GZ125 chain replacement

[EzyRider]

Right then, been reading a lot of the topics on here for a while, now it's time to try and get the answers to my questions...

I have a Suzuki GZ125 (58 Plate, the K8 I believe) and I think the chain/sprockets need replacing... First, I take it they have to be done as a set?

Second. I believe it is as the 250 and a 15T front as standard? I have read the guide on fitting a 16T front sprocket, would a 125 cope with this? or would it just kill it with it's limeted power?
Looking to get the revs down a bit at the 'higher' speeds...(Though I can only get 70 out of it!)

Will the 250 workshop manual be the same as the 125? I cannot find a workshop manual for the 125 of this age anywhere!

Can anyone point me in the direction of or tell me the detials of the chain and sprockets required for the 125?

How much of an in depth job is a chain replacement? I used to be a mechanic, but never touched bikes...

Sorry for the list of questions! Any advice you can offer is much appreciated!!

Cheers all!

[JWR]

The GZ125 never came to North America.

I believe the bodies are the same.
You have to cut the chain to remove it.
You will have to use a master link to put the new chain on.
The sprockets are easy to remove and change out.
There should not be lot of difference in prices from a dealer or parts warehouse .
The 250 really does not pull the 16 tooth sprocket well.
The workshop manual will give you all the information that you will need.

http://www.motonet.biz/eshop/front-sprockets-jt/

[EzyRider]

The 250 really does not pull the 16 tooth sprocket well.




So I'm guessing then that if the 250 doesn't like the 16T the 125 will be even worse...
Do you know the weight and BHP of the 250 off the top of your head?

Cheers for the link, will have a look on there.

What chain type would you recomend?

[Jvacustoms]

The 250 really does not pull the 16 tooth sprocket well.

So I'm guessing then that if the 250 doesn't like the 16T the 125 will be even worse...

I would say that if it is performance/speed outta the bike that you are looking for, Dont use the 16t.

If you are rather, trying to make the bike's tasking easier for it to manage at normal speeds and average use, then use the 16t.

I personally like the acceleration of the 250 with out the 16t it is quite... "Peppy" and with the 16t it just lost its "peppyness" and became rather boring. So i changed it back after 3 weeks and it has sat on my workbench since.

[EzyRider]

I'm not so worried about the speed, the majority of what I do is city commuting miles so around 30 - 50 mph I'm rarely on a road that allows 60, let alone 70 (and being on a 70mph road on a 125 is a scary experiance...)

So really I'm looking to drop the revs slightly when doing say 50 - 60 as that's when it starts to scream...
So would you say there is much loss in acceleration upto the 50-60 mark?

[Gz Rider]

...

[EzyRider]

Interesting...

Might need to look into this a bit thurther before making any changes from the factory standard.
What is the easiest way to work this out? Find out the number of teeth, then work out the ratios from teeth numbers, then what next?

[Gz Rider]

...

[EzyRider]

Unfortunately 125 owners seem pretty hard to come by full stop... Might be simpler to leave it as it is I think.
The chain needs changing either way so will do that and maybe have a hunt around and bide my time before doing anything rash!

[alantf]

Hi there, & welcome to the madhouse. I see that you're from Great Britain. Whereabouts exactly, because that description fits England, Scotland, Wales & Northern Ireland. Are you a Paddy, Jock, Taffy or an Englishman. :whistle: :roll:

BTW, you asked if you needed to change the front sprocket at the same time as the chain. Check the sprocket for wear. If it's not worn, then there's no need to replace it. The same goes for the chain. Check it, & make sure what condition it's in. It's more than likely that all that's required is a good clean & lube (plus setting to the correct tension). :2tup:

There are quite a few GZ125s, here on the island. Most of our speed limits are 50kmh (30MPH) so they're quite adequate for the job. Don't know anyone, personally, who's got one, so I don't know about parts being the same as the 250. :)

[EzyRider]

I'm and Englishman through n through! :)

Well the bike is now booked in for an MOT first week in Jan so will get the guy to have a look over and see what he thinks of it and go from there!

Cheers for the help :)

[Gz Rider]

...

[Water Warrior 2]

I'm and Englishman through n through! :)

Well the bike is now booked in for an MOT first week in Jan so will get the guy to have a look over and see what he thinks of it and go from there!

Cheers for the help :)
Sounds like a good start to determining the condition of the chain and sprockets.

I would suspect the 125 and 250 have the same gearing and parts for more economical and manufacturing ease. The 250 has about 18/19 HP so the 125 would make 10 HP at most. I would be sticking with the stock gear ratios as I think Suzuki has a good idea about that.

12.57 in = 31.93 cm.

Sunstar make most if not all OEM sprockets for Japanese bikes. If you do need new parts don't worry about the Sunstar quality if the package says Sunstar instead of Suzuki.
Front sprockets should always be made of steel although some rear sprockets can be aluminum because they do not wear as fast as the front. Stick with steel, it is cheaper.
Chain choice is O-ring or X-Ring. O-Ring is OEM and will work well. X-Ring is a bit superior but don't bother unless you can get it for the same price or a small difference .

Now we can wait till after the MOT and then start all over again with good/bad news to work with. :lol: :lol:

[EzyRider]

The 250 has about 18/19 HP so the 125 would make 10 HP at most. I would be sticking with the stock gear ratios as I think Suzuki has a good idea about that.


That's surprising about the 250, the 125 has 14.9 horses (or something along those lines) if I remember correctly...



