Recent Posts  By   (Read times)

I need to adjust a carb on a Hyosung Sense SD50 2 stroke. I am concerned about making it overheat if I make it too lean. Any guidance here?

It's a stock system. I'll have to check the plug later as my standard sized plug wrench isn't big enough to fit on it. I gave it a quickie valve adjustment while it was running. I'll do it "the right way" later.
Please see my new post here for some more details and thank you for your help.

thescooterprofessor.proboards.com/thread/4118/engine-runs-new-belt-variator

I just put a new belt and variator on this 250 Qlink Communter Helix clone. This is the same bike I made the vacuum and fuel pressure test video on. It was running horribly at open throttle and wouldn't go over about 45mph. Now with the new variator it isn't cutting out like it was, although it still feels like it's on the verge. Now it does about 50mph or more, I didn't push it on these small streets, but it might do more. It did 46-48 up a fairly steep bridge. Do you think the new variator is loading down the engine more than the old one? Unless I accidentally made something right while pushing around on the air box, fixing a vacuum leak, I think it's just that the bike can't rev too high with this new variator on it, thus avoiding the rpm at which it would usually cut out. Before I put the new variator on, the engine did better when getting up to speed than it did once it was going faster. That is, it would cut out once it got going. Is this change in engine performance a clue to what is going on with this engine?

I took some vacuum and fuel pressure readings, from a 2008 Qlink Commuter 250 Helix clone, and the results are interesting because this bike runs like crap at WOT. I will post videos and/or pictures when I can, but for now here is a list of vacuum and fuel pressure readings.



These readings are on the stand.

Fuel Pressure:

1.2 PSIG @ 2000 RPM

1.6 PSIG @ 3000 RPM

1.7 PSIG @ 4000 RPM

1.7 PSIG @ 5000 RPM

1.6 PSIG @ 6000 RPM

1.4 PSIG @ 7000 RPM

1.5 PSIG @ 8000 RPM

When I open the throttle any more, the readings drop drastically until I let of the gas some and let it back down in RPMS, then it recovers and goes back up.



Vacuum:

1 -5 INCHES Hg @ 1800 RPM Idling. Steady oscillation.

3 INCHES Hg @ 3000 RPM

3 INCHES Hg @ 4000 RPM

3 INCHES Hg @ 5000 RPM

3 INCHES Hg @ 6000 RPM

2.9 INCHES Hg @ 7000 RPM

2.9 INCHES Hg @ 8000 RPM

1-5 oscillating to 10 INCHES Hg and back, Goosing from idle to full throttle



After hitting 8000 RPM on the stand, when I open the throttle any more the readings go to about 1 INCH Hg and the "jerking" begins with RPMS jumping up and down, as though the gas is coming on and off rapidly.



I will note that I have not yet done a valve adjustment on this bike. I will also note that I seem to be getting poor gas mileage, about 45-50 mpg. I do not know what is standard for this fat and heavy 250 scooter.

A cursory propane vacuum leak test revealed no leaks, however I was not thorough in testing.


Anyone want to take a stab at what these readings mean?  I don't have any baseline data for this engine yet to compare to.

I'm guessing a vacuum leak somewhere.
Read more: itistheride.boards.net/thread/6945/using-gauges-guessing?page=3#ixzz3OptqwrZU

Here's a video of the tests:

I'd probably put the links on a separate bar.  From someone who used to build web pages.  I'd probably put the cute model on a front page, with your shop name and info, and links to all other stuff.  Thinking of it like a book.  She's on the cover, and the side bar is the table of contents for the website.  If you change the model once in a while it will give the guys something to look forward to.  In your link bar you might have sales and other promotions.  I'd work on search engine optimization, especially to get local traffic for the shop, if repairs are your main money.  You are obviously doing the right thing by being connected to these forums.  That gets your name and site link out on the web.  The more pages it's on, the more often you'll come up in searches from people like myself, searching for info on scooters.  I found out about scrappydog that way.  When I got my first scoot, I searched the model and found it in a forum.  It's a matter of taste and what works for you.  This pro-boards site is a nice model for a website.  It has a nice banner on top, links, then a body.  The style and colors look "modern".  I say "modern" because it will look old and outdated in a few years unless it is changed once in a while to keep up with the latest web fashions, but the color scheme is good.  A flat background with no dividers and other visual jewelry looks home made.  That's not always a bad thing though.