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Post by gingel on Apr 19, 2015 4:54:21 GMT -6
Hi,
I have a SYM scooter with a 125cc engine (air cooled).
I'm after an engine rebuild, and i also replaced the cam chain and the tensioner. A few days ago i finsihed the engine break in, and i checked the valves clearence, and i noticed that the cam chain have free play to the sides.
I turned the tensioner about a 1/4 of a turn counter clockwise, and i guess it made the chain more tensioned, and the free play is much less.
Is it a bad tensioner, or sometimes do you need to "help" the tensioner ?
Here is a video of the chain before i turned the tensioner: (you can hear the "tic" sound from the chain moving)
This is a video after i made the chain more tensioned:
Thank you for helping.
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Post by gingel on Mar 9, 2015 16:05:33 GMT -6
Thank you.
I hope the rest of the rebuild will be ok. :-)
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Post by gingel on Mar 8, 2015 14:21:39 GMT -6
Thank you for the answer. It is lucky that the threads are still ok.
Are you sure about putting oil on these bolts? In the manuals of several scooters, the only bolts they are saying to put oil on, are the 4 nuts for the head, and the 2 M6 bolts on the left side of the head.
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Post by gingel on Mar 8, 2015 5:36:47 GMT -6
Hello, I also asked this in the neighbor forum, but i thought i'll also ask here. I am at the end of a rebuild, and i installed the crankshaft on the left case, and put the right case on top of it. There are 2 M6 bolts that are for the right case, and the manual said to torque them to 1.5-2.0 kgf-m (around 15-20 Nm). Well, i torque it to 15Nm, and one of them started to break, and the other was also on his way to break. Luckily i was able to pull them out and the threads inside the case are ok. Is it too strong for an M6 bolt? I found a chart which says that M6 bolt in aluminum needs around 5 ft/lb (around 7Nm). What do you think is the correct torque for the M6 bolts? There are also the 2 M6 bolts on the left side of the engine head (where the timing). What is the correct torque for them? The manual is saying 1.0-1.4 kgf-m (around 10-14 Nm). Is it too much? Thank you for any help.
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Post by gingel on Jul 6, 2012 2:09:02 GMT -6
I tried to play with the air/fuel mixture when the old choke was inside, and it didn't help. Do you think that now with the other choke, it could do a difference? I'll try today or tomorrow, to see if it change something.
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Post by gingel on Jul 5, 2012 8:00:29 GMT -6
Yes, The first thing i checked. This cold start problem was from the day it was new, so this is how it is. But the starting problem after 20-30 min, started after i changed carburetor. so i guess it's because of the choke that came with it.
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Post by gingel on Jul 4, 2012 13:15:17 GMT -6
Ok,
I will keep inside the one that the scooter work with it best. Btw, i was quickly to say that is start up right away from completly cold engine. After the engine was cold after 10-12 hours, i still needed to give it a little throttle, but still it's starting more easy. The big difference is that i don't need to give it throttle after the engine was off for 20-30 mins.
Thank you.
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Post by gingel on Jul 3, 2012 7:13:41 GMT -6
I checked today the voltage to the choke, and it's 11.9-12.2 Volts AC. I didn't measure the plunger.
Regarding the starting, that's the strange thing. With the first choke (the one that extending less), i need to give it a little throttle so it will start from cold, and even 20-30 min after i shut down the engine.
With the second choke (the one that is extending more), the scooter fire up right away, no throttle needed, engine cold or hot.
Both of the chokes needles are at the same height when cold, so i really don't know what makes the scooter to start ok with one, and have some difficulty with the other.
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Post by gingel on Jul 2, 2012 16:16:57 GMT -6
How do you open the choke? (to replace the heater)
Is there a way to run in at 10 volts?
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Post by gingel on Jul 2, 2012 15:36:55 GMT -6
Can you see the difference between the two chokes i have? Does it look like the first one is not going all the way out?
Also, the second choke is extending in less than a minute. I installed it inside the carburetor, and at first the rpm is high, as it should, but after less then a minute it drops down, while with the first choke it's taking 2-3 minutes until rpm drops down.
Do i have bad chokes?
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Post by gingel on Jul 2, 2012 8:31:33 GMT -6
Hi, I checked the choke that came with the carburetor, and i think it may not extend enough, but it does retract back quickly. Here is a picture after the engine ran about 5 minutes: I have a spare choke, and i connected it to the wire harness, and let the engine run, and this choke extend very quickly, and retract back very slowly. After about 1 min of the engine running, the choke was like that: Are both of these choke malfunction, or only the first one (that came with the carburetor)? Many Thanks.
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Post by gingel on Jun 29, 2012 6:09:30 GMT -6
Ok, i'll try to do more wraps.
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Post by gingel on Jun 28, 2012 3:04:30 GMT -6
Yes. it wraps on the plug wire. I thought maybe a shielded wire may be the solution. what do you think?
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Post by gingel on Jun 27, 2012 15:21:42 GMT -6
Hi, I have this tachometer from ebay : www.aliexpress.com/product-fm/557819688-Tach-Hour-Meter-for-Motorcycle-ATV-Snowmobile-Boat-New-wholesalers.htmlThe problem is that the wire is not long enough, because i want to install it on the front. This is what is written on the wire that comes with it: "E249743 AWM 1015 22AWG 105°C 600V VW-1 CHENGXING" I got another wire (Not exactly the same), and it's working with it, but as long as the wire is short. when i try with a longer piece of wire, the tachometer is not working or it's showing incorrect data. I can't find the exact wire type, and also i'm not sure if there isn't a length limitation. Do you know what type of wire can work with that? Anyone have this type of tachometer and made it work with a longer wire? Thank you.
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Post by gingel on Jun 25, 2012 2:11:22 GMT -6
Thank you.
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