what would it take to get a good head on a gy6? By jct842 (Read 636 times)

[jct842]

I just did valves again today. symptoms....was running good one day refused to start the next.
3 times in less than 1400 miles! when you get comparing jap bikes you find some worn out at 50 or 60,000 miles that have never had a valve adjust. then they do make more power on the same size or smaller motors too. I did check compression before I took the valve cover off to be sure and it was under 100 lbs. after the valve adjust 150. I set both at 004. as long as you have clearance it will run and soon enough will require another adjustment no matter where you set them. they do seem to run better with less clearance though.

I am sure the biggest difference between china and jap out side of price is the head. they are better shaped inside and offer more efficiency and power. and materials got to be a bunch better as the jap. head doesn't let the valves pound up into the head requiring constant adjustment. I just wonder what would it take to get a good head on a gy6? with out a heavy duty investment?
it could not cost 30 0r $40 more to make one right. I believe the weakest part of a gy6 is the head. john

[Bashan]

I know a lot of people post with running issues and it turns out to be valve clearance. I just haven't had that happen on my bikes although I expected it to happen regularly. My wife's Bashan has 4K+ miles on it and I adjusted the valves once before we rode the Dragon's Tail. It wasn't running poorly I just thought I should check them. My Bashan hasn't required more than a couple adjustments and I did the Znen once because I just wanted to pull it apart. I think it comes down to the poor Chinese quality control, sometimes you get lucky, sometimes you don't. I do think they're getting better in that regard though. But yeah, it comes down to spending a little more money for big returns on reliability. Rich

[89newbie]

I think the valve situation could be much better if there were seats in the heads not bare Aluminum. Also of the stem heas were heat treated prior to assembly. A quality head is just that and would eliminate all the valve adjustments. Im not sure something like that is available at this point.

[kz1000st]

I don't think it's the head. These valve heads are spun welded to the stems and it probably killed the hardness of the material. I adjust my valves once a year. Most times they've only closed up a couple of thousandths. Keep in mind that these motors are spinning over 6,000 rpm where we run them. That's over 100 times per second. Run a Harley like that and let me know how long it lives. I'll bet a switch to better valves would stretch out adjustments by a factor of considerable.

[cookees]

good head??? make sure the beer is real cold...and tilt the glass!

[Bashan]

Nov 26, 2011 15:44:02 GMT -6 Random Hero said:

WOW i quickly read the title and missed a word I guess it has to be a clean comment about the valves...

You are naughty and must be punished!

Nov 26, 2011 19:13:01 GMT -6 cookees said:

good head??? make sure the beer is real cold...and tilt the glass!

And you are....well, you are Cookees....

Now I have a real question.......why can't they put hydraulic lifters on these engines so they would never need adjusting? Rich

[jct842]

I think hydraulic lifters may violate the KISS principle. if they just did it right like the old jap engines the guy at the lawnmower store could keep them running forever. and maybe a body that lifted off in one piece like some of the 50s scooters. john

[kz1000st]

and maybe a body that lifted off in one piece like some of the 50s scooters

Really. Have you seen the setup on a Hyosung? It lifts up like the hood on a car and lets you get at the motor. Even Rich's Fashion. Take off the seat and there's the motor, then move the adjuster until the clicking subsides. Ripping off most of the plastic to get at the valves is such a drag.

[89newbie]

Nov 27, 2011 9:58:07 GMT -6 kz1000st said:

and maybe a body that lifted off in one piece like some of the 50s scooters

Really. Have you seen the setup on a Hyosung? It lifts up like the hood on a car and lets you get at the motor. Even Rich's Fashion. Take off the seat and there's the motor, then move the adjuster until the clicking subsides. Ripping off most of the plastic to get at the valves is such a drag.
AS Dave says YEEEEEEEEPPPPPPP!! Love my JCL 150 but valve adjust??? Cross member in the way? It is now with the emissions head. REmove the plastics to get there sure thing after removing the screws , the passenger foot pegs the seat the down plastic below the seat and the battery to not short out on the positive terminal. Sad thing is I really love the wheelbase, brakes, 14 inch wheels, and performance.

[89newbie]

Nov 26, 2011 19:13:01 GMT -6 cookees said:

good head??? make sure the beer is real cold...and tilt the glass!

YA gotta do that with a real Burg Boilermaker!!