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Post by MrBraco on Feb 21, 2011 11:42:36 GMT -5
Hello all, I took the liberty take open my scoot's belly so i could get some advice on the maintenance. please look at the video (10min) and tell my your opinion on the general condition of my scooter, engine wise or more. i am open to all suggestions. Keep in mind is currently has 11500 (mls or km) on dash.
I apologize for the bad sound.
So simply tell me what you see. Thank you.
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Post by sprocket on Feb 21, 2011 11:51:04 GMT -5
Sorry... it is too hard to really see the condition of the engine from the video
But, if it has over 11,500 kms on it I would replace the engine...and the front and rear wheel bearings. Then you should be good to go...
It depends on what you want to spend...
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Post by braveheart on Feb 21, 2011 11:58:16 GMT -5
Long case 150cc new complete: $450.00 Short case new: $400.00 Compare these prices, do some research, decide if you want new..LOL....
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Post by sprocket on Feb 21, 2011 12:19:38 GMT -5
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Post by buiditright on Feb 21, 2011 12:37:46 GMT -5
why did you tear down your scooter in the first place???
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Post by lshigham on Feb 21, 2011 12:38:57 GMT -5
why did you tear down your scooter in the first place??? If it ain't broke don't fix it
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Post by buiditright on Feb 21, 2011 13:05:44 GMT -5
I rest my case that is why I asked that question. LOL
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Post by MrBraco on Feb 21, 2011 13:49:43 GMT -5
why did you tear down your scooter in the first place??? The problem I had appears to be compression, or some like that. See this post -> scootdawg.proboards.com/index.cgi?action=gotopost&board=talk&thread=36094&post=356934After i rebuilt from this tear down, i noticed a small size air leak by the air filter outlet tube, air box side. I fixed it with some plastic melting and roof patch ;D. after test drive, the scoot was literally flying up to 65! could gone higher if i had the time! Plus, did anybody really looked the video for my questions? instead of trying to sell me a new scooter??? What about the gasket? cover? exhaust?..?
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Post by buiditright on Feb 21, 2011 13:56:23 GMT -5
your gasket was fine and I did not try to sell you a new scoot just wanted to know why you tore it down. If you had a compression issue then ok. What cover? Bill
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Post by sprocket on Feb 21, 2011 14:34:08 GMT -5
You asked my opinion and I gave it. With that many miles on a scooter it is nearing the end of the road...
I looked at the video and after recovering from sea-sickness, I gave you my suggestions. I don't sell anything, just didn't want to see anyone throwing good money after bad...
Why did you pull it all apart...I thought you has other issues???
Ya, if the exhaust is leaking replace the gasket...
I don't care about the neon. By the way they aren't neon they are LEDs
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Post by MrBraco on Feb 21, 2011 15:40:13 GMT -5
Ah!! now we are talking! ;D i know everybody want to help, no arms done. And my reel concern is "whats gonna break next ? judging by the video. 11500 and running fine, even after 1 year long dumped outside! I cleaned and fixed every thing i could. when many are getting rid of theirs when they reach 4000 miles, i had good reasons to be concerned. for example, i dont want to buy a new scoot if i just need new piston. From this to this , I am pretty proud. - i know i need new exhaust, and never have (or never saw) any gasket on my exhaust port from cyl head... (concern right there) - fan cover covering engine: do i need to put it back or not? - thank you for the bearing advice. --- sea-sickness is good, let's you know you are alive! ---
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Post by ottersea on Feb 21, 2011 15:43:53 GMT -5
Question? Why is it that a engine with 11,500 klicks on it is considered dead? That is only like 7100 miles. Do these engines not last that long? Why? Any info on that?
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Post by buiditright on Feb 21, 2011 16:08:33 GMT -5
Well I have one with over 13,000 miles on it and it still runs fine with original crank and no noise. Yes you do need to put that cover back on. It is what helps to cool the motor. It NEEDS to be there. The gasket on the exhaust port is what has to come out to put a new one on but the one that is there is ok. If it is not leaking you do not have to replace it. There is a little ring that is in there. It has two (2) bands of metal with gasket material inbetween them.
You can do a top of your motor with piston, rings, wrist pin, circle clips, gaskets will give you your compression back and help you get more miles out of your 150. As long as you use a good oil ( I use synthetic) and change it regular to maintain good berings in the bottom of your motor.
Bill
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Post by sprocket on Feb 21, 2011 16:49:13 GMT -5
>>Do these engines not last that long? Why? Any info on that?
I know a couple of people that have over 15,000 miles on their scooters but they take care of them.
Fix things before they break, and not push the crap out of them...
Then change the oil and the gear oil regularly, and adjust the valves about every 2000 miles.
One of the most common problem is the piston comes up and wacks a valve...these are 'interference' engines.
There are probably about 60 different manufacturers of GY6 engines. Some are good, some are terrible...some have quality control and use decent parts other use whatever they can get...
Its a crap shoot quality wise..
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Post by buiditright on Feb 21, 2011 16:54:35 GMT -5
Also when you put it back together make sure you use good piston and rings. I use Japanes parts when I build mine. Bill
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Post by randy on Feb 27, 2011 8:18:11 GMT -5
Did you check the valve clearance/ If they are out of adjustment that will affect the compression.
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Post by MrBraco on Feb 28, 2011 11:13:16 GMT -5
Did you check the valve clearance/ If they are out of adjustment that will affect the compression. yes i did, but now, if i start and run the scoot, it works fine for 15-20 minutes up to 60-65mph, it bugs down once the engine is warmed up, can't pass 35-40.
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Post by quest4fire on Feb 28, 2011 11:49:46 GMT -5
7100 miles for a motor is pathetic. Tell me it isn't true. With proper care a scooter has got to go a lot further than that or they aren't worth the rock bottom prices they are going for. With the initial work you have to do, and the constant valve adjustments and other pesky tasks, you are paying too much.
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Post by MrBraco on Feb 28, 2011 12:43:12 GMT -5
being from europe, i know for fact that scooter can run A LOT more than that, that is for MBK, Yamaha, Honda, Derbi, Gilera and such.. But in the USA, "Chinese" scooters having a so called "cheap reputation", I am not sure if it worth try to fix and maintain or if it is better to barely use it like for short distance. Personally, it is my main transportation, since my car is locked down for misc reasons... I always like when somebody tells me they went around the world on a stock GY6!! that a like! That is why i did this thread: scootdawg.proboards.com/index.cgi?board=talk&action=display&thread=36342
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Post by fast150 on Feb 28, 2011 13:17:09 GMT -5
MrBraco.. I have this same scooter! mine is a JMStar Z-bike and the speedometer is different from yours... mine is in mph and doesnt have a tach...it has a digital clock instead.. Mine will also do over 60 mph about 62 or 63 depending on how windy it is.. im glad you said this because when I said it noone on here believed me and said I was basically lying... I have had this bike do 70 mph down a very long hill... .. interesting.. Mine also doesnt have a exhaust gasket.... its a lil loud but I still drive the ever living sh!t out of it about 50 to 60 miles a day.. I bought it less than 2 weeks ago and have already put 500 miles on it! I bought mine used...it was about 1200 miles now it has 1754... not kilometers.. miles... I have looked up this bike from different manufacturers all over the internet.. and everyone I seen, the owner claims it is unusually fast for a 150... and noone knows exactly why.. weird.
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Post by sprocket on Feb 28, 2011 14:56:08 GMT -5
>>100 miles for a motor is pathetic
It depends on who makes the engine plain and simple.
Some casting are great with good crystal structure and other casting are full of porosity and air pockets... A real problem is that some of the castings are very thin particularly where the cam chain runs. This area has always been trouble on a GY6 designs. Often engines are used to make moulds for new production and this cause very thing wall sections...
Generally, castings, rings, cranks and pistons etc from Taiwan are far superior to most Chinese versions.
The reason for the valve adjustments by the way is because of the soft aluminum heads. Change that out to a cast iron racing head and you would only need to to a a re-gap every 10,000 miles.
Honda engines in the 1970s had the same problem. Now Japanese manufactures have better alloys and it isn't such a problem...but most of this exotic stuff is too expensive...
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Post by sprocket on Feb 28, 2011 14:59:10 GMT -5
>>>fast150
You need to use a GSP. The speedos on these scooters can be way off. 8mph fast is about standard
You may want to reconsider an exhaust gasket.. you could burn out the exhaust valve...
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Post by fast150 on Feb 28, 2011 19:42:27 GMT -5
I have used a gps...my speedometer is actually pretty damn close to accurate... that 70 was down a very steep and long hill lol...usually it runs about 60... if it is really really windy about 55 but on a good day , not much wind and on a level surface it WILL top 60 mph... but not by much... also... can you explain to me how an exhaust leak can burn out a valve? im not being a smartass. im really trying to learn why, I've heard this alot.. almost every vehicle i've had in my entire life has had an exhaust leak and ive yet to burnout a valve... the studs where my exhaust mounts into the head are stripped and I dont even see how its possible to change them to be honest, there is no room to take them out, the top of the studs would hit the engine...?!?!?! pleaseeee helppp...
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Post by edfr on Feb 28, 2011 21:25:47 GMT -5
Fast150, can you take a picture of the Header Flange connected to the head. If the STUDS are still in the engine and the Header Flange is on held with the nuts but not tight because they studs are stripped. You can take the Header Pipe off the Studs and get VISE GRIPS and UNSCREW the Studs out of the Head. Are the Nuts that are holding the Header Pipe the Acron nuts or just regular nuts? If its the Acron nuts you probably can put a couple of washers and then use regular Nuts to screw the Header Pipe Flange down on the studs.
So take a picture of your situation and it will be easier to determine what you are talking about that you cannot get to them. I have changed many broken studs that is why I ask. Lefty
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Post by sprocket on Mar 1, 2011 13:24:20 GMT -5
>>I've heard this alot.. almost every vehicle i've had in my entire life has had an exhaust leak and ive yet to burnout a valve...
You have been lucky. It has to do with the operating temperature of the valve train and back pressure.
Check around the net there are many website that reference this in detail.
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