Xingyue ITA150 rebuild

taz001 · 06-24-2013, 09:35 AM

I recently rebuilt my scooter with new: crank, rod, pistion, rings, wrist pin, and cylinder. It turns over, seems to have compression, I took the spark plug out and grounded it against the valve cover and it has spark. Took the carb off and squirted starting fluid down the intake. Just won't start. Not even a pop. Exhaust dosen't seem to puff out the exhaust stroke as hard as I think it should. Maybe even has a little "suck" to it. The old piston came off the rod and I'm assuming slammed against the head, as evidenced by the bent rod. I didn't take the old valves out of the head and check to see if they were straight. I'm gonna do a compression check, as soon as my 10mm adapter gets here. What kind of number should I get? 20, 30, 40, 50, etc. psi? The rings haven't seated yet, as I have yet to have it running. Bad compression, I'm thinking bent valve(s), good compression I'm thinking timing. What say you?

**inuyasha** · 06-24-2013, 09:58 AM

Hi
100-125 psi is good, 125-150 psi is very good, and 150+ psi is great. If you don't have this level of compression then you have bad valves and/or bad piston rings. If you want, you can add a teaspoon or so of oil to the engine through the spark plug hole. Then try the compression test again. If compression is higher, then it's likely you have bad rings. The oil will seal the rings and give you better compression. If compression is the same, then you have bad/improper adjusted valves.
Try that and then we can go from there
Take care and ride safely my friend
Yours Hank

DW · 06-27-2013, 09:52 PM

If you get a vacuum at the exhaust your valves are to tight or your timing is off.

taz001 · 07-08-2013, 07:03 PM

Well guys I got my new tool, a 10mm to 14mm compression checker adapter. Did a compression test on my freshly reguilt engine. Guess what? NO compression---zero, zilch. So I removed the engine AGAIN. Pulled the head and took a look at the valves. Looky, Looky what no cookie. guess what I saw.
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Tada:

Here's a shot up the ol' exhaust port. Guess I shouldn't be able to see daylight between the valve and seat! Valve end is definately bent. Gonna buy a new set of valves, reassemble and try it again.

blueboy5000 · 07-12-2013, 09:45 AM

You also need a head! Get a new complete head, as lapping these valve seats is nearly impossible.

taz001 · 07-15-2013, 07:55 PM

When I line up on the green mark which is the end of the box enclosing the arrow beside the "T", the cam will not get horizontal in relationship to the top of the head. but when I line up either the individual red mark beside the "F" or the end of the arrow(depending on which tooth I use on the cam), the cam will get horizontal in relationship to the top of the head. Which mark then would be TDC? I'm thinking the end of the arrow, correct me if I'm wrong. Where I have the blue mark is the TDC indicator, also correct?

Cam is horizontal like this in reference to the top of the head, correct?

Thanks for the help guys.

blueboy5000 · 07-16-2013, 07:28 AM

The bottom pick is where your cam should be at TDC.

taz001 · 08-04-2013, 07:26 AM

Well set the timing just as it was in the picture. Installed and lapped the valves in the old head, took about 25-30 minutes because I hadn't already removed the intake valve. Put it all back together. Tried to start it and the battery wasn't up to it, so jumped it off and with the extra juice popped right off. Runs like a timex. Real jewel this one.

Questions again though. In general where do the fly weights on these 150cc GY6es engage? On my chinameter it also includes a tach. The fly weights seem to engage on this scoot at about 3-4 grand according to the onboard tach. I got it going real easy like then gave it 2/3 throttle and it ran up about 6 grand as the speed on ran up to 40-45 chinameters. The revs weren't changing but the speed kept increasing. Due to the varator closing up? When I first started it there was a little bogging and hesitation, but after it warmed up, the throttle response was very crisp with the pipe and K&N air filter. Yes, I did rejet. Also in general with these 150cc GY6es what is a safe redline? I'm gonna run it easy for the break in. On a rebuilt engine how many chinameters should break in be? I can tell this one's gonna be alot of fun. Thanks any response guys.

blueboy5000 · 08-05-2013, 03:19 PM

Safe redline is about 8000. The clutch (flyweights) engage at different rpms depending on the springs in the clutch.

