Identifying noise - Does this sound bad to You ?

[boksaman]

All right, i'm in process of ordering all service parts + belt & spring - will post all work i do on scooter in pictures & video..

@mousejunks i believe also that the belt is riding too low 

@Ruffus i'm cheap bastard but ill try to get original part

thanks everybody !

[john grinsel]

My experience with now 30 years and 400,000 miles with rubber band drive maxiscooters---all parts need to be exact OEM and in good condition and not worn out to work right, period.  There is no cheap way around drive belts!

[boksaman]

Couple of updates while waiting on belt - coronavirus situation made harder getting the OEM belt for scoot so i was busy tinkering around the bike:

- changed the oil filter and engine oil (IPONE 4T Scoot 4 10W40)

- changed the transmission oil (IPONE Trans 4 80W90 1L)

- changed air filter (OEM 17211-LEA7-E00)

- changed the spark plug (for DENSO Iridium: IU22)

one thing i noticed is that this bike had petrol in airbox - looks like not much but still worries me, got me thinking that my dirty engine is indicating oil/fuel/coolant leak somewhere

what are your opinions on this situation ?
can i wash the engine with pressure washer (to expose leak spot) ? will that damage electrical components etc .. how does one wash engine on scooter ?

[CROSSBOLT]

Been gunkin' and pressure washing several Kymcos and no electrical problems. Did get water in the cable release seat latch cables and had to rebuild them.

[Iahawk]

how I've cleaned my engine? - a bottle of your favorite detail spray, general purpose cleaner or degreaser and a few old microfiber towels...
spray and wipe off / clean a section at a time. It will eventually look like new.

[Ruffus]

Cleaned scooter and bycicles with BBQ or oven foam spray, just sprayed it on - let it work in, took a long handle painters-brush and helped where necessary, then flushed with garden hose.

[boksaman]

Used contact cleaner that leaves protective film around electrical contacts, then pressure washed the engine - i can say i'm happy with results

can throttle body have leaks ? on the picture before cleaning, gunk and dirt is all the way on the top of engine - so logically thinking whatever the leak is coming from must be from the highest point in engine bay

[Iahawk]

now that's my kind of clean engine! Nice job. About the leak - I wouldn't necessarily assume the leak follows gravity. It's possible for certain leaks to spread around...but with a clean motor you'll now have a better chance of locating the leak.

I'm starting to sound like a broken record but the mess in your airbox...make sure your gear oil isn't overfilled as many of our scoots vent the gearbox into the airbox and will soak the filter if overfilled.

[boksaman]

Quick update

Keeping myself busy while waiting on replacement belt to arrive, OEM belt or branded belts are harder to find in my country in this moment because coronavirus situation, so i have ordered that cheap belt from china just until i can find the better option.

I have painted scratches on exhaust cover in the meantime

 
i have also done valve clearance and it has made engine work much smoother - really happy about that

@ Iahawk i have looked into airbox and i think everything is all right with gear oil - it is not venting and soaking the air filter, thanks for the suggestion


I'm in process of buying manometer to test the engine compression - what kind of values should i expect?
In cyclepedia manual i have this values:

does that mean that i should get the reading around 228 psi ?

[boksaman]

One more question - does this part of engine suppose to have oil in it on Downtown 300i?

Have done some research regarding the leak mentioned earlier, preliminary inspection shows that leak is happening somewhere underneath starter motor.. people say that oil can escape from place marked on picture - but i'm not sure what model of bike they are talking about ..

thanks in advance


edit: after some research i realized that generator has oil in it, and hopefully some silicone around the place where electrical cables go out of generator housing will stop the leak

yellow - puddle of fresh oil appears
blue - starter motor
green - electrical cables

[mousejunks]

One more question - does this part of engine suppose to have oil in it on Downtown 300i?

Have done some research regarding the leak mentioned earlier, preliminary inspection shows that leak is happening somewhere underneath starter motor.. people say that oil can escape from place marked on picture - but i'm not sure what model of bike they are talking about ..

thanks in advance


edit: after some research i realized that generator has oil in it, and hopefully some silicone around the place where electrical cables go out of generator housing will stop the leak

yellow - fresh oil appears
blue - starter motor
green - electrical cables

yellow

The black plastic block is the seal for the 3 stator wires (yellow) and the crankshaft position sensor wires. It's always soaked in oil and it is a common point of leakage as the plastic hardens over time.

[boksaman]

Quick update:

Finally had time and all tools to disassemble CVT, looks like the problem was not bad belt but weak contra spring - how do i know ?

I have stretched the spring by hand from 135mm to 155mm after reinstall there was minimum vibration and that "clapping/slapping" noise for first 45 minutes of riding - after that noise is coming back. I believe it is because spring lost its "power" or "push" - what i want to say it is weak (i don't know if it OEM to be honest).

Stretching can do so much until spring comes back to its normal operation.

Also i should note that i have installed lighter rollers from 15.5gr to 13.43gr and things changed dramatically! I believe that lighter rollers have counteracted to weak spring. Anyway i have ordered white and yellow malossi springs from ebay. When they arrive ill make sure to post pictures and results after change.

Pictures of whole process are attached, hopefully they help someone like this forum and youtube videos helped me.

Cheers!! Downtown 300i is a best bike !

https://imgur.com/gallery/CCnFjOR

[boksaman]

After a long waiting time for springs & belt, vacation on island of Thassos i have changed OM contra spring with malossi spring. I have ordered 2 springs - white and yellow, only difference between the two is the stiffness. After instal i decided to keep the yellow one because that flapping noise from belt is almost completely gone with the yellow one.

The belt i have received from aliexpress is out of spec, namely the width is not specified 2.53cm but 2.7cm, so i kept the OEM. What do you guys think, can this belt still be used?

For now i'm pretty happy with the results, bike is working much more smoothly it is not jerky like before and flapping sound can be only heard when completely stopping only "tap tap" somewhat quieter for a second - not like before when it flapped any time when lowering the speed to 10-15km/h like "tap tap tap tap tap tap"

Hope this helps someone in future