fittting 15t front sprocket

[Robell]

I've changed the front sprocket twice, but never the rear.

Front's always wear faster, and while it's usually recommended to change both sprockets and the chain as a set, I haven't found it necessary.

[onazoomerF]

So, when I see this subject, I wonder what the specs are.

Like does the front sprocket have any lateral play, i.e. needs a "filler" washer to prevent "wobble"?

Since you've changed it a few times, did you notice that the higher number of teeth is best,

or were all yours the same number of teeth?

[Robell]

The first 15T sprocket I bought from JT, needed spacing, as it wasn't designed for the Inazuma
The second came from China and was direct fit and had the rubber insert fitted, like the original

I find the 15T is a far better option than the original 

[onazoomerF]

Thanks for this reply. I still may get my hands dirty by getting a bigger sprocket.

[xris_xcess]

Ottawa

I order my sprocket the other day. I work super semi-occasionally at a car dealer, one of the techs said he would help me avec an air gun.

It was sold in Canada as a GW250. Mine is a 2017 but purchased it brand new in April 2019.

Over 30k, any major maintenance you have done? Have you been following along with the maintenance schedule?

Follow the manual, no exceptions,
-Oil change every 5k km. New oil filter every 5k km (hiflo - great deal on ebay for a 3 pack).
-Valve clearance adjustment. Had to adjust twice. Makes a noticeble improvement on idle.
-Swapped factory chain at 15k km. kinked links. rather low milage. Installed DID zvmx x-ring (overkill... but massive discount on amazon.uk for last unit!)
-K&N air filter. Got a good bump in top end power 9k rpm (but... see next point)
-Recently changed fuel strainer (some call it the filter, before fuel pump in the tank). Was having two issues: Stalling when running low on fuel (one bar flashing), but still plenty to for another 40km. Also slight loss of power at top end (9k, 10k rpm). Was not dirty... but the inner material (black) seems to have "swollen" and was seriously restricting flow. Got a OEM equivalent replacement on Aliexpress.
I have removed the fuel assembly twice, and cleaned thorougly with carb cleaner. Seems to restore a bit of top end power. Debating if its the strainer, filter or pump. I also have to check/clean injectors just to be sure.

At some point I would like to hook it up to a SDS system (suzuki computer gadget, reads parameters off the bike computer, can do some special mantainance with it). Just to check there is nothing too "off". But not sure how much that would cost (you can buy one on ebay for about $200us). Local dealer should have one. Just a thought...

Overall I am 1000% pleased with this bike. Couldnt ask for more. First bike. Could have gone for a new, but smaller bike (150cc, 200cc), but I think I would have suffered on the long highway rides. Its been a workhorse, racking up kms like crazy. Solid, powerfull enough, easy to handle, overall cheaper parts/repairs (if you shop around...)

Hope I can hit such a good bike when I decide to upgrade

[Pickwick]

Sprocket installation:  I got the same 15T sprocket from AliExpress that most of you did.  It removed easily with an electric impact wrench; hardest part was getting the dowel pins free to get the sensor mounting cover off.  The nut reinstallation torque is similar to car lug nuts, and I wanted to be precise and use the torque wrench.  Since trying to turn the nut turns the rear wheel backwards, I stuck a shovel handle between a rear spoke and the bottom of the swingarm to stop the wheel turning.  Easy job.

Due to weather I haven't ridden yet with the new sprocket.

[clack]

I tried a 41 teeth rear sprocket. It costed some more than a front sprocket, but not so much: 30 euros shipped from the bay.
I chose it after making a lot of careful calculations about the primary, gearbox and secondary transmission ratios.
Now first gear lasts more than just three inches,  second and third have a way better reach out, like a true 250 cc., fourth gear is excellent for overtakes, fifth gear almost equals what the sixth was with the old rear sprocket and finally sixth gear is now more adapt for suburban roads, with the engine less strained, it revs some 1500 less at the same speed, about 90 kph, and is probably more durable.
Fuel consumption is of course reduced.

[onazoomerF]

clack

I tried a 41 teeth rear sprocket. It costed some more than a front sprocket, but not so much: 30 euros shipped from the bay.
I chose it after making a lot of careful calculations about the primary, gearbox and secondary transmission ratios.
Now first gear lasts more than just three inches,  second and third have a way better reach out, like a true 250 cc., fourth gear is excellent for overtakes, fifth gear almost equals what the sixth was with the old rear sprocket and finally sixth gear is now more adapt for suburban roads, with the engine less strained, it revs some 1500 less at the same speed, about 90 kph, and is probably more durable.
Fuel consumption is of course reduced.

WOW! Excellent report. You've given us 'real time' information. Thank you. Happy riding for 2023.

[clack]

Hello Interzoomer,
Thank you for appreciation.
Thanks to your calculations for the 1000 rpm speed, i've been able to calculate a speed of 15,235 kph in sixth gear. So, instead of 7000 rpm, an 80 kph speed, more or less equal to 55mph, is reached at 5250 rpm. The engine is way more relaxed and durable with less consumption.
I assumed that the Mitas Sport Force 140/70 r17 mounted on my Zuma has the same circumference as your Pirellis.

The best anyway, at least in my point of view, is what i described in the "Mods for my Inazuma" topic, here https://www.inazuma250.com/index.php/topic,2030.0.html.
The Zuma carburetion is so lean that the engine is visibly suffering for it. Of course performance does the same. Having it a bit richer makes the behaviour of the Zuma something completely different.