d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 8, 2013 21:31:59 GMT
I have recently posted here about installing a new SIP exhaust on my new PX125. So far, with your help I have fitted the exhaust and rejetted the carb. I have also drilled out the airbox. Apparently I now need to adjust the fuel mixture. I think the screw I need to adjust is just at the back, near the bottom of the carb. I can see it, I can touch it, but I'm blowed if I can get a spanner on it to turn the screw. Actually it's not screw, but a nut! There isn't enough room in the space to get any turn on it. Is there a secret to it, or will I have to take the carb off to get at it?
|
|
mickymidas
High Number
2Ronnies sc , Nuneaton.....Promoting chuckleism to the masses
Posts: 232
|
Post by mickymidas on May 9, 2013 7:33:23 GMT
I think there is a post on here somewhere on the same thread . I seem to recall that if you have an elec start , the motor gets in the way, but it is do-able. if not a 7mm socket with extension should do. Have a look at other carb related threads and you may come across it.
Hope this helps .....Mick
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 9, 2013 9:16:51 GMT
Thanks Mick,
Will have a look for that post. It's frustrating that the design of the scooter seems to make what should be straight forward jobs into something more complicated! In this case the elec motor being in the way and also when I took the exhaust off all went well until the bolt holding the exhaust to the frame, Came out easy enough...until it hit the rear tyre! After much head scratching I decided to just let the air out and then squeeze the bolt out.! Grrrr
|
|
mickymidas
High Number
2Ronnies sc , Nuneaton.....Promoting chuckleism to the masses
Posts: 232
|
Post by mickymidas on May 9, 2013 11:29:33 GMT
In the past I have found that a 17mm ratchet spanner to undo the exhaust bolt then molegrips to pull it past the tyre works .......it rubs against the tyre a bit but comes out with a bit of wiggling about .
I have recently fitted a SIP Road to my scoot and think it's a good buy.
|
|
mickymidas
High Number
2Ronnies sc , Nuneaton.....Promoting chuckleism to the masses
Posts: 232
|
Post by mickymidas on May 9, 2013 12:10:01 GMT
" Borrowed" this off SBW, might help......
" i got a cheap 7mm spanner,heated the open end up and bent it at a right angle.its still fiddly but i can turn it a quarter or half turn at a time.""
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 9, 2013 13:15:30 GMT
" Borrowed" this off SBW, might help...... " i got a cheap 7mm spanner,heated the open end up and bent it at a right angle.its still fiddly but i can turn it a quarter or half turn at a time."" Thanks again Mick If all else fails I might try this. The screw only needs a quarter turn at most! |
|
|
|
Post by pxguru on May 9, 2013 16:56:21 GMT
For what it's worth here is what I do! Take out the whole screw. Put it in a vice. And cut a screwdriver slot in it !! Happy twiddling  |
|
|
|
Post by sbwnik on May 9, 2013 21:45:07 GMT
" Borrowed" this off SBW, might help...... " i got a cheap 7mm spanner,heated the open end up and bent it at a right angle.its still fiddly but i can turn it a quarter or half turn at a time."" SBW... the home of high quality bodging. You can tell why it's my home  Socket and flex joint will do it, but I don't see why you'd need to richen the mix, the bigger jet does that. |
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 10, 2013 8:32:41 GMT
Hi sbwnik, I'm not sure if it's the mix screw that need adjusting or not, but from the top I have fitted a SIP road pipe and upjetted to 102. I have now also drilled out the air filter  But the scoot is running a bit "rough" I don't know anything about the mechanics, I just like to ride'em. What do you reckon? |
|
|
|
Post by sbwnik on May 10, 2013 10:36:46 GMT
Normal question, where are you?
Rough doesn't really tell anyone much, is it bogging at low revs?
|
|
|
|
Post by sbwnik on May 10, 2013 10:38:49 GMT
Thinking about it, 102 sounds bloody big to me? I'd have thought 98/100 at the most?
Standard is 96, isn't it?
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 10, 2013 10:58:55 GMT
I'm in Devizes. Wilts and yes bogging down at low revs seems to describe it. Once I get going and the revs are up it's ok. Only fitted 102 because the guys I bought the pipe from recommended it. But I think you are right, 96 is the standard. Perhaps I should try 100 and see how that goes!!
|
|
|
|
Post by sbwnik on May 10, 2013 13:39:22 GMT
If it's bogging low down then it's running rich (99% of the time).
Check how far out the screw at the back of the carb is turned out before you do anything. Wind it all the way in (anticlockwise) and then count the turns back out again. It's generally 1.5 - 2 turns out - ish.
