Imagine my disappointment

[Malisaw]

Oh well....

Got about 16,800 miles or so on the Speefight 2 -- after all I've done with it I still have problems with the low end take off...and up to 5 mph or so. I decided the only thing left was the reeds... so I bought a new reed block and some polini carbon fiber reeds to replace it with.

Got out yesterday to work on it, got the old reed block out (expecting it to likely be the original metal ones)...not. Went ahead and replaced it with the new one which, of course, made zero difference.

The scoot runs great once it starts moving (or giving it full throttle off the line). Strange thing, that makes it difficult to diagnose IMHO, is that as soon as I get to about 5mph I can drop the throttle back to like 1/16 to 1/8th and it will just cruise happily up to 30-40 easy as you please. I can easily make it to 50mph with less than 1/2 throttle - top end is about 53..but don't really need full throttle to reach it. (Full throttle does give a slightly deeper more pleasing sound though).

Even on the stand at idle there is a huge delay in throttle response if I go to like 1/8-1/4..delays and sputters a bit for second or two then goes.

I would look to the pilot jet, except the plug chops check out fine. I really tend to think it needs a much smaller pilot check from the behavior (especially climbing so high in speed with such little throttle...after it starts moving that is...lol).

Been through the rollers, shoe springs, clutch springs, etc. etc. Also...it was very responsive off the line before the areche carb...which again points me back to the pilot jet....which seems dang hard to find over here in the UK (not even sure what's in there now..what it shipped with or what to try to replace it with).

Anyone have any ideas or questions to guide me down the right path -- I'd sure appreciate it. I love the perfomance other than that bog bog BANG WE'RE OFF! Forgot to mention (not sure it matters, but just so all the info is out there)... Given a nice steep LOOOONG hill..if it's long enough..I can still hit 50mph....40 is easy, 40 to 50 takes awhile going up hill. (I do mean a fairly steep hill..moderate inclines aren't really noticable)

[Zuma-Zuma]

I would have started with stronger clutch springs. Second, and since I don't see anything listed, would be airbox modifications. Do you run stock, foam? I've seen people wrap tape around the airfilter until the bogs go away. Sometimes the foam just won't work right except at top end, WOT. They tend to be goofey in the mid or off the bottom. Since you have that many miles on it, I would check crank seals, and case seals just to be sure.

[Crazy Scooter]

I had the same issue with my aerox at 5350 miles and the problem was the original owner had not run the bike in properly and had a single point siezeup at the exhaust port. Replacing the piston and cylinder cleared that up for me. It ran great except at startoff, high end was fine tho. If you do go that far be sure to change the smallend bearing at the very least and I would recommend the crankcase seals also.
Hope this helps
o_o

[Malisaw]

Thanks for the reply!

I would have started with stronger clutch springs.

I have been through all three clutch springs (got a white/red/blue one with the Polini Variator kit)... I went from weakest to strongest (twice...during initial install of the variator...and after the exhaust/shoe springs/carb/belt/rollers were all done I tried them all again for good measure). The blue one appears to provide the best take off and is a noticeable improvement over the white and red.

Second, and since I don't see anything listed, would be airbox modifications. Do you run stock, foam?...

I did have a TNT Vortex air filter on there...but the thing clogs up in the rain so I had to take it back off. (Just made more noise anyway, not really an improvement which suprised me..given the increased airflow over stock). I've gone back to stock, with loads of holes drilled. Have also tried running it down the street with no air filter/air box at all --> sounds like a chain saw in a 55 gallon drum..but takeoff behavior was pretty much the same.

Since you have that many miles on it, I would check crank seals, and case seals just to be sure.

Now that could very well be....I'm a bit hesitant to mess with that right now, not ONLY because I have no clue what I'm doing...but the weather is miserable here and I have to work outside. I might look at doing that when the weather warms up a bit. Was also wondering about carbon/whatever buildup... but I keep reminding myself that the low end issues started when I put the arreche carb on.

I replaced the electric choke yesterday just in case... which, interestingly, required me to reset the idle/airflow screws (which I'll be playing with more over a couple of days to get set right again)...but still the takeoff behavior is pretty much the same.

Appreciate the suggestions! I'll check out the seals during nicer weather... or I may just opt to try this performance 50cc cylinder I've been eyeballing.

Can't go to a 70cc over here as it requires you to reregister your scoot and go through a certification process (costs about 300 pounds... $500 or so! and they could easily decide to fail it).

[Malisaw]

I had the same issue with my aerox at 5350 miles and the problem was the original owner had not run the bike in properly and had a single point siezeup at the exhaust port. Replacing the piston and cylinder cleared that up for me. It ran great except at startoff, high end was fine tho. If you do go that far be sure to change the smallend bearing at the very least and I would recommend the crankcase seals also.
Hope this helps
o_o

Thanks for the reply Crazy. That points me back to the 50cc racing cylinder replacement kit I've been eyeballing anyways... I've just been hesitant to do it because I know at some point in the not to distant future I'll be going with a 125cc something or another.

Smallend bearing? You lost me with that one! Checked my Haynes manual and don't see anything called that...can you give me a little more info on the Smallend bearing?....where is it?

Thanks for the help!

[speedy_scooter]

If you are running a stock airbox with a bunch of holes that can make you run lean. I'd say cover up all those holes and try again.

