New Like 50 2t + Newbie Rider = good juju (life, breaking in a new engine, etc.)

[wassonii]

Strange days, indeed. With the primary hole for my airbox derestricted and an 88 main jet all was well. Added a secondary hole on the underside of the airbox (3/8 of an inch and on the correct side of the air filter). Tried some 7.7g weights to see what that would do, as opposed to the 8g I had been running. About a week ago, while doing some test runs, the scooter slowed down at about full throttle and the engine cut off. Not a seize as the rear wheel never locked. Started right up (within a minute) and I erturned home and blocked the new hole. I have played with blocking the second hole using aluminum tape (3/4, 1/2 way, etc) and all had been going well. (I should note that plug chops along the way indicate a slightly rich mix - coffee brown to slightly darker. No sticky residue. No particulates) After the initial engine reaction, I went to my mechanic and his initial thought was that maybe the petcock wasn't receiving the vacuum that it needed with the extra hole.
Yesterday, I tried leaving the secondary hole only slightly blocked. On the way to work, the engine did it again (I should note that for either time this has happened, there has been no definitive sound associated with the power decrease or shut off), but this time, the engine would not start back up. After the walk of shame, I covered the scoot and went to work to wait to take a look in daylight this A.M. Pulled the most recent plug and it looks about the same as the last described. Topped off the oil (it was low, but not low enough to set off the light. Still, I wanted to leave no stone unturned at this point.) It will not start with the starter. I am about to return to it to see what a kickstart will do, but wanted to post this interesting conundrum as I am presently stumped...and I needed a cigarette before returning to it. Never a dull moment:)

[wassonii]

Right, then. Kick start yields nada. Of note: the kill switch has definitely not been engaged in any of this process. I promise that was the first thing I checked.

[wassonii]

I don't have time today, but will change out the fuel filter to see if there is some blockage. Any other suggestions are greatly appreciated.

[Areomyst]

Anytime I have a no-start situation I check spark, fuel, and compression.  On a 2-stroke I also do a leak down pressure test.  Even if you suspect the culprit, it's best to do these things, and get the facts before trying to solve the equation.  You can't solve an equation without enough variables. 

I think you should put the airbox restrictor back in, and block the drilled hole too. With the silent pro, the main jet changed, and the sliders the bike should run pretty good.  The stock carb isn't really made to be adjusted much (no needle clip adjustment, and on the new Likes that I've worked on, they have a welch plug over the pilot adjustment) and there's not much gain to be had in this area other than a louder scooter and worse gas milage. 

That said, I have removed the restrictor, re-jetted the carb, and swapped exhaust (Leo Vince Touring, and Leo Vince SP3) along with clutch springs and dr. pulley sliders.  This helped the bike tremendously, but you could tell that there was a lean spot during the transition between 1/4 and 3/4 throttle, and without being able to really adjust the needle and pilot circuit accordingly I don't feel that it was worth doing.

The Silent Pro is a cool exhaust!  Congrats on that.

Keep us posted on your progress.    Those things are soooo slow in stock form. It sounds like you've done good work so far!  Keep it up.

~Josh

[zombie]

What J. said... My impression is a soft seize. You may have been cruising in that "lean spot" Compression test would be first on the list. 120psi or more is good. below 120 would explain it all. Your new pipe is far more efficient at scavenging the cyl..
The plug may not show lean because the soft seize is created by heat, and the tire will still spin. Try the compression, and maybe a new COLDER plug to bring down the heat

[wassonii]

Thank you both very much! While I have been assembling a tool kit along the way, a compression tester and volt meter were on the list and as yet have not been purchased. I have paid heed to the mantra 'spark, fuel, compression' but was going at the first variable I knew I could ascertain. Josh I appreciate sincerely your reiteration of it. Sometimes it is easy to focus on one thing and lose sight of the bigger picture, cause/effect within the whole.
As soon as this most recent situation occurred, I taped over the secondary hole and am making plans to create a more permanent seal for it. I fear that I am about to learn an expensive lesson, but I do love my little Like. Josh, they are indeed slow in initial unrestricted form (new boss and 82 jet).
Without having yet done a compression test, I can tell you that the kickstarter doesn't offer as much resistance as it once did. I was hoping (erroneously, likely) that I might have kicked too hard and sprung the spring, but I believe that it is telling me something else. Yesterday was a 2 show day at the theatre so I wasn't able to return to my scooter and since I have no workspace/area of my own, today is right out with the coming rain.
Being the packrat that I am, I have kept all parts played with up to this point, and will return the airbox restrictor to its' place. I will, though, likely leave the silencer (long corrugated rubber tube) off.
All this being said, if I can't get it running by Tuesday, I shall have to get it carted to my mechanic.
Zombie, do you have a suggestion for colder plug. At least at my regular purveyor, I don't see a number higher/colder than 8 for this plug type, though admittedly I haven't done research elsewhere yet, having focused last night on infos related to the points you two have made.
Thank you very much! I do love my 2 stroke and am trying to teach myself to be a better, more hands on owner.

[zombie]

http://www.mxlife.cz/zapalovaci-svicky/884-svicka-ngk-br9hsa.html


I order mine from Taiwan as they are not sold in the US. BR9HSA NGK.  Jiangwayne carries them, and I buy 6 at a time. Comes to about $25.00 shipped. http://www.jiangwayne.com/scooter/parts.php
Shops in the US cannot even order them

[wassonii]

Thank you. The only thing close I found is the BR9HS. I can't make out what difference the "S" vs "SA" is on the NGK Design Symbols as "S" indicates standard, "A" indicates special design but there is no "SA" given. Tomorrow I get a compression tester and start figuring things out as best able.

[zombie]

The 9hs is really a marine plug. It has a completely different insulator, and is flush with the inside of the head. The HSA's tip protrudes into the head starting the flame front at a different spot. The HS WILL work in a scoot but you lose power due to longer timing in flame travel. Milliseconds matter.

[wassonii]

Understood. Thank you. I wouldn't have ordered them without consulting first. And I do believe ms matters!

[zombie]

And I do believe ms matters!
If you happen to run into my wife (very good chance) tell her! She don't want to here it from me...

[wassonii]

Nice!

[wassonii]

Compression is 115 w/electric starter. 120 with kickstarter.

[wassonii]

Definitely getting spark at the plug.
I did go ahead and replace the restriction in the throat of the airbox after checking compression.

[Areomyst]

120 is pretty low according to the manual.  You should be around 160 or so...

 You can remove the exhaust, and look up into the exhaust port to see the piston and rings.  If there are scratches and scarring on the parts, you should be able to see them.

~Josh