and then very evident if you're maintaining or speeding up.

I checked the chain today. Nothing screams at me as being drastically wrong. You can pull the chain off the sprocket a bit, maybe a millimeter or two (I suck at metric, probably a quarter of an inch or slightly less). So it might be a little bit loose but nothing drastically wrong to my untrained eye.

[nzspokes]

[QUOTE=Glowerss;1130428820]Yeah, it's around say 4500-5k rpm at 55-60ish in 5th. QUOTE]

Try riding in a better gear. thats way to low in the RPM for that speed. You wont be able to react. Its sweet spot will be around 7 to 8 k i would have thought.

[Maha]

[QUOTE=nzspokes;1130428823]

Yeah, it's around say 4500-5k rpm at 55-60ish in 5th. QUOTE]

Its sweet spot will be around 7 to 8 k i would have thought.

A little higher up Rob if you want her to come back for more.....

[Glowerss]

[QUOTE=nzspokes;1130428823]

Yeah, it's around say 4500-5k rpm at 55-60ish in 5th. QUOTE]

Try riding in a better gear. thats way to low in the RPM for that speed. You wont be able to react. Its sweet spot will be around 7 to 8 k i would have thought.

It doesn't matter a whole lot if you're just cruising down a 50kph in traffic really. Either way, speeding up doesn't seem to make much of a difference. It was still off at 80kph which is probably around 8k rpm. I can cruise in 6th actually at 50kph and its smooth as

[Akzle]

I checked the chain today. Nothing screams at me as being drastically wrong. You can pull the chain off the sprocket a bit, maybe a millimeter or two (I suck at metric, probably a quarter of an inch or slightly less). So it might be a little bit loose but nothing drastically wrong to my untrained eye.

chain tension is measured about half way between sprocket centres. should have about 1-2" sag/movement up an down like.
if it has less, then when you put your fat ass on it, it will become taught, which f*cks shit up.
it it has more, you'll get similar symptoms to what you describe, but usually through all gears, and slowing up as well as speeding down, as the rollers miss the pitch...

...nothing to do with pulling it off teh sproket

[Drew]

A 1/4 inch is 6.35mm. If you can pull the chain that far off the sprocket, at the rear most part of the sprocket, you need a new chain...nomatter what else...no question...I feel I've made my point on this note.

Anyhoo. I doubt it will be that simple.

[Glowerss]

chain tension is measured about half way between sprocket centres. should have about 1-2" sag/movement up an down like.
if it has less, then when you put your fat ass on it, it will become taught, which f*cks shit up.
it it has more, you'll get similar symptoms to what you describe, but usually through all gears, and slowing up as well as speeding down, as the rollers miss the pitch...

...nothing to do with pulling it off teh sproket

Ok, yes I'm an idiot and was "doing it wrong". Assuming I'm doing it right this time (measuring the travel distance of the top of the chain at its lowest point to the bottom of the chain at the highest point in the middle most part between the two sprockets) it looks like theres a slack of well over 2" (it's being stopped from going higher by the swingarm ) Looks like a good place to start!

A 1/4 inch is 6.35mm. If you can pull the chain that far off the sprocket, at the rear most part of the sprocket, you need a new chain...nomatter what else...no question...I feel I've made my point on this note.

Anyhoo. I doubt it will be that simple.

Yeah, you're right. My guess was way the fuck off Sticking to rulers from now on.