HAAAAAALP!!!!!!!!!!! By Ernie (Read 589 times)

[Ernie]

I took the plastic off the back and I have the carb on my MP250A upside down. On the front end of the bottom closest to the engine manifold, there is a long brass screw which was turned out 4.5 turns. Behind this toward the center direction is a small 3mm circle which could be a plug. What are both of these things and what should I do with them?

Also, I have a slight fuel leak which appears to be between where the bottom fuel line connects to the carb. I snipped a piece off the line and plugged it back in. Is this enough with the little rabbit ear clamps the use or should I get a screw type hose clamp?

Thanks

Ernie

[JR]

OK Ernie if I'm following you right the first item is the A/F mixture screw and the second one is either a drain plug or the carb bowl drain screw?

Pictures would be most helpful. The hose will be fine with just the spring loaded typr clamp but I recommend you put new hose on and you can also use a screw type hose clamp or a smal electrical zip tie too.

Now if the first item you mentioned is indeed the A/F screw it's off badly! 4.5 turns is extemely rich!

Bottom it out and turn ir at 2.5 turns, again to be sure of the things you mentioned a picture can verify your description.

JR

[Ernie]

I set the mixture to 2.5 turns out. I let it warm up and it was stumbling all over the place and wanted to stall. I increased the idle to 2k. After warmed up, I gave a quick full twist on the throttle and it was straining to pick up rpms. Only thing I can figger is when I adjusted the valves(could only do the intake one-fuel tank in the way.) I must have made an error/ I had trouble getting the arrow exactly on the mark in the peep hole by the oil filler. I was off maybe 1mm.

I'm going to let it sit all night and tomorrow evening I will remove the valve cover and crank it around until I get maximum opening at the valve tappet and reset it to .004. Since I'm not doing the exhaust valve, it shouldn't matter having to align both marks for TDC.

Correct me if I'm wrong. Any other suggestions would be appreciated.

Ernie

[JR]

Ernie sometimes the allignment marks on doing the valve adjustment can be very frustarting to say the least but not doing the exhaust valve is a no-no, in fact more than 90% of the time the symptoms you are describing is a too tight exhaust valve.

We have a good tutorial in the tech section on doing the valves and yes there is one bolt on the exhaust valve cover that is a PITA to get to, I drop the belly pan and lay down and use a wrench on this one bolt and I also adjust the bottom valve from laying on the ground next to the scooter, bad knees will always find a better way! LOL

JR

[Ernie]

I tried laying on the floor and using a wrench. I couldn't get a grip on that little devil for love nor money.

I guess I will drop the bottom and try again. Maybe a 1/4" drive socket with a short extension will work.

Do those TDC marks have to be perfectly aligned?

Thanks for your help JR.

Ernie

[JR]

As close as possible and you said one was within 1mm that's close enough.

Also take the sparkplug out, it makes it a whole lot easier. A ratchet does help on the hard to get to one and you need to use a very good quality wrench or socket so it will not slip, the exhaust valve is critical, once it's properly adjusted you'll be amazed at how much better it runs.

JR

[Ernie]

I finally got that nasty bolt out of the exhaust valve cover but now I can't seem to see the arrow in the peep hole when the line points to it's mark. I've turned the motor maybe 25 turns and still can't see the arrow.

HAAAAAAAAAAAAAAALP!!!!!!!!!!!

Ernie

[JR]

Take the spark plug out and it's a lot easier to turn and remember the slightest movement of the the engine will turn the flywheel with the timing mark a long way so take if slow.

JR

[Ernie]

Well, it's done! I found the perfect little wrench for that nasty bolt on the exhaust valve cover. I don't know it's name but its an open end on one side and a tiny 8mm ratchet on the other side.

Valves adjusted. Mixture set. When I crack the throttle it wants to fly.

Funny thing happened though...after I adjusted the intake valve the first time, it ran sort of ok then it got sluggish. I came find that the locking bolt on the tappet unscrewed itself and fell down into the exhaust valve cover. It still ran. What a forgiving little motor.

Who knows, maybe the Chinese will learn quality control some day and they'll have a decent product.

BTW, the exhaust valve was tighter than a $3 whore.

Ernie

[Ernie]

I just took it out for its maiden voyage after the new tune up and WOWEEE!!!!! It has twice the power as before and it even seems quieter.

Now if I can just figger out where these two 1.5" black sheet metal screws and this 1" by 5mm black machine bolt go, I'll be as pleased as a pig in poop.

They must go somewhere in the rear half of the scooter since all I had off was the seat, seat pan/motor cover, top case and the big plastic wrap around. The sheet metal screws don't bother me too much but I worry about a 5mm diameter machine bolt missing. I hope my butt doesn't fall off someday on the road.

Ernie

[JR]

LOL LOL!! Who knows it may have been an extra left by the Chinese in the belly pan that fell out!

Glad she came together for you Ernie and I just knew when you got that exhaust valve right she would do well, my 250B has 10k on her now and is starting to show signs of needing it again along with my wifes 250A but I'm going to wait until cooler weather!

Great job!

JR

[Ernie]

Only problem is it always stunk like gas when I pulled it in the garage after a ride. Now it is really strong. My wife is making me crazy over the smell.

Any ideas or is this just the way they are?

Ernie