QingQi (Qlink) 200GY Illustrated Valve Adjustment

[Zorge]

Something like disclaimer: previously written is related to climate, fuel, oil and Qingqi/Pioneer motorcycles ridden in my part of the world.

[d.j.jake1/2]

im so sorry, i dont mean anything, i was only used to it in our country forum that every ones calling each other sir as a sign of respect. and thank you so much brother zorge, ill do that combination to my next valve clearance. probably next change oil. yahowww... cant wait to see the difference.

[Zorge]

Don't be sorry - there is no reason for that. Different countries, different customs.

[Real4real]

Nice thread. But loose valves means less lift and that means less power. Most China bikes have valve clearances listed with engine specs. Just surf the engine make for these important clearances.

[ChinaV]

Most China bikes have valve clearances listed with engine specs. Just surf the engine make for these important clearances.

Unfortunately this is not true. Very few companies post accurate specs on their engines, and almost everyone relies on using the specs from whatever Japanese engine they copied.

Cheers!
ChinaV

[Real4real]

Below are the specs for the engine in my Saga 250cc enduro found on the manufacturer or distributers web site.

ModelZS167FMM (CG250)
ManufacturerChongqing Zongshen
TypeSingle-cylinder, vertical, four-stroke, air-cooled
Maximum power and corresponding speed kW / (r / min)11.5 / 6500
Rated power and corresponding speed kW / (r / min)11.0 / 6500
Maximum torque and corresponding speed N • m / (r / min)17.5 / 5500
Minimum Idling speed r / min1400 ± 100
Cylinder diameter mm67
Piston stroke mm65
Total displacement ml229.2
Compression ratio9.2:1
Ignition timingBefore TDC 15 ° (1400r/min)
InletThe following set camshaft
IgnitionC.D.I electronic ignition
LubricationPressure, splash compound
Valve Timing*valve clearance* mm0.05-0.07
Clutch typeManual wet multi-plate
Constant mesh five-speed two-stage variable speed driveReduction ratio"Primary: 3.333; a file: 2.909,Second gear: 1.867; third gear: 1.389,Fourth gear: 1.150; five files: 0.9545 "
Starting method* Electric start and kick-start
Spark Plug TypeJapanese Model D8EA (NGK) or D8TC (LG)
Gasoline brands≥ RQ90
Oil gradeSF15W / 40
ML total capacity of oil1100
Dimensions mm358 × 324 × 458

Be cautious using specs to maintain your newer bike from a design made 40 years ago. Most engines being made in China have better materials and slightly updated designs. Exaust valves are made of harder and/or slightly different materials reducing thermal growth eliminating the need for excessive clearance between rocker and valve. This is done to provide easier starts, quiet operation and the high rpm's achieved in most engines made in China today. Use the original 40 year old design specs as a guide and only as a last resort. The dealers that provide service for these bikes have sevice manuals specific to these newer engines and can provide this infomation as well. It is worth while investing the time to find any specifications direct from the manufacturer for proper operation and life span of your engine.
I agree with ChinaV that most people do use specs from the original 40 year old design when turning wreches on thier bikes, but they do this in error and most cause damage to thier newer engines when using these outdated specs and write it off as poor quality engine from China.

[Real4real]

I emailed the manufacturer of ChinaV's 250cc bike or the model that was easily found on the internet, a QM250-2D. ChinaV provided me with a request for info for this bike via private msgs. In less than 24hrs I recived this reponce.

Dear Sir:The clearance is 0.05-0.07mm
Best rgds Director of Sales Department ofJinan Qingqi Foreign Trading Co.,Ltd
Office address:No.369 Chonghua Road, Jinan high&new technology industry zone,China

It is clearly true that 10mins of time on the internet and email can get you the proper specs for your new China bike direct from the manufacturer rather than using outdated specs from the 1970's used on an engine built by someone else. Unlike ChinaV might have done, spend the time to get the specs from the manufacturer, it's well worth the time to have your bike running at it's best.
FYI, The address I have included in this post is public infomation and can easily be found on thier website.

[MJH]

Intake 0.03-0.08mm
Exhaust 0.08-0.13
I believe that is what is the specs on the actual Suzuki version of the engine.


I would not use the numbers you got,. There could be a range for both and they could be different.
How are you interpreting those, why so tight on the exhaust side? Did they offer any explanation as to why it would be different then the original design? Did they offer any reason for the exhaust to be the same as the intake when on the original design they are not?


You cannot get specs from the 1970’s on that engine it is a newer engine, I do not think it has been in production for more then ten years.


I would check mine and see if they fall into the range that Suzuki offers, if so then it would be unwise to tighten the exhaust side as tight as the Jinan suggested range.


I would not trust them, the shop manual I have has allot of obvious errors in it.

[Real4real]

I only expressed caution when using specs from another engine manufacturer for our China bikes.
The reason for exaust valves having the same specs is explained above in one of my earlier posts in this thread. Yes I am aware that the exaust valve gets hotter than the intake valve but most engine manufacturers have solved this problem. Different alloys expand at different rates when heated and when you make the exaust valve and intake valve out of different alloys the same expansion from exaust and intake can be achieved, simmilar to titanium valves and connecting rods used in high performance engines to reduce weight and to maintain tight clearances under all engine conditions.
A Chevy V8, Ford V8 and a Dodge V8 all seem very simmilar and all have been swaping design features for years but it would be unwise to use specifications from Chevy to set up a Ford or Dodge engine, right?
I currently have 3 four stroke engines made in China, I have used the manufacturers specs to set the valves on all of them without any problems. I have even had to remove the head from one after years of abuse and found no burnt valves or carbon build up between the valve and seat.
You and others not willing to use the engine manufacturers specs can set your valves however you want but I will continue to set mine according to the manufacturer to ensure my bike run for years.
It was pointed out earlier in this thread that you might get more power from loose rocker to valve clearances but a dragster has more power than most production vehicles but most drag engines only get a few pulls and then need to be rebuilt. This is not something I want for my street legal bike.
I know that China has lacked from making quality products in the past and I do slightly understand people not trusting or understanding the specifications they request you use. It's now 2013 time to move on and except that China does and will continue to produce a good engine and has the skills in place to make a good product. The only problem engines made in China now face is people that feel they are smarter than the engine manufacturers and poorly maintaining thier engines. I have known many so called mechanics with licences do simmilar things you have done and it usualy resulted in a wrecked engine or at least bent valves from what we are talking about and striped bolts from torque specs found from another manufacturer.
You should read your manual with caution as well, most are created in the language of the manufacturer and translated to multiple languages by people that might not have enough mechanical experience to express what is trying to be said, this includes converting measurments. I have delt with this on many CNC machines I have programed, run, maintained and repaired from around the world and any time I had an issue with the manual seeming incorrect it was easily clarified when I contacted the manufacturer.

[MJH]

I agree that you should follow the manufactures specifications, if they are in a professional format that has been verified, that is not the same as getting an email from sales, the only thing sales people are experts at is Bull Shit, for real are you in sales.