General help me on this scooter thread please

[loicloicloicloic]

So I am repairing this scooter (keeway hurricane) that my girlfriend has been wanting to sell for the past year. It ran a few months ago after having been sitting for like 2 years (cleaned carb did it), then the keys were lost etc etc.
Long story short it won't start now, with carb cleaned and petcock replaced. (old one failed open)
Did a compression test, woops, 105 psi. Dropped some oil in the head, then read 120 psi.
So I figured the rings were bad.
Took out the piston, checked the rings end clearance and piston to ring clearance with a feeler gauge, they are WELL within specifications, so I figured the rings are fine.
Next up is the base gasket which might really just have ripped when I pulled the cylinder out, but I will replace it anyway.

Last thing I want to check is the reed valve...the keeway manual says you can get to it without having to take the engine off the frame, but either it is a gross lie or I am missing something...there are 4 bolts, 3 of which are accessible, and one which is plainly under a part of the frame and impossible to access.
Am I missing something?

I am far from an experienced scoot mechanic but I have done my homework...can someone enlighten me? Should I change the rings even if they are well with specs? The old petcock had failed and gas flew into the vacuum tube and possibly down the crankcase, could that explain why it wouldn't start now (that was months ago and the piston moves so there is no "lock up")?
Or is it really just because of low compression (105 psi isnt enough, right?)

Somebody heeeellllp

and thank you

[wile]

Yep the compression is to low at least 120psi. Are you sure you checked the compression correctly with the throttle wide open to allow as much air in as possible. Otherwise you will get a low reading.
Wile

[loicloicloicloic]

Mmmh now that I think of it I am not so sure I did that both times...I will try again
Is it unusual for rings to be in very good condition after 10 000 km with no servicing???

[wile]

Yes, 10,000KM is only little over 6000 U.S miles If everything else was working as it should and being lubricated properly the rings should be fine. But as they say sh!t Happens so check the compression properly and see what the PSI is. Putting in a teaspoon of oil into the chamber will always give you higher compression. It is when you know you have low compression that helps determine whether its the rings or the valves are leaking, but in your case no valves.
Wile

[felliott]

Yes, You have to remove engine to check reeds on a keeway Hurricane. I have one and the motor mount bracket is in the way.

[loicloicloicloic]

Holy moly I just found out that the exhaust gasket is missing. Probably why the compression was bad?

Now I see on the internet that there is the copper ring type of gasket and the other type (attached picture)
which one is the correct type for this scooter?
Thanks

Attachments:

[gregw]

I'm not sure about what type of gasket you need, but a missing gasket won't effect a compression test... (test always done with throttle wide open)

[loicloicloicloic]

dang...guess I got to check the valve after all. It still wont start at this point...
but surely having massive quantities of air leaking out of the exhaust gasket could prevent it from starting up?

[wile]

If it is leaking pretty bad where the Flange attaches to the motor it will have a hard time starting. It is sucking in to much air.
Wile

[james03x1]

It looks like serious problem i think you should find a expert mechanic and get repaired.

[martyd]

Have you checked the spark plug and made sure you were getting gas to the carb ?

[jsuggs]

I would recomend checking the three things that every engine needs to run: Fuel, Compression, and Spark.

Is the carb getting fuel? The easiest way to tell is to remove the air filter housing, look and smell. How old is the fuel? A second less technical way is to remove the air filter and spray a little, I mean like 2 seconds, of break cleaner in the carb and crank it. If it tries to start or starts and dies, you have a fuel problem.

Do you have compression? To do a proper compression test hold the throtle wide open and using the starter(it turnes the engine much faster than you can kicking it), crank the engine over for 3 revolutions. The gauge will record the highest reading. Usually 10-15PSI low will not cause a engine not to start. It will cause rough idle, reduced power.

Do you have spark? Remove the plug and you can eather hold it against something with a good ground which is common, I wouldnt recomend it, I would use vice grips and clamp it to a good ground (clamp it on the hex flats so not to damage it) and see what kind of spark you have. I have seen more than one plug come from the box bad. They are one of the most delicate parts of the engine.

One more thing which is very important since it can afect the compression test and spark test. How charged is the battery?