Now we can wait till after the MOT and then start all over again with good/bad news to work with. :lol: :lol:

It's going to be a bit like that I think...Though I'm hoping it wont be too bad as it's the bikes first MOT.
I haven't noticed the rear sprocket looking particularly bad, but then haven't really looked that hard at it. I might just do it as a set, then I know it's all good. That and an oil change at the least after it's MOT n she will be much happier.
Has felt a lot smoother after oiling the chain last weekend!
Getting my brother to knock up a pair of those axle stands I've seen on here over the xmas break then it will be tinkering time again :)

[mrlmd1]

How many miles are on the bike and why do you think the chain and both sprockets need replacing?
Has the chain been cleaned and properly oiled? Did you measure it to see it has stretched beyond it's recommended length? Surface rust, if it has been dry, is not necessarily a reason to replace a chain. If the sprockets are not worn, they don't have to be replaced either. Have someone who knows something about bikes look at it first, you may be wasting your time and your money.

[Gz Rider]

...

[rynr]

sprockets and chain are different in GZ125 than 250

sprockets (for example JT sprockets): JTF410.15 and JTR1794.45
chain: DID428D132 - you can use standard or o-ring chain, using x-ring chain is not needed in bike that has 10 hp :)

[PimpS]

Hello guys!

So, could anyone tell me what chain do i need to buy for my gz250? The guy in a store. told me that i don't need x ring, and that the chain for gz125 fits my gz250? Hmmm...
I believe him for x ring - no need for, since bike has only 20 hp, but the chain and sprockets?

Thanks!

PimpS

[alantf]

The chain for the 250 is a size 520, with 110 links.

If your English is good enough, you can use the "search" facility, and you'll probably find all you need to know. :)

[Water Warrior 2]

The X-ring chain is better no matter what the HP. It is all about the chain having sealed in lubrication and the length of time it will last. The internal pins are always lubed and dirt, grim sealed out. Internal pins are the reason for chain stretch as they wear.

[rynr]

Also X-Ring chains are expensive. Performance/price comparsion is worth thinking for a while, but if money isn't a problem go get x-ring :)

[Water Warrior 2]

Also X-Ring chains are expensive. Performance/price comparsion is worth thinking for a while, but if money isn't a problem go get x-ring :)
Consider chain maintenance and how often you have to replace a cheap chain. Not worth it to me.

If you do want to have a cheap chain then you might want to invest in a chain oiler. There is a British chain oiler that works very well and is not that much money. Some Vstrom riders use them and get remarkable life out of a chain. I'll think of the product name after I finish typing and hit submit. LOL.



Got it. Loobman chain oilers. Hope that is the correct spelling. Google is your friend.

[plodder-exup]

Hi. I'm looking at a bodged chain change on a GZ125 for the friend of a neighbour, so I've got no manual or experience with these bikes.

The front sprocket washer is missing and I've got a new one but can't decide which way round it should go.

If the edge taper points inwards towards the sprocket then I can tighten the nut and it will compress and hold the sprocket firmly. My doubt with this is that the splines on the sprocket line up with the washer and will not become alligned until there is some tension on the nut and the tapered edge of the washer begins to be compressed.

If the edge taper points outwards then I would treat it like a locking washer and flatten it onto the nut. But this approach would mean that there is play in the front sprocket and this is what I think he has a problem with, as he thinks the gearbox is whining and damaged.

So to me neither of these seem right and I want to do this right, so could anyone please clarify this so I can get the man back on the road and the bike out of my (already cluttered) garage. I'm not a mechanical halfwit but I've got big Yamahas and have never owned a Suzuki (maybe I shouldn't say that on a Suzuki site).

Thanks
Lee

[blaine]

Taper points outward & gets flattened against the nut to keep it from loosing.Is there "play" in the sprocket or in the output shaft?

:cool: :)

[plodder-exup]

The play is in the sprocket. There was no washer before and the nut was tightened agains the splines of the shaft, leaving about 2mm of end-float between the nut and the sprocket.

The locking washer is about 1mm thick, so there's still about 1mm of end float. I can't believe that the nut is supposed to tighten against the splines; it just seems wrong.

On my FZRs, the retaining nut has a collar, so that it tightens against the sprocket, whereas the one on the GZ is a plain nut. I could fit a plain spacer washer between the locking washer and the nut to remove the play but there is not one shown on the parts diagram. I'm assuming here of course that I have the right nut and not one from the bodger's box of bits.

[blaine]

I can't remember as my G.Z. is gone.But that nut don't sound right.Some one will step in & verify if you have the wrong nut.
:cool: :)

[plodder-exup]

So would you agree that the sprocket should be clamped tightly between the flat face of the output shaft and the nut?

My thought at the moment is to get/make a spacer washer to suit and have him order the right nut in his own time.

[alantf]

If you download the parts manual, from this site, page 17 shows the parts you need.

[blaine]

So would you agree that the sprocket should be clamped tightly between the flat face of the output shaft and the nut?

Yep I would!! :) :2tup:

[plodder-exup]

I've got he right number of parts but can't tell if it's the right nut, so in lieu of having the right nut, I made a spacer washer, fitted it between the Suzuki locking washer and the but, torqued it all up tight and flattened the Suzuki locking washer onto the nut.

I'll let the guy know what I've done and recommend that he looks at getting the right nut but what I've done will be fine and get him back on the road.

Thanks for your help.