loss of topend power??

[Goat Herder]

How well is your motor breathing. Do you have a home made filter on your carb? These ch realy need to breath . Mine using three layers of panty hose. There are better filters than this . I had frame clearance issues gave up used the panty hose, its worked for 4000 miles. Would suggest using a better filter though. Mine is still a running!

 

[Pablo]

Let me take a moment to go into better detail, At 25% to 50% throttle the engine has great power and torque. From 50% to I'm guessing 75% the "power band" seems to flatten out. Any more than 3/4 throttle the engine starts to stutter and sounds like an ignition miss, Schwinn wireless speedo says it happens at 26 mph. This engine and my riding habbits seem to like cruising at 20 to 25 mph. Let me also state that I'm pushing 300lbs!

Sounds like an exhaust issue. I suggest a tuned pipe.

 

[bigben77]

I am running the stock filter, I made the holes bigger by reaming them with a cone shaped stone bit.

 

[Ghost0]

Sounds like it is going fat on the top end, need to lean it out. Try a smaller jet but read your plug first.

 

[bigdreamz2000]

Maybe your clutch is giving out a little near the top? 300lbs might be enough to do that.

 

[bigben77]

I try to clean and adjust the clutch every weekend. That's my tune up time

 

[Dave31]

After five years and well over 4,000 miles...I have never had to adjust my clutch????

 

[bigdreamz2000]

BigBen, I too have over 500miles on my bike and never have adjusted the clutch. I still use what was set at the factory. What are you having to adjust? The directions that came with my bike say something about adjusting the screw on the big gear, and of course there is the brass fitting the holds that clutch cable in place.

 

[bigben77]

I just like to make sure that everything is nice and tight when I work on my bike. I have a mental checklist that I go through. I was refering to the flower nut on the clutch plate, I don't adjust it all the time, just give it a quick inspection. By adjustment I was talking about the cable adjustment hardware mostly. The cable likes to chew up those aluminum tid bits.

 

[Bikesthatgo]

Hi, Having the same problems with an engine as you describe, but have done just about every thing except change engines, its fine upto about 70% throttle then sort of changes firing pattern.
But take it out next day and for the first 4 mile its as good as gold, then start it again, problem is back.
I can see why some refer to them as China girl motors, I think the specs they're built on allow them to change moods.
We have 5 bikes in the household here, and have had clutch problems with 2, and that problem was the actuator moved almost around to the cable post, the only way to fix it was to put a small piece of 8mm rod in behind the cam pin, and not forgetting the plug cap had 2 of those fall apart totally, one we couldn't even repair to get home with.
Also there is lots of difference between engines, one bike you have to have both hand on the bars when you accelerate as it just kakes off.
But all in all what a hobby, and so affordable have just ordered 10 more engines 5 of the F50cc and 5 of the F80s, so we have lots of fun coming.
Cheers and have fun

 

[Saddletramp1200]

Welcome to The forum. Don't tell anyone but the bike kits differ due to price paid for them. The more expencive ones are better. I use THATSDAX. between you and I.