[Zuma-Zuma]

You can always go back to the stock carb. I just re-read your setup, and you have the stock 50cc cylinder yet? If so, then yes, you may lose some bottom end with the bigger carb. Less velocity will cause some lag. Usually its made up on the other end. I've seen the stock carbs work well with 70cc kits, so it should be good with a 50. Maybe some jetting on the main, but not too far. Sorry I didnt' catch it till now.

[Crazy Scooter]

Hi Mate,
The smallend bearing is where the conrod attaches to the piston. If you remove the piston gudeon pin you'll see it in the conrod hole. The main bearings are on either end of the crankshaft and changing them requires splitting the case. Big end bearing is where the conrod meets the crankshaft, if that ever fails you're best replacing the crank as most of them are pressed together and balanced in the factory. Changing the seals should be possible without doing an overhaul and they're only 4 quid each roughly, you will need a strong hooklike screwdriver device that can be purchased from a snap on dealer or something. Regarding the 70cc kit, if you're a safe driver and stay within the speed a 50cc would do whenever near the cops i'd do it in a heartbeat. Most of us are totally illegal with our race only pipes and all our upgrades so whats another item on the list gonna do, even if you went for the sva test to be compliant you're still gonna have a ton of hassle with the insurance company as its not standard. In the end what they don't know about won't hurt them and how many cops are going to pull you over and make you disassemble your motor in front of them for a bore measurement, I'm 99.9% positive none of them will ;) I've upgraded from the standard 101cc to the 125 bore and all i get is better acceleration and better upwind performance.
Good luck with it o_o

Thanks for the reply Crazy. That points me back to the 50cc racing cylinder replacement kit I've been eyeballing anyways... I've just been hesitant to do it because I know at some point in the not to distant future I'll be going with a 125cc something or another.

Smallend bearing? You lost me with that one! Checked my Haynes manual and don't see anything called that...can you give me a little more info on the Smallend bearing?....where is it?

Thanks for the help!

[Malisaw]

Thanks for all the replies and the suggestions/advice from everyone.

I've decided to go ahead and do a 70cc kit. Only question I have left regarding that probably going to come across as a really stupid one...but having never done much with them in my life as a computer network engineer... :compp: I want to be sure I have all I need! The kit comes with gaskets, etc....and I'm going to go ahead adn spend an extra 20 some odd on a new cylinder head just because...well..it's there... And the haynes manual has a procedure for decarbinization of the cylinder head - pretty sure replacing it will solve that little issue , lol.

Question -> Gaskets... do I need any type of gasket sealing compound? I noticed on the site I'm purchasing from that people that bought the cylinder kit also purchased some kind of liquid silicone gasket or something -- I just don't want to get in to this and not have what I need...being on a 5x9 mile rock I'm pretty limited on supplies on the island, so if I don't order it now..I'll be screwed for awhile.

Just as a side note -- all the work (in my signature) that I have done has been approved by the folks at the local DVR (that test the bikes/scoots) as well as my insurance company. Basically I have been told, and have in writing, that as long as the products (exhaust only) is EEC...and as long as I don't change the actual size of the engine from 50cc's.... I'm permitted to change the clutch/rollers/variator/carb/exhaust, etc. --> providing I have a license for a 125. If I change the cylinder and up to to 70cc then I have to notify the insurance company and will have to have the bike reclassified (about 300 pounds or so). I'm just not gonna bother telling 'em. I figure as long as I don't total an Aston Martin DB9 or something similiar then they aren't gonna check my piston!

I've also warned the wifie that if she isn't going to let me buy my Hyosung Aquila 125 then I'm going to keep pouring money in to this scoot until I blow the thing to bits. :naught:

[XPS1210]

The airsal (and all the others I know of) come as a cylinder kit...

meaning, you get the cylinder, piston, circlips (to hold the piston in place), head, all gaskets, some come with new wrist pins, and wrist pin bearing... and most come with a new spark plug...

you don't need gasket sealer.. simply pull the stock one off and replace with the new one... The ONLY thing that I suggust you do... is coat the piston, inside of the cylinder, wrist pin, wrist pin bearings with a good coat of 2 stroke oil... synthetic is best (IMO) but regular 2 stroke oil will work... this way it's lubricated with oil and not going to damage anything when you first start it...


as for your insurance... I don't see 1, how it would effect the insurance rate as long as it's not registered as a "moped" which is usually limited to 30 mph or less... 2, not like they could tell anyway, it's not like they'd take the cylinder off and measure...

[Malisaw]

Thanks Jered! This is a kit - I am more interested in low end torque than doing much more with my top end so I am going with the Top Performance (The Airsal isn't available, the DR on the site I get stuff from over here doesn't include the cylinder head...the TP is just the same exact thing with the cylinder head included). Guess I'm all set -- thank you for the very quick response..I was hoping to get this ordered today because it'll take a good week and a half+ to get it here.

I have no doubt I'll be getting some grease on my keyboard as I try to do this and come back here to look things up about 50 times!

It says an awful lot about your site when a guy 4,800 miles to the east of the US, riding a scooter that you really don't deal with, still finds THIS site the absolutely best place to come for information!

How cool is that?!?! :worship: :worship: :worship: