How to: Change your belt with no expensive tools!

[tstalion79]

I am not the type that likes to spend money on things, so when it came to changin my belt I was annoyed that I would need either a special 'holder' tool and an impact wrench to get the job done.  After staring at the transmission for a couple hours scratching my head, I did some research and figured out how to do the whole job with a plane old socket wrench and $15 dollars worth of stuff from lowes.  So, here's how to do it.  You will need:

A socket wrench
3 feet of nylon rope (I used 3/8 inch)
1 strap wrench http://www.lowes.com/lowes/lkn?action=productDetail&productId=253674-16878-50540

First, remove the variator nut.  To lock it in place, remove the spark plug and turn the nut counter clockwise until your piston is almost at top dead center.  This is important, as you don't want the rope getting in any of the ports in the sleeve.  Now, feed as much of the rope as you can into the spark plug hole.  I was able to get about 2 feet of it in there.  This will lock your piston in place, and the soft nylon rope will do no damage to the piston.

Now, crank that nut off.  It takes some force, but I was able to do it after about a minute of tugging.  There you go, variator comes right off.

Now, to remove the clutch, take your strap wrench and clamp it around the clutch bell/clutch outer/whatever you call it.  Again, crank the nut off.  This, too, took a little bit of tugging and force, but just takes a few minutes.  Now you have your clutch nut off, and the whole assembly will come right off. 

To put everything back on, it's just the whole process in reverse.  Remember to TAKE THE ROPE OUT OF THE ENGINE before tightening it again.  Bring the piston to almost top dead center by turning the crank clockwise, and then re-insert the rope to lock the piston before tightening it. 

Bam.  No impact wrench, special holding tool, or anything else needed!  If you are concerned with the whole putting a piece of rope in your engine thing, do some research; it's been done for a hundred years, and does NOT damage your engine as long as you get your piston to almost TDC. 

Ted

[Areomyst]

Instead of a holder tool, you can also put a bit of nylon rope down into the spark plug hole (recommended only on 2-strokes as there's no valves to get tangled with).  Rotate the engine till the piston squishes the rope between itself and the head, then you have the engine locked so the crank doesn't turn while you take the nut off.

The strap wrenches work great.  I don't use them, because I have the "expensive tools" (actually only paid $100 for the 1960-something era air compressor).  A chain wrench works sort of like a vice-grip with a chain you can wrap around things.  That works awesome for the clutch bell.

~Josh

[axy]

How do you lock 4-stroke engine?

I am asking because change of belt is due soon on my Agility 125 4stroke.

Sorry if the question is stupid.

[chubbyrockstar]

Not a dumb question Axy, from my experience on 50cc 4 stroke i have done it this way when i didnt have an impact wrench around...
but it is much safer trying to rent an electric impact so you dont do damage.

remove the fan shroud and fan from the other side of the motor,then find two bolts to fit in the pulley holes behind the fan. do NOT screw these bolts in all the way because you will crush the coils on your stator. (found this out today the hard way and ive even done it a few times) just screw them in far enough to where you can wedge a screwdriver in between the bolts as the pulley turns a tad. Also make sure you have them in at least far enough that you dont strip the threads out but not far enouh to even come close to the coils inside.
then on the other side of the motor remove the nut to the pulley your trying to loosen, sometimes the screwdriver slips out between the bolts so be careful.

an impact is really the best option because you dont have to lock the motor..but if you want to try this way i hope you get the concept of what im trying to describe.

[blue]

my agillty 50 will sometimes start hard .when going to start nothing happens Ill play with the kill switch a few times. no lights or anything. turn the key a few times. then after that it might start.sometimes not. could it be a short .

[chubbyrockstar]

blue,
 it sure could be a short or a loose ground somewhere, check out the little ignition power wire that tightens with the power wire to the batery, that little wire sometimes need to be played with sometimes on one of my 4 strokes and it sounds like what your going through.
might not be that but its worth a shot.

[axy]

For some reason I think when I try this in real life, I will have quite a story to tell.
Thanks for the tips!

[Areomyst]

You can use the rope trick on 4-strokes also, but you have to make sure that you're compressing the rope on the compression stroke of the engine, so that both valves will be closed.  It's just harder to do on the 4 strokes because the spark plug hole is so much smaller.

There are Honda tools out there that are designed to hold the flywheel.  You can also make a tool by getting a piece of steel and cutting an old starter bendix in half, then welding the half bendix to the steel plate and drill holes in the plate.  The holes and bendix half will be aligned in such a manner so that when bolted to the engine (with CVT cover off) the bendix half will block the pulley half from moving.

Lots of Honda stuff works with our scooters, as both Kymco and SYM built a LOT of Honda's stuff.

~Josh

[wordslinger]

..Agility 50..4 stroke...I made the tools for the clutch...used a pair of Vise-Grip vise clamps and a block of wood to hold the variator sprocket...

peace

.

[Ybslow]

Here's a helpful hint.  I have to change the counter sprocket on my race bike somewhat often.  I have niether an electric or air powered impact wrench.  What I (we) do is use a hollow metal pole as leverage.  About 6 foot is good.  Go slow and it'll come right off.    When we put it back on, we hand tighten it and bend the nut lock over and usually from there on out it's easy to take on and off.