Spree bogs/cuts out when fully throttled from stop

[Kevinstonge]

Hi guys. I'm putting a spree together out of all the extra spree parts I had laying around. It's an 86 spree with an 84 engine. When the engine was in the 84 last summer, it ran great and at a consistent 27mph, but I couldn't get the idle perfect.
Now that I've swapped the 84 engine into the 86 I'm having some issues dialing the carb in. What I'm experiencing now is a great idle and throttle response, but when I give it wot from a dead stop, it will rev up and sound good for 3-4 secs then bog down and eventually die if I don't back of the throttle. However, from a stop, if I ease onto the trottle, and open it gradually, it will accelerate to 25-26mph, and I can then hold wot with almost no cuts or skips in rpms. At first I thought an air leak so I re cleaned the carb, re secured the bystarter, and put new o-rings in the manifold spacer. Please share Any thoughts or experiences with this issue. I have not plug chopped yet cuz I'm waiting on a new plug, but when I pull it after a quick drive it looks chocolate brown and the slightest of wet. Petcock it in working order and clear fuel lines show plenty of fuel. Engine is all oem.
Carb has
68 MJ
Clip one down
Needle is a 76p I think( fatter than the 86 needle)
Mixture screw 1.5 out

Thanks all!!

[Johnniespeed]

Is the stock air filter housing in place ? Did anyone drill holes in the housing ? Is the rubber elbow fitting correctly ? Is the filter in place ? Is the filter lid in place and the screw in place ? Is there a gasket between the air filter lid and the air filter housing ?
I have resurrected over ten sprees from basket cases, barns and junkyards, and my questions above reflect the results of getting every one of mine running correctly.
If it sounds like I am harping on a perfect intake system, you are correct, those little sprees are fussy in the air filter department.

[Kevinstonge]

Is the stock air filter housing in place ? Did anyone drill holes in the housing ? Is the rubber elbow fitting correctly ? Is the filter in place ? Is the filter lid in place and the screw in place ? Is there a gasket between the air filter lid and the air filter housing ?
I have resurrected over ten sprees from basket cases, barns and junkyards, and my questions above reflect the results of getting every one of mine running correctly.
If it sounds like I am harping on a perfect intake system, you are correct, those little sprees are fussy in the air filter department.

Yes, no, yes, yes, yes, and yes. I agree, the airbox is very finicky with the sprees. It's worth a double check, but as far as I know the airbox is in perfect working order.

[patthesoundguy]

The air cleaner element needs to be oiled to the manual spec or it won't runt right at all. Go over the airbox and the air hose to the carb with a fine tooth comb, make sure the clamp on the air hose is good and sealing right. Now I would possibly bake the exhaust. If the plug is wet then it could be running rich from a clogged up pipe or a malfunctioning bystarter. There is a vacuum test in the manual. Also the needle clip needs to be in the middle position. If you don't have a vacuum tester you can use an ear syringe from the drug store like this

Of course the test is done with the carb on the scooter. That port on the carb intake will pass air when the scooter is cold and won't pass air when it's hot if I remember correctly. That confirm the bystarter is working correctly and not stuck in enrich mode all the time.

[Kevinstonge]

Thanks pat. I'll check it tomorrow.

[tazland001]

The air box is deff a good place to look. Hey pat that looks like a snot sucker. lol

Taz

[Kevinstonge]

Thanks guys. Double checked airbox and everything was SAT. Then checked the by starter for 12v while idling- UNSAT. No voltage at all. Is the bystarter wired directly through the ign? I'll check the schematics on my break, but if someone's already knows, please share.

[Wheelman-111]

Greetings:

Mousewheels once posted that the bystarter runs A.C. like the headlamp not switched DC. That way it won't start heating up until the engine runs. Makes sense if you thinaboudit.

[patthesoundguy]

Yes ac voltage and its yellow and green wire in the harness. I think the yellow wire also feeds the headlight. Along with the vacuum test you should just touch the bystarter leads tobtue battery and see if the needle moves out. You can also pull the bystarter when the motor has been running for a while the needle should be in the out position
I'd the bystarter moves in and out the vacuum test is needed to make sure its actually sealing the port as it should when it moves out

[Kevinstonge]

Tested for ac voltage a found some. Also I bench tested this bystarter before installation and the needle moved as it should. I would've vac tested the bystarter port like pat said, but I don't have an ear syringe or anything similar.

I then swapped the needle(76P) out for the one in my 86(5SB), and all is now well. Zero bog throughout the rpms when WOT from a stop. It feels like it may be on the lean side a little, but a plug chop should tell me what I need to know. Won't be raining tomorrow so I'll be doing that then.