Yamaha yq50 aerox 2007 crankcase gasket?

[mog9166]

Hi, please bear with me on this bike (no, I wouldn't call it that either!)
My son hasn't a clue, '', so it's mother here. I do know the basics and i'm not completely engine illiterate but i'm no mechanic. Want to prove I'm not stupid and shut him up
For some reason, I haven't got to that yet, the electric start works when it wants to, so its relying on the kick. This had rounded off so got a new one but the shaft had rounded as well so I've fitted a new one of those. It's inside the crank case. It's all very dry and a bit rusty with a white dust and inside the case itself looks 'pitted'. (the dust looks like cigarette ash). Can I oil or grease anything in there? I noticed when taking it apart there is a gasket, can you tell me what this is for because there is nothing in there to seal up and hold in, or should there be? and what happens if you don't put a new one on?

Also at the back of the crankcase near the rear wheel is what looks like an oil cap. It does have oil written to the side of it. On inspection theres very little, if anything, in there. I'm thinking it should be transmission oil, if it is, what and how much do I put in? I will be gratefull for any help that anyone has to offer and remember...please keep it simple...thank you

This bike has been going until we were unable to kick it anymore, but it really needs work on it. I just want to get this bit done for starters. I'll be back for the rest!
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Maria

[Robby]

There should be some oil in the final drive, but quite a small amount. Worth getting a workshop manual for specific amounts, I would expect it to be around 100ml. Certainly not brimming. Have a look for a drain plug underneath, drain, and refill with the correct amount. Normal 10W40 engine oil will do the job.

I believe the engine is a 2 stroke, so does not have a sump or contain any engine oil - the 2 stroke oil lubricates the engine, and scooter gearboxes run dry.

The white dust inside the crank case (belt case?) is likely to be the powder residue from aluminium alloy corroding. Not something to worry about, I would probably clean it up for peace of mind.

I'm more interested in the electric start not working. Scooter kickstarts are notoriously weak and only there for occasional/emergency use. If the starter just clicks when you press the button, you have a knackered battery. Try charging it, or replace. Be sure to charge the replacement battery before fitting.

[davebike]

I think the bit you working on is under the belt cover
It is "dry" in there and in fact should be vented it is often very dusty and corroded in there

Transmission oil is 130cc of 10/30 engine oil but any engine type oil will be fine

Dave
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Dave
NC750Xdct + others at work !
[email protected]

[mog9166]

Thank you. I wondered why couldnt find where the engine oil went! lol Years ago I had DT 125 that was 4 stroke so this is all new to me (i'm learning backwards)

Yes I think it needs a new battery, so thats next.

Regarding the gasket...does it need it?
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Maria

[mog9166]

Yes I would agree its the belt cover. Tried everyone for a battery charger-no luck. So it will have to wait till pay day for a charger or battery or both. And i need oil for the car so I can pinch a bit of that.

Still the question of the gasket?
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Maria

[Robby]

It doesn't sit in an oil bath, so the gasket is there to keep dust and crap in, and keep water out. Worth having it in place.

What happens when you press the button for the electric start?

[mog9166]

When he 1st got it nothing,but he fiddled with the battery wires and it turned over but now is flat. I presume it charges like a car one does unless thats broke as well. As it is I've goto sort out the indicators as switch came off in his hand., theres a sponge where the air intake is and it looks like it needs a tube of some sort, good job its under cover cause the rain gets in there. Nice little 'project' he's bought, Good job I like a challenge.
I've downloaded the service manual for the older version (cause that was free) but I'm finding it hard to find what bits what with so many bits broken, mended and made do.

Oh THANK YOU, you made my day btw My sons mate, who knows "everything about these bikes" has told him that it will seize if he tries starting it without it!
lol I knew it must be there for a reason but as its not holding any oil in it wont be a problem trying to kick it over. I will put the old one back on. Don't worry I've told him if his mate knows best get him to fix it!
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Maria

[Robby]

The alternator will charge the battery, but at a very low rate. It will have trouble recovering a deeply discharged battery, and would take over an hour's riding to put much charge into a healthy battery.

