NQ50 87 spree 16 MPH WOT HELP!

[robsnyder20]

Hello Guys, I need your advice on what I can do. I bought a scooter that hasn't been running in years from a friend and got it running. It seems to run good, idles smoothly but is really slow. I know this one used to go 32 MPH or so but I am only able to get it to go maybe 18MPH with a wind. I am a bigger guy 275 lbs but not sure if thats it or whats going on with it. I already swapped the carb with a new one off ebay for $80 and not sure what else might be going on. Belt seems ok and it just barely seems to go faster once you hear the centrifugal clutch kick over. I took off the muffler and didn't make a difference in it running and seems to be getting plenty of fuel when taking off the gas line. Any ideas, please help as I feel like I am going to have to settle with 16 MPH

[Johnniespeed]

I know you said you took the muffler off and it didn't make any difference, but I still don't trust that muffler, what I do on all two strokes is to cook the muffler in my gas grill for an hour, I place it so the inlet and tailpipe extend out the sides of the cover, cook on highest setting and I blow compressed air into the inlet, or the tailpipe every ten minutes, when all the smoking stops the muffler is done. By the way, this will smoke more than you can imagine, from years of caked on oil inside the muffler.
That 87 should be able to go faster than 30 with a 180 pound rider.
They say the drive belt width has an effect on top end speed also, but I don't remember the belt width measurement, perhaps someone else will chime in with that information.

[MrJumps]

Your clutch shoes could be glazed over, or you belt is worn.

[tazland001]

If you can blow thru the muffler with no restriction good chance the muffler is good. Since you took off the muffler we can rule any muffler problems out. So the next step would be to check for carbon build up in the cylinders exhaust. This is a common problem. You need to poke the carbon out but be gentle. See if that works.

Taz

[robsnyder20]

Thanks for the advice, going to try those things to see if I can get it running any better. I did check the belt last week and looked ok and didn't appear like it was slipping but who knows. It appears I can get a replacement for like $10 thats a little wider than the original anyway that should help things along.

[tazland001]

keep us updated.

[patthesoundguy]

What scooter model btw? The trick is here to figure out whether this is a motor issue or trans issue. Does it rev up or stay bogged down. Hi revs only going 18 mph says trans. Low engine speed at full throttle, not likely a trans issue.

[robsnyder20]

It seems as if she's not revving up properly. It just seems to have about 1/2 the HP she should be making. How hard is it to replace the pistons and redo the top end? I see kits on ebay going for $45 on up but not sure if its difficult to do or not. I actually got a new NGK plug and gapped her properly but only getting about 15 MPH out of her and is sluggish to accelerate to full speed.

[MrJumps]

It seems as if she's not revving up properly. It just seems to have about 1/2 the HP she should be making. How hard is it to replace the pistons and redo the top end? I see kits on ebay going for $45 on up but not sure if its difficult to do or not. I actually got a new NGK plug and gapped her properly but only getting about 15 MPH out of her and is sluggish to accelerate to full speed.

Rent a compression tester from autozone and test compression before you go rebuild, also make sure you airfilter is installed, oiled, all gaskets are on tight with no leaks. Remove the plug and put a half a cap of fresh 2 stroke oil into the cylinder and put your tester on it, hold the throttle wide open and kick like 3 times. should read above 90psi, if not then check the seals on the crank for oil residue, put the scooter on its side and look for a bad case seal. Might be worth a try to take the plasticss off the engine cowl and look at the gaskets for leaks.

[edit]- Another thing that came to mind was the pet-* or fuel-tap, take the vacume line and the gas line off the carb and point the gas line into a cup and give a suck on the vacume line and see if it flows correct.

- Jumps

[motormike]

$80 eBay carbs have been known to be real crapola...and by no means tuned to perform properly on your bike.
Some people claim to have had good luck with them...I don't know first-hand.
I would give every possible effort to clean and rebuild a Keihin OEM carburetor before buying a clone from China.
I CAN say from personal experience that a clone carb I installed on my NS50F was twice as heavy as the OEM carb,
and did not run very well. The OEM carb was subsequently cleaned and re-installed which made the bike screaming wicked.
I have no additional diagnosis for your problem...

[patthesoundguy]

$80 eBay carbs have been known to be real crapola...and by no means tuned to perform properly on your bike.
Some people claim to have had good luck with them...I don't know first-hand.
I would give every possible effort to clean and rebuild a Keihin OEM carburetor before buying a clone from China.
I CAN say from personal experience that a clone carb I installed on my NS50F was twice as heavy as the OEM carb,
and did not run very well. The OEM carb was subsequently cleaned and re-installed which made the bike screaming wicked.
I have no additional diagnosis for your problem...

I don't think anyone has had any luck with the spree eBay carb yet that I can recall.

[patthesoundguy]

Is the air box there and hooked to the carb and clamped on? Is the air filter in good condition and oiled properly? Does the airbox cover have a gasket in it? No airbox will have a spree non operational or barely. It may idle fine but it will refuse to rev at all, but it may get going after some coaxing on the throttle but not well.

[patthesoundguy]

Thanks for the advice, going to try those things to see if I can get it running any better. I did check the belt last week and looked ok and didn't appear like it was slipping but who knows. It appears I can get a replacement for like $10 thats a little wider than the original anyway that should help things along.

I don't recommend installing the wider belt unless you want it to run worse. That changes the gear ratio and the scooter will have no bottom end take off without some decent modification. And installing that wider belt takes is a pain in the rear, and if not done correctly you run the risk of ruining the end of the crank shaft.