06-24-2013, 09:58 AM	#2
inuyasha Join Date: Sep 2012 Location: West Haven CT Posts: 1,165	Hi 100-125 psi is good, 125-150 psi is very good, and 150+ psi is great. If you don't have this level of compression then you have bad valves and/or bad piston rings. If you want, you can add a teaspoon or so of oil to the engine through the spark plug hole. Then try the compression test again. If compression is higher, then it's likely you have bad rings. The oil will seal the rings and give you better compression. If compression is the same, then you have bad/improper adjusted valves. Try that and then we can go from there Take care and ride safely my friend Yours Hank __________________ "4wheels move the body 2 wheels move the soul" Duty, Honor, Country. Those three hallowed words reverently dictate what you ought to be, what you can be, what you will be. Douglas MacArthur
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07-08-2013, 07:03 PM	#4
taz001 Join Date: Jul 2012 Location: NE oHIo Posts: 160	Xingyue ITA150 rebuild Well guys I got my new tool, a 10mm to 14mm compression checker adapter. Did a compression test on my freshly reguilt engine. Guess what? NO compression---zero, zilch. So I removed the engine AGAIN. Pulled the head and took a look at the valves. Looky, Looky what no cookie. guess what I saw. . . . . . . . . . . . . wait for it, . . . . . . . . . . . . Tada: Here's a shot up the ol' exhaust port. Guess I shouldn't be able to see daylight between the valve and seat! Valve end is definately bent. Gonna buy a new set of valves, reassemble and try it again. __________________ 1981 C70 honda 2007 Xingyue ita 150t(X2) 1976 Vespa Bravo(2) 1980 Vespa Ciao 1967 Sears Allstate Do I continue? "Freedom is just another word for nothin' left to lose." Janis Joplin 1943-1970
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07-15-2013, 07:55 PM	#6
taz001 Join Date: Jul 2012 Location: NE oHIo Posts: 160	Rebuild--setting timing When I line up on the green mark which is the end of the box enclosing the arrow beside the "T", the cam will not get horizontal in relationship to the top of the head. but when I line up either the individual red mark beside the "F" or the end of the arrow(depending on which tooth I use on the cam), the cam will get horizontal in relationship to the top of the head. Which mark then would be TDC? I'm thinking the end of the arrow, correct me if I'm wrong. Where I have the blue mark is the TDC indicator, also correct? Cam is horizontal like this in reference to the top of the head, correct? Thanks for the help guys. __________________ 1981 C70 honda 2007 Xingyue ita 150t(X2) 1976 Vespa Bravo(2) 1980 Vespa Ciao 1967 Sears Allstate Do I continue? "Freedom is just another word for nothin' left to lose." Janis Joplin 1943-1970
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07-16-2013, 07:28 AM	#7
blueboy5000 Join Date: Jul 2011 Location: Connecticut Posts: 493	The bottom pick is where your cam should be at TDC. __________________ 2011 Roketa MC-23-150 4T 150cc 157 qmj 24mm carb w 115 main jet and paper cone air filter Manual petcock w Tygon fuel lines Scrappy Dog Scooters Retro-slash stainless straight-thru exhaust RED spring clutch Adjustable CDI (brand unknown, it's blue and red and works great!) KOSO high performance variator w 12g sliders Gates Powerlink 835-20-30 belt GPS verified 65mph on flats.
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08-04-2013, 07:26 AM	#8
taz001 Join Date: Jul 2012 Location: NE oHIo Posts: 160	Waaaahhoooo! Well set the timing just as it was in the picture. Installed and lapped the valves in the old head, took about 25-30 minutes because I hadn't already removed the intake valve. Put it all back together. Tried to start it and the battery wasn't up to it, so jumped it off and with the extra juice popped right off. Runs like a timex. Real jewel this one. Questions again though. In general where do the fly weights on these 150cc GY6es engage? On my chinameter it also includes a tach. The fly weights seem to engage on this scoot at about 3-4 grand according to the onboard tach. I got it going real easy like then gave it 2/3 throttle and it ran up about 6 grand as the speed on ran up to 40-45 chinameters. The revs weren't changing but the speed kept increasing. Due to the varator closing up? When I first started it there was a little bogging and hesitation, but after it warmed up, the throttle response was very crisp with the pipe and K&N air filter. Yes, I did rejet. Also in general with these 150cc GY6es what is a safe redline? I'm gonna run it easy for the break in. On a rebuilt engine how many chinameters should break in be? I can tell this one's gonna be alot of fun. Thanks any response guys. __________________ 1981 C70 honda 2007 Xingyue ita 150t(X2) 1976 Vespa Bravo(2) 1980 Vespa Ciao 1967 Sears Allstate Do I continue? "Freedom is just another word for nothin' left to lose." Janis Joplin 1943-1970
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08-05-2013, 03:19 PM	#9
blueboy5000 Join Date: Jul 2011 Location: Connecticut Posts: 493	Safe redline is about 8000. The clutch (flyweights) engage at different rpms depending on the springs in the clutch. __________________ 2011 Roketa MC-23-150 4T 150cc 157 qmj 24mm carb w 115 main jet and paper cone air filter Manual petcock w Tygon fuel lines Scrappy Dog Scooters Retro-slash stainless straight-thru exhaust RED spring clutch Adjustable CDI (brand unknown, it's blue and red and works great!) KOSO high performance variator w 12g sliders Gates Powerlink 835-20-30 belt GPS verified 65mph on flats.
	0