You need to get that battery on a proper battery charger like an optimate and leave it overnight. With luck it will show some green lights after a while.

[Shaft]

[mog9166]

Sorry, Yes it was 2 stroke come to think of it...but i didn't have to mix the oil/petrol manually, i had a little 'tank' i filled up and it mixed automaticly. It was along time ago. But there was the engine oil as well, with a dipstick and a drain plug underneath....you got me thinking now! There was def 2 sorts of oil.

Sorry not been back on all week, got a bit fed up with my sons negative attitude and lack of help. Eventually he borrowed a charger, but although bubbled well the needle hardly moved. He decided to try it anyway and it turned over lovely but wont start, nota splutter, needless to say battery back on charge. Thats where we're up to.
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Maria

[mog9166]

right I'm back.
Me and my son had a fall out over this, but as its just being left I thought I'd carry on.
Connected a lovely charged battery, but havnt got round to seeing if it will start because once the battery is connected she starts turning over and no matter what you do you cant turn it off!!
HELP again please
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Maria

[Robby]

That points at a knackered starter solenoid - basically a big relay. It's stuck close, which is unusual. It may be possible to take it apart and clean it, but they are a cheap part, and you would probably get away with fitting a generic one off ebay.

To find it, follow the thick red wire from the battery until it goes into a little box. That is the relay. Will also be one or two small wires connected, which deliver the signal to the relay from the starter button on the handlebars.

[mog9166]

If its really near the battery then I know where your on about. Thanx Ill give that a try.
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Maria

[mog9166]

Right I'm back. I've left it for a bit cause it was too bl**dy cold to keep going out to it.
Had some progress....got fully charged battery, which I can connect now without it turning over....I turn the key pull the lever, press the button and she turns over lovely.....but thats it. I've checked the spark plug and it looks ok, 22 gap and it sparks. Found the carb and the petrol is getting to it but I cant say through it.....how do I check that? (god I thought I knew all this, but the little grey cells have let me down) and what's next to check?
I'm appreciating all your help
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Maria

[Dave M]

What else is wrong with it?

[mog9166]

still wont start
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Maria

[Robby]

If fuel is getting to the carb, you can assume that fuel is getting through the carb. Petrol is itself a very good carb cleaner, so as long as a bike is used fairly regularly then the carb will stay clean. They only get dirty after standing for a very long time (over a year), or if dirt enters the system. It can either do this by getting into the fuel tank (difficult) or a metal fuel tank rusting (common, but unlikely in this case. You may even have a plastic fuel tank).

So, to be sure:
1. You have fuel in the tank.
2. The engine is cranking over on the starter.
3. The spark plug is sparking.

Those are the ingredients needed to start an engine. This means you may well have a problem with the engine. Was it starting before?

If it was starting before, then just try cranking it until the battery goes flat. Sometimes it can just take several minutes of cranking to persuade a motor to start. I have ignored this in the past and tried taking things apart to try and fix them, when all it needed was a bit more cranking for the first start.

If that doesn't work, then I would start by changing the spark plug. A plug that works outside the engine doesn't necessarily work inside the engine, and it's quick, cheap and easy to change.

After that I would be looking at fuelling or compression.

Fuelling- has the scooter been "tuned" in the past - modifications to the carb or exhaust. If the carb has been messed with, I would look to put the mixture screw back to standard. You will need a workshop manual to identify which screw, and the correct setting, which is likely to be around 2 turns out from screwed all the way in. This screw only controls the fuel/air mix at idle, so adjustments to it will not affect the running of the engine when under load.

Compression - the way to test this is using a compression tester. We'll come to it after the other things have been eliminated, it requires the use of a special tool, someone local to you on this forum will have one and know how to use it.

[mog9166]

Yes it was working fine when my son bought it, other than the electric ignition didnt work, it had to be kicked. But after 2 kick start pedals and a new gear (cause I know they are not made for excessive use) it was time to sort out the battery etc. Its since the new gear was put in. Now I'm waiting on a new pedal, so new teeth on both bits, before I'm going to attempt to kick her over, fed up with 1 step forward 2 back.
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Maria