Jetting standard 200/basic upgrades

[Stebbelaner]

Hi all,first proper post,asking for advice please.
Took my Serveta 200 on its first proper ride today and it heat seized when I was taking it to
near full throttle on and off for 15 minutes riding.Luckily no lasting damage and I rode home when it cooled down
As far as I'm aware it's a standard 200 cast iron barrel & piston with a 42mm AF Clubman,Breathe Sweet type foam filter ( no airbox) and 20mm Dell'Orto carb.
Any jetting/ carb settings advice for the above set up would be appreciated to hopefully prevent future repeats.

[Daggs]

If you have experienced a 'heat seize' your first course of action should be to remove the barrel and piston for inspection. If the rings are smeared into the piston, jetting changes alone will not resolve the issue.

[Stebbelaner]

Thanks,but if that's the case and new piston/rings/rebore are required then no point rebuilding it with the same carb set up.
Just after some base settings for standard carb using a clubman and foam filter?

[cgt75b]

Here ya go fella

Slide - 5914 - 1
Atomiser - 5899 - 2
Main Jet - 103 - 123
Pilot - 45
Starter Jet - 50

I hope that helps and you get it sorted

The very best of luck

Regards

Cgt75b

[Warkton Tornado No.1]

Your carburettor may well need to be richer, but....

Time & again Lambretta riders fall into the trap of thinking the engine is something akin to a car, four stroke, water-cooled engine.

For a start, they add extra two stroke oil. That WEAKENS the air/fuel mixture.

They do not let the engine rev. Not only does that labour the engine but low revs means low cooling! The fan is the only means of lowering the temperature of the cylinder.

If they feel a heat seize is imminent, they stop & switch off the engine! Far better is to declutch, thus removing any load, & keep the engine going (not screaming!) to cool the assembly down. Trying to add a touch of choke will also richen up the mix whilst the engine is then nursed back to something like tick over.

IMHO it would be far better to cane an engine than apply some peoples' interpretation of running in.....

[nick b]

i had a set up from af watford a 225 stage 4 a30 mil dellorto aND big bore every time I opened up a heat seizure Ray Kemp at the time said smooth out the Barrell with emery cloth , eventually I had it bored out to 230 ,witha bultaco piston and skimmed head by Dave Webster ,never another problem,this was about 40 years ago the problem was the bore not the jets

[nick b]

i had a set up from af watford a 225 stage 4 a30 mil dellorto aND big bore every time I opened up a heat seizure Ray Kemp at the time said smooth out the Barrell with emery cloth , eventually I had it bored out to 230 ,witha bultaco piston and skimmed head by Dave Webster ,never another problem,this was about 40 years ago the problem was the bore not the jets

[Stebbelaner]

Thanks all,I'll check my carb settings and adjust if necessary then maybe ride slower