Sorry for a newbie qestion...

There's no reason to apologize, if anything such assistance is part of the point of this forum after all lol

While you can ofc simply replace the broken link with a master, it would be better to invest in a chain breaking tool as then you're able to fabricate any length of chain you wish. While there are many types of chain breakers, I prefer the following style as it seems far more capable of dealing with a wider variety of chain as well as being durable: Amazon.com: MOTORCYCLE DIRT BIKE ATV CHAIN LINK BREAKER TOOL: Automotive

As for the chin itself, the kit supplied chains are renowned for being of an extremely low quality. The 415 is often replaced with a #41 roller chain which is slightly wider but has the same pitch. It can be found at almost any farm & tractor supply or a decent hardware store for roughly $10 for 10' for the generic "heavy duty": Amazon.com: Roller Chain: Everything Else

Here's a handy chain chart in case you need it;
Azusa Engineering, Inc. Online Catalog - Roller Chain, Motorcycles, etc.


Welcome to the forum BTW

i like the kmc 415 chains, they hold up well and are a reasonable price. well suited for what we're doing from what iv'e seen.

also that chart barelyawake posted is great, hadn't seen that before.

Ya know, I'm wondering why a 415 chain broke. Before you put another chain on there, I would check your allignment fore to aft. Check the caster and camber of your rear wheel too, it should be bolted straight up and down, and pointing straight in line with the frame. You may want to see if your engine is tilted at all. And is there anything behind that little sprocket cover that might have gotten stuck in your chain?


I'm one of the more anal-retentive people here, I'm sure, so if that sort of thing happened to me I'd come up with a "laundry list" of things to check. But, hey, it keeps me out of jams sometimes.

Unfortunatly this is one of the few things that's really hard to tell w/just pics as perspective gets a lil weird w/such ...but ofc we love pics here so post 'em ifn ya got 'em lol

There's a couple few ways to check chain alignment, checking for chafe/wear on the inside of the engine's sprocket cover is a good start - but two of my faves are hunkerin' down behind the bike and sighting down the rear sprocket to the engine's sprocket (like a rifle's sights) looking for twists or misalignment, another way is to suspend the bike so the rear wheel is off the ground and slowly spin the rear wheel while watching the sprockets teeth as they protrude through the chain - ideally they'll be in the middle of the chain at both the top and bottom of the sprocket. If they're all to one side your sprocket is too far in or out and/or not aligned with the engine's, if they're on one side at the bottom and the other at the top yer wheel may be crooked in the bike, if the teeth "wander" from side to side as you slowly spin the wheel the sprocket itself is not true with the wheel.

You can also take a long straight edge (like a contractor's level) and place it flush on the side of the engine (sprocket & mag covers and/or clutch cover) and towards the rear of the bike - sighting along it to see if the engine isn't "twisted" in the frame. Don't take it too seriously as the covers aren't exactly true lol, but comparing the difference between the two sides outa give you an idea if it's really bad or not

Allen Wrench is defo right about lookin' for causes, somethin' is defo a bit wonky - but if everythin' seems true enough, there's also the chance ya just got a bum chain. I got a kit chain one time where the rollers were only 1/2 as wide as they should have been, leaving the link pins partially exposed In alla my years of tinkerin' I'd never seen such an example of poor quality control lol

Soft mounting these particular lil motors as proven to be a problem, with broken mounts & movement not uncommon - it's prolly best if you remount yer engine w/o the squishy bits: http://motorbicycling.com/f6/rubber-mounts-19205.html

BarelyAWake said:

Soft mounting these particular lil motors as proven to be a problem, with broken mounts & movement not uncommon - it's prolly best if you remount yer engine w/o the squishy bits: http://motorbicycling.com/f6/rubber-mounts-19205.html

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what do you think about cork? like cork wrapping tape used on handle bars? that's what i was considering using to fill space on my mounts, cork is known to stop vibrations pretty well but i'm not sure how much that applies to what we're doing.

2door said:

Any resilient material between the engine and the bike frame does not eliminate vibrations which are common to a 2 cycle, single cylinder engine. The soft mounts will only transfer the vibrations to the fasteners [& exacerbate mount/motor movement]. This is where so many people get into trouble with broken studs and such. Mount the engine as solid to the frame as you can get it with good contact area throughout the mounting surfaces. Yes, the inherent vibrations will then be transferred to the frame where you'll feel it but you'll benefit from longer fastener life and other parts that will be effected by a soft mounted engine. This isn't theory but has been proven time and again by many builders.
Tom

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^ sorry, it's far easier to C&P Tom's well phrased post than to type it again lol

BarelyAWake said:

^ sorry, it's far easier to C&P Tom's well phrased post than to type it again lol

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ok so corks probably better then inner tube but still not a good idea, what's the best solution for mounting to a frame thats frame tubes are slightly smaller then the motor mounts?

my bikes frame doesn't quite fill out the shape of the mounts enough for my preferences.

Shims made frm aluminum cans come to mind, aluminum conduit/pipe/tubing if the can material isn't thick enough - aluminum is awesome for many reasons, being easy to work w/just basic hand tools is ofc one of 'em

BarelyAWake said:

Shims made frm aluminum cans come to mind, aluminum conduit/pipe/tubing if the can material isn't thick enough - aluminum is awesome for many reasons, being easy to work w/just basic hand tools is ofc one of 'em

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ok thanks for ideas/info barely.