I may have done something rash! JMStar 250

[acvw74]

Today I decided that the 250 needed its windshield back (I think all the bugs flying about impacted my decision)...however I didn't care for the really tall screen. So I held my breath and cut the one that came with the bike.




I cut is using one of the vibrating saws - then eased the corners

[Deleted]

I'd love to find another cheap 250 to perform diabolical mutations to while I keep my Kymco intact, nice ride for little coin

[acvw74]

Jul 9, 2017 21:34:19 GMT -5 peascreek said:

I'd love to find another cheap 250 to perform diabolical mutations to while I keep my Kymco intact, nice ride for little coin

I wish I had more cash...wouldn't you know it found a 06 Kymco Grand Vista with about 10k on it for $500.

[acvw74]

I am going to challenge the waterless coolant claims about "never" overheating - I have a half gallon of flush and coolant on the way.

I will take notes and pictures for those interested.

[acvw74]

I have a half gallon of flush and half gallon of waterless coolant waiting in the wings...

I have to get the bike running right first...It will get to 40 or 45 and starts surging and will not go faster.
If I am hard on the throttle it does the same thing sooner. Feels like it isn't getting fuel at anything past 1/3 to 1/2 throttle.

I'm a little stuck - took the carb off and cleaned it (looked ok for 10yrs old)and replaced all the fuel lines...went from 6 small pieces spliced together to 3 pieces of new 3/16.

Been clipping the ends of vacuum lines to tighten them up.

Other ideas?

[acvw74]

Well...still working on the 250.

I have replaced all the vacuum hoses - Was going to replace the intake manifold, however - it didn't fit. So I cleaned the old one up (removed half a tube of RTV...no-Oring) installed a new O-Ring.

Bought some new jets for the carb - Found the carb had a 135 mainjet, that sounded big according to others? Dropped it to a 120.

Disassembled the vairiator - These are a bit different than the GY6 style...these have grease on the driveboss.

So, sorry for the delay...but it still won't go over 50ish... continues to surge feels like someone is putting the back brake and it wants to throw me over the bars...

[190mech]

Have you done a fuel flow test yet?Perhaps there is a restriction somewhere..

[acvw74]

I have - I even tried it at different levels in the tank...since the tank is above the carb.

A new CDI "racing" (yeah I know) came in the mail today - going to give it a run. Still thinking of going down to a 115 or 110 main jet.

[acvw74]

Ok...much the result I expected - except it try to flood when rolling off throttle.

Not really a surprise, I pulled the plug before my ride and it was almost completely covered in soot.

[190mech]

More questions,,Stock airbox?Air filter element good low time part??

[acvw74]

Sorry should have disclosed that earlier.
Yes, stock air box (this is an odd one too...it has a air filter for the CVT) and the air filter looks new.

Tonight - took 30 minutes and re-jetted the carb...went from a 120 main to a 110. Out on the road near my house...ran so nice and smooth upto about 60..maybe 65...felt a tiny bit of pulling/vibration but sooo much better!

Oddly...with the 120 mainjet temp never really got above half on the gauge...but now creeps back up like it did when I first got the bike.

[2stroked]

I would venture to guess that the extra fuel was washing the plug and cooling things a tiny amount. Idk about the CF Moto versions but my Honda CN runs just at or right above the half mark.
These bugger scootes will kinda make an impression in a person who's used to sub 100cc size scooters. I love the soft flowing ride...like loving a big o corn fed gal. Plenty of cushion for the bumps!! Lol just kidding. Had to say that just heard Rodney Carribgton Fat Girls so..

[acvw74]

A scary bald tire kept me from riding at all....Oh and some very noisy swing arm bearings.

A new Pirelli from the local Honda shop...and the bike is back on the road.
The 110 mainjet seems to be about right - still feeling an occasional stumble about 1/3 throttle...slowjet may be a bit big (38)...The bike runs cool at temps below 50 but will climb to the redline if I hold WOT too long.

The cooling system appears to be in good repair and the fan works - Something that has bothered me about this scoot is that the fan sits in the middle of the "tunnel" and there isn't anything to direct of force the air through the rad...

Somewhere...I have heard, read, or seen that air needs to be forced through the rad. At higher speeds the air will take the path of least resistance and go around the rad loosing cooling efficiency.

So...Had the "brilliant" idea to make my own shroud (for lack of a better word. I used blue painters tape to fill in the frame an make a channel directing it into the rad - its not perfect (yet) but I ran 15 miles at 50-55 and the gauge only got to half...then ran 26 miles at 55-65 (WOT) and the gauge crept to about 3/4 maintain below red....I think a little more work sealing up the airflow and I will have it..

Trouble is - painters tape isn't going to be a permanent solution - I need some ideas for a permanent fix.

This is the "before" pic - lots of room around the rad.

"Taped up"

[pinkscoot]

Jul 9, 2017 19:44:03 GMT -5 acvw74 said:

Today I decided that the 250 needed its windshield back (I think all the bugs flying about impacted my decision)...however I didn't care for the really tall screen. So I held my breath and cut the one that came with the bike.




I cut is using one of the vibrating saws - then eased the corners

Is this scoot a Reflex clone? If so I have a brand new windshield I would be more than happy to send you. As well as a front wheel with an okay tire.

[acvw74]

Its is suppose to be the reflex clone, but it takes the Helix windshield.

I appreciate the offer...I have been looking at a new windshield - I bobbed my a bit too much for high speeds.