New Spaco 24/24E - Are there any inherent proplems

[paulwaite]

This project is far down my list and it gets done when I can find time.

Its the Rally 200 engine that has appeared in other threads. But after a complete strip down, it's now OK and transplanted into a GS160. However, as part of the re-build, I replaced the unfix-able leaking Spaco carb with a new one from Beedspeed (& I see  sime66 has had issues). Anyway, engine fired up quickly yesterday and did a few runs up and down our lane. Trouble is it four strokes immediately and will not rev out. Checked all jets and they are what the original spec shows. Air mixture screw is 1/2 turn out as i understand that it gets richer the more turns out. And from what I have read, the 55/160 starter jet controls the revs upto around 1/2 way.

Now in my Lambretta world, Jetex have a bad name, but I've never had an issue. But do the Spaco carbs have some inherent defect that I can put right?

One other issue is that the fuel in the tank may be 2 years old, but I cannot see that really being the problem in it 4 stroking!!!!! 

Thanks

Paul

[henri]

2 year old fuel , dump it , without the preservatives/additives nowadays it goes off after 3-6 months .cant see it 4 strokeing but to rule it out dump n flush . an yes jetex are 50/50 ,either work out the box or crap . spaco's are made in the same factory as dello'rtto's ,dell dont make in italy but under licence in india by spaco. theres always the suspicion the spac's are dell's that didnt pass quality control . but in my experience theres no difference in quality or lack of it . both need lookin at or fettling before fitting.
the pilot jet controls upto 1/4 throttle but still provides thru the range , if screws only half a turn out sounds like over rich pilot , should be more like 1 1/2 turns out . H

[paulwaite]

Thanks Henry. Did drain tank and put new fuel in, but still the same issue, see below that i have also pasted on the Scootererotica site.

Engine fires up easily and ticks over OK once the choke is pushed in, but will not rev out and has no power and appears to be running rich in the way of smoke and 4 stroking.

On the carb side and this is a new 24/24E Spaco carb, all jets are standard for this engine. Air mixture screw makes no difference and neither does jetting down the starter jet, or running with air filter off. I've also removed choke wire to make sure that the choke is fully in and fuel delivery is also OK. Suppose I could change carb, but last night, between 2 and 5am, I got to think about the piston and did I put it the right way up

On the electrics side, all stator resistances Ok and change of CDI unit, HT lead, cap and spark plug make no diffrence.

Now I'm sure that I put the piston the right way round, ie, arrow pointing to the exhaust port. But there again, I get distracted and things go on differently. So what are the symptons of the piston the wrong way up, are they as I have described.

[vespasco]

you'd be lucky to get it running at all
someone here managed it with a the help of a big hill i seem to remember

please check your gear box oil for signs/smells of petrol

[paulwaite]

Oh dear. Did change my clutch side oil seal, not that there seemed to be anything wrong with the one already there. But the one that I put back was an original Piaggio seal with the metal edge. Since then I have seen comments that in the Piaggio factory, these seals were driven in and cannot be done the same in my garage. Therefore, putting back an original seal, even with loctite, may still result in a leak.

One last thing to do is swop my carb and if this fails, I'll keep sniffing the gear box oil.

[henri]

balls ,if piaggio can drive em in so can you , ive got a really big socket i use ,but have resorted in past to using a smaller socket an working round the edge .a smear of loctite an not had a problem , the difficultys are if seals spun an damaged cases ,or crank catches inner edge as assembled . H

[paulwaite]

Must say that I did drive it in with a socket and it was tight. So I'd be surprised