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 11, 2013 14:13:17 GMT
Hmmm, swapped the jet to a 98 and it's still bogging down at low revs. Plug looks a bit wet.
|
|
|
|
Post by kru251 on May 11, 2013 15:13:01 GMT
PX125 with std exhaust etc
Dell'orto carb
20 carb (venturi size)
96 main jet
45 slow running jet
140 air corrector jet.
I had to go up a couple of sizes of main jet when I used the drilled out air filter on my 2001 PX200. That equates to your 98 you have fitted now.
Choke is not sticking on a bit is it?
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 11, 2013 20:45:51 GMT
Don't think it's the choke sticking. I really don't know what else to do with my very limited knowledge. Maybe time to take it to someone who knows what they're doing!
|
|
|
|
Post by sbwnik on May 12, 2013 4:08:35 GMT
Screw the mixture screw in, counting turns as you go. Any more than two and it's shaken itself out over time. Wind it back out to two full turns and see how it feels. Any less, set it back to where it was.
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 12, 2013 10:38:30 GMT
Screw the mixture screw in, counting turns as you go. Any more than two and it's shaken itself out over time. Wind it back out to two full turns and see how it feels. Any less, set it back to where it was. That's not so easy as I can't access the screw (nut) properly because the elec start motor is in the way |
|
|
|
Post by kru251 on May 12, 2013 18:25:08 GMT
" i got a cheap 7mm spanner,heated the open end up and bent it at a right angle.its still fiddly but i can turn it a quarter or half turn at a time.""
As stated above.
I have a 'special' 90* 'bent 7mm' too that I made for this job as you are quite right that the electric start does get in the way.
|
|
d00dge
2nd Class Ticket
Posts: 33
|
Post by d00dge on May 12, 2013 20:27:28 GMT
So how did you heat it up? Just put it over the gas hob?
|
|
|
|
Post by kru251 on May 13, 2013 9:44:54 GMT
In metal bench vice. Used a blowtorch then tapped it over. If you find a cheap pressed steel type which is thin then these can be tapped over with a hammer cold!. They aren't very strong, but how much effort is it to alter that mixture screw a tad? It's not like you do the job all the time!!!  |
|
|
|
Post by baldmeister on May 13, 2013 18:12:56 GMT
hi, i always use a pair of long needle nosed pliers to turn the mixture screw, you only want to turn it a little at a time after all!
|
|
|
|
Post by sbwnik on May 13, 2013 20:44:47 GMT
Screw the mixture screw in, counting turns as you go. Any more than two and it's shaken itself out over time. Wind it back out to two full turns and see how it feels. Any less, set it back to where it was. That's not so easy as I can't access the screw (nut) properly because the elec start motor is in the way Pull the starter off and chuck it in the bin, it only slows you down anyway  |
|
|
|
Post by kru251 on May 13, 2013 21:45:53 GMT
hi, i always use a pair of long needle nosed pliers to turn the mixture screw, you only want to turn it a little at a time after all! Aaaaaaaaaaaaaaaaaaaagggggggggggghhhhhhhhhh. |
|
|
|
Post by sbwnik on May 14, 2013 20:25:00 GMT
I don't see the problem with that, though it's not ideal.
Why the hell did they stop putting screw heads on the adjusters just when they changed the design so that you would need one?
|
|
|
|
Post by kru251 on May 14, 2013 23:40:30 GMT
I don't see the problem with that, though it's not ideal.A complete anathema to me as an ex aircraft engineer!!!!!! 
|
|
|
|
Post by sbwnik on May 16, 2013 20:10:04 GMT
Ah.... This is a Vespa we're talking about.
It's good enough.
I remember when we used to set points with ciggy papers....
|
|
|
|
Post by kru251 on May 16, 2013 20:24:22 GMT
No issues with ciggy papers; they aren't butchery as pliers on screws are |
|
|
|
Post by sbwnik on May 16, 2013 21:48:43 GMT
Pah, we'll never make a scooterboy out of you.... Plug spanner, two screwdrivers, two pairs of pliers, mole grips and an assortment of metric and imperial sockets.... My early toolkit I also used to have a conversion list of imperial to metric socket sizes for when you rounded off a head - next imperial size down could usually be encouraged to go on to the rounded bit and grip. Ah, the 80s. I miss them. |
|
|
|
Post by kru251 on May 16, 2013 23:09:41 GMT
Well about 60% of all my substantial toolkit is Snap-On. Fatal to have the van rep come round every week and let you have stuff "on Tick". Kept me a poor apprentice but I still have them after 35 years so can't be bad.
SBW Nik - cynical about his scooters since 1982, but still refusing to give them up as he hopes one day one of them will prove him wrong.
That's the eighties for you Nik
|
|
