Am I understanding this correctly - the air/fuel mixture screw (beside the idle adjustment screw) when turned IN lessens air and increases fuel flow? Or is it the other way around?
I put an aftermarket air filter on and it made the air/fuel delivery goofy...so I turned in the screw I'm referring to and I've got it bottomed out before the motor runs better. I'm thinking too much air with the aftermarket filter?
Ok. thanks - thought I was thinking and reading correctly, but I also didn't think the jet size has any bearing on low to mid idle circuit. I could understand WOT not responding correctly, but it isn't running correctly even on 1/4 to 1/2 throttle.
I'd have to be well OVER 100 in jet size to get back to the 2 turns out factory or dealer setting....something's goofy about that....can't believe the stock box is THAT restrictive.
barndwellers_md wrote:Ok. thanks - thought I was thinking and reading correctly, but I also didn't think the jet size has any bearing on low to mid idle circuit. I could understand WOT not responding correctly, but it isn't running correctly even on 1/4 to 1/2 throttle.
I'd have to be well OVER 100 in jet size to get back to the 2 turns out factory or dealer setting....something's goofy about that....can't believe the stock box is THAT restrictive.
Isn't there an idle circuit jet as well? That would be the one that regulated the flow through the passage that is governed by that screw. I haven't cleaned a carb on a PGO in a while, but I'm fairly sure there is a separate idle jet. That said, there are going to be lots of things that will change with the aftermarket filter. I'd keep one. Grand Prix Motorcycles use an air box and they seem to do ok. It seems like an 'easy' alteration to increase flow. But it mostly increases noise, decreases fuel efficiency and, as you've found, makes fine tuning a lot harder. The engineers work hard at balancing the flow of air in and out of the crank case. Changing one aspect will alter this balance of parts from the crankcase, to the reed bock to the manifold to the carb. Turning a screw will not put this back in balance.
Thanks - I think you're correct about the slow jet.
Brandon - so did you end up with the liquid cooled block? I still can't make up my mind. If I did get the l.c. block - I'd opt for the gear change as well. I think I'll wait and see how yours turns out before I take the plunge.
He doesnt have the LC cylinder totally ironed out yet, but I have all the other components here. Ported 12Xcc cylinder, exhaust, 28mm carb, variator, clutch, flywheel, final gear, rollers, clutch spring...........and I guess thats it. I am pretty busy right now, so I am about to go drop the scooter and all the parts over at a buddies house so he can get it together. Give me about 3 days and I should have some feedback.
I am waiting on a second part of the package that has the intake tube and cylinder head. I am the same you, its a clamp on carb. Not bolt on, so the stock intake does no go. Should be here tomorrow.
The 26mm carb had a completely different setup - he sent me a different throttle assembly, but I think I'd figure out how to get the stock one to work.
barndwellers_md wrote:What about the throttle cable?
The 26mm carb had a completely different setup - he sent me a different throttle assembly, but I think I'd figure out how to get the stock one to work.
Well I have a new throttle cable and mechanism. I have to use it as you have a different hookup to the top of the carb and no splitter if you dont use the two stroke valve. ALSO, my I got an adapter that has the 2 bolt flange to mate with the intake tube. It no worky. The holes arent close and even if they were, the intake tube OD size is smaller than the outbound carb ID size. HUGE mismatch. To top it off, If you were to mount the 28mm PWK carb where the intake tube ends, you would have to have a gnarly notch in the seat bottom to clear. Not an option. So i am going to make a new intake tube and extend it about 4" further out. That will get me plenty of overhead clearance. I am going to make the tube without a 2 bolt flange and just run butt to butt with the carb with a female receiver coupling. Next, I didnt get a new head gasket, so I am going to try and find a piece of .045 copper and make one. Plan was to have it running by the weekend, but that may be a stretch. Since I am going to have to machine a new intake tube flange, I am going to make a block off plate for the two stroke valve as well. That and removal of the exhaust accessory tube will really clean things up. I will keep things updated.
I had a hunch the intake tube/carb fitting was going to be an issue. If you happen to think of it...could you snap a pic of the tube/carb area once you get it together? 4" extra sounds like a mile. Hope the process goes smoothly for you.
brandon75173 wrote:
Next, I didnt get a new head gasket, so I am going to try and find a piece of .045 copper and make one. Plan was to have it running by the weekend, but that may be a stretch.
Many kits are designed to work without a head gasket. I'd dry assemble with copper RTV and check the squish distance. If it's not smaller than 1mm then I'd try it as it is. If it's more than 2 mm, I'd check where the ports are opening and possibly make an aluminum base plate instead (still using just RTV at the head).
Come on, anyday now Scooter works !!!!!