Cough and Die? By roakaun (Read 581 times)

[roakaun]

OK.. here's the deal:
The Subject: a 260 Linhai/Diamo Turista.  2K miles.Very good condition. Original parts. Runs very well at speed. Using it for morning work commute (3 miles) and occasional weekend ride (30/40ish miles).
The Problem: When coming to a stop, and off the throttle completely, scoot will sometimes cough and die. Sometimes before it even rolls to a stop. Sometimes after a brief idle sit. Cold or hot.
This is VERY annoying, and at times, VERY unsafe, such as when I'm perhaps trying to CROSS TRAFFIC in a left turn (has happened twice so far).
Before I strip off cowling and replace $$$ worth of ignition/carb/fuel lines, I was wondering if anyone else had a related problem on their own scoot, and what they did to fix this situation.
I have a new/better spark plug, and am pondering a hotter coil/wire, but if this is a simple adjustment or fix, I'd rather save budget money for the time being. You know how it is.
Simple adjust up of the idle speed? Check carb mixture pin? Sacrifice a 49cc bolt on bike motor to the ScooterGods (I've an extra I need to dispose of)?
I'm fairly handy with auto mech-a-necks, which one learns if one ever has a Ford, so a bit of wrenching will not be a problem; it's just that I'm still learning the quirks of these single cylinder little darlings, and don't want to make a total hash of it.
Any and all advice will be appreciated!

[fflintstone]

I haven't welcomed you yet,so welcome to the forum--that problem is chronic with our Chinese 250 scoots--and most of the members will tell you to check your valve adjustment--when we have about 2 to 5 thousand miles on them they get to where they will die at a stop sign,cold or hot..our valves need t be at .oo4 on the intake and .006 on the exhaust valve--it also helps with easier starting--seems like the valves tighten up after a few thousand miles for some reason--even if this is not the problem,it won't hurt to adjust them anyhow--I would start with that before throwing parts at it..it helped me..hang in there,some other members will probably chime in pretty soon--JR will tell you the same thing ,I am sure--good luck,fflintstone

[alleyoop]

FFlintstone is right on, those are classic symptoms of tight valves. What is happening is most likely the EXHAUST valve is not sealing an staying open a little when hot and the motor looses compression and it will not HOLD LOW IDLE. To keep it running when coming to stops you have to keep goosing the throttle so it will not die.
Alleyoop

[JR]

Classic and the first thing a linhai will do, they are not very forgiving with the valves off.

JR

[richardthescooter3]

Yep, adjust the valves and you will be ready to ride again

[roakaun]

OK... looked into the service manual (for a majesty, pretty darn close match, it seems) and everything seems on the up and up except for: remove the gas tank? and (fanfare) an Official Valve Adjustment Tool.
Right.
From what I can see, it seems to be a simple stamped 'wrench' with a square cut out. Very possible a Linhai don't need that, and a pair of pliers will do.
But I don't want to scar up something unnecessarily. If I'm going to mess something up, I want to DESTROY it. You know how it goes. (I'd prolly use vise grips and a ball peen)
How about y'all? What have you used to do this simple adjustment? One way or the other, I'll prolly tear into the job late Saturday or early Sunday, and as it's been said: Knowing Is Half The Battle.
Lacking that, I'm thinking Nukes.

[scot]

I would use the proper tool for adjusting valves,its tool similar to gaping your spark plug an helps to gage the proper gap,an using the right tools gets the job done with out wrecking anything yes I have done the same ,using the wrong tool then :-XBut yes I pare of pliers may come in handy allways hammer I don't know,there are some videos on youtube on valve adjusting ,

[roakaun]

(sigh)
I fought the Scoot.. and the Scoot Won.
This time. Took me over an hour and a half to get HALF way down into stuff needed to take off the body to GET to the engine topside. Side panels, back grab bar, back light housing, BACK side panels, seat, and, what defeated me for now, the mid body 'trunk component' that must come out front first, after disconnecting a couple of switches and the seat hydrolic lift. Urgh. After all that, my back said 'Nothin' doin', and I had to put it all back together. Didin't even get to try to remove the gas tank to gain access to the lifter ports to adjust anything.
I now know WHY that one motorcycle tech rolled his eyes after I said I had a scooter: "It takes (fracking) longer to take the (feltergarb) covers off then it does to FIX the P.O.S.!" (adjusted actual quote)
Well, on the plus side, the next time I try this, the outer covers will be quicker.
I'm going to attempt a slight idle speed adjust, and see if that will work for now.
Nukes are still an option.

[alleyoop]

Yea bringing up the idle should help some it all depends on how tight and open the valves are and if it is enough to keep it running.
Alleyoop

[ellpee]

I'm dreading the day when I inevitably have to get at the upper part of my 244 engine; I went as far once as removing the rear panels to work on R/R, and there was still lots of plastic and seat and other stuff between me and the engine. For right now, it's running fine at almost 5k miles, hope it stays that way for a long time.

[alleyoop]

Well the 244 Helix is much easier motor to work on, try a LINHAI you have to take just about everything off just to adjust the valves.
Alleyoop

[roakaun]

Update! I've found something to fix that only requires ONE PANEL to get to!
The Kick Stand Safety Switch!
My scoot left me stranded at my local Waffle House this morning, and would NOT start no way, no how. I thought I ran outta gas. Or perhaps my coil blew. Or the spark plug wire fell off. Or the fuel pump was faulty. Or I got some water in the gas. Or.. or.. or..
But no. one silly, single little micro switch decided to fail, and the fix involved me sacrificing a one inch bit of Motorola ear phone wire placed inside the safety switch harness plug to short across it.
And.... Varroom.
Memory for the win (later in the day, anyways): *former owner* "Yah, and occasionally, you have to jiggle the kickstand to get it to fire up, donno why"

[alleyoop]

I think if you just join the wires instead of jumping them would make better contact. I bet that little piece of wire is not making good contact is why you have to jiggle it sometimes.
Alleyoop

Or make a jumper like this:
KILL SWITCH JUMPER:

[bones113]

I have been there with the kickstand switch. I have went thru 2 of them on my Linhai 300. I finally took it off and spliced the wires together. If you take yours off make sure your kickstand is up before taking off. I am not saying that you should take yours off as it is a way to kill your motor should the need arises but until I order another one this will have to do. There must be a manufacturing problem with these switches. If my 3rd one goes out I will take it off permanently. To me it is not worth repeatedly spending money on a defective item.