How to properly clean your scooter's transmission/CVT filter (with photos)

[mousejunks]

As we know, the vast majority of scooter CVTs/transmission have a cooling system. The front drive pulley has a centrifugal fan (the fins) that sucks in air through an intake - basically a hole in the transmission cover. Hot air is pushed out through to a vent in the back or bottom of the CVT cover, cooling the pulleys, clutch and belt to prevent damage from overheating.

In some scooters, the cooling intake is covered with a filter. Not all models have CVT filters, such as the Downtown 300 which either has no filter or a rudimentary mesh filter, compared to the Downtown 350 which has a foam filter. This filter protects the CVT from rocks and debris but also needs to provide good airflow for cooling.

Here are the steps to clean your CVT filter.

1) Remove the filter from the transmission.

[mousejunks]

2) Soak the filter in warm water and detergent. This will clean out most of the dirt.

[mousejunks]

3) Cut open the plastic tabs holding the filter then pry it apart with a screwdriver.

[mousejunks]

4) Separate the foam from the plastic shell. The foam should now be easy to clean with detergent and hot water.

[mousejunks]

6) Wash, dry and reassemble.

[mousejunks]

7) Buy a new filter.

[Ruffus]

Mouse 👍nice write up!
But why to go through 1) - 6) just to buy a new filter afterwards.....?



Ok, it's a joke😉

[Ruffus]

Mouse, interesting subject!
In certain scooters, particularely aircooled models, CVT surface temperature goes, being a part and close of this scooters motor structure, up to 100°C.
Not in cold/freezing environment but here in Italy during hot summers, and for sure overseas too.

So I came a couple of years ago to the idea to remove air INTAKE hose (putting a mesh) and modify the metal CVT outer casing by removing some dividing "walls" within this casing and open additionally three holes in front and several air OUTLETS in the rear. (pls see pics)

Result:
never had more than 70°C on this casing anymore
Plus:
-dust and heat dissabates more quickly from CVT
-in this case my CVT casing is cleaned regularely by waterhose (moderate pressure) through INTAKE mesh.

Minus (could be): by usage offroad and dusty/ gravelly environment entering of unwanted debris, but didn't experience that.

[mousejunks]

Mouse, interesting subject!
In certain scooters, particularely aircooled models, CVT surface temperature goes, being a part and close of this scooters motor structure, up to 100°C.
Not in cold/freezing environment but here in Italy during hot summers, and for sure overseas too.

So I came a couple of years ago to the idea to remove air INTAKE hose (putting a mesh) and modify the metal CVT outer casing by removing some dividing "walls" within this casing and open additionally three holes in front and several air OUTLETS in the rear. (pls see pics)

Result:
never had more than 70°C on this casing anymore
Plus:
-dust and heat dissabates more quickly from CVT
-in this case my CVT casing is cleaned regularely by waterhose (moderate pressure) through INTAKE mesh.

Minus (could be): by usage offroad and dusty/ gravelly environment entering of unwanted debris, but didn't experience that.

Yes there is a significant amount of heat that comes from the engine block and rear wheel as well that can't be explained by the friction between the pulleys and the belt or clutch and the clutch bell.

That looks like quite a good modification. Surprised the manufacturer basically sealed the transmission in the first place.

[Ruffus]

Well, has its plusses and it minusses but I guess it's more on the plus side.

On our Xcitings airflow is even worse. There is a cover above the metal casing which is functionally an engine part with being connected by a support boss and bearing. I have to think this over on my 500 to improve ventilation without too many disadvantages.

[mousejunks]

Well, has its plusses and it minusses but I guess it's more on the plus side.

On our Xcitings airflow is even worse. There is a cover above the metal casing which is functionally an engine part with being connected by a support boss and bearing. I have to think this over on my 500 to improve ventilation without too many disadvantages.

Well that's a stupid design on Kymco's part.

I'm thinking a holesaw or angle grinder would do the trick. Then attach something like this computer fan filter with tapped screw holes to mount.

[CROSSBOLT]

Good article with good pictures!

I have had the DT300i foam filters blow out after a few thousand miles so devised a composite screen to replace the foam. I reasoned since there was no real downside of riding with a blown-out filter there would be even less downside with a bug/rock screen.

[Ruffus]

Good article with good pictures!

I have had the DT300i foam filters blow out after a few thousand miles so devised a composite screen to replace the foam. I reasoned since there was no real downside of riding with a blown-out filter there would be even less downside with a bug/rock screen.

@CROSSBOLT, did you mount this outer plastic cover again after this screen intervention?

[CROSSBOLT]

@CROSSBOLT, did you mount this outer plastic cover again after this screen intervention?

I pried the plastic frame apart and ditched what was left of the foam filter sheet. Then cut .25" squares screen and bug screen (.062" squares) to fit in where the foam was before. Sandwiched the screens between the plastic carrier halves and remounted with the stiffer .25" screen to the inside.

[mousejunks]

Good article with good pictures!

I have had the DT300i foam filters blow out after a few thousand miles so devised a composite screen to replace the foam. I reasoned since there was no real downside of riding with a blown-out filter there would be even less downside with a bug/rock screen.

That's a neat job. My own DT300i didn't even come with filters or any mounting holes for one.

It turns out there are two versions of the filters for the DT300i, the flat one (11350-LEA7-E00) and the dome-style one (11350-LEA7-E02).