Sluggish Acceleration After Prolonged Storage

[OAS313]

Hello All,

I’m reaching out for some help.

After a prolonged period of no use my smallfame needs a little tinkering. I’ve cleaned the carb of sludge from the old petrol and fitted new jets (same sizes as previous), cleaned the tank, cleaned the fuel tap and swapped the fuel line.

With fresh fuel in, it starts fine, ticks over fine and accelerates fine in first gear when the engine is cold and also up to temp. However, as you progress through the gears and rev range it becomes very sluggish, sometimes to the point where it cuts out when decelerating. When warm it runs better with the choke out.

If anyone has any suggestions it would be greatly appreciated.

The setup is as follows:
- Malossi 135 Cylinder Kit
- Vespatronic Ignition
- 4 gear kit (58, 54, 50, 46 teeth)
- Primary Drive 27/69
- SHBC 19.19 Carb
- 60 Choke Jet
- 45 Idle Jet
- 85 Main Jet

[Deleted]

If it runs better with the choke out I would suspect an air leak... 🤔

How long was it laid up for?

[jbcollier]

Fuel goes to crap very quickly these days. Use stabilizer and drain and run the engine until the carb is dry, dry, dry if the scoot will be laid up for a while.

If your hot idle is stable, then it may not be an air leak. Carefully clean the carb again. Check all the passages and pull the atomizer out and make sure it's clear. Blow high pressure air through all the passages and check where they exit to make sure they are clear.

[barnsleybill]

Just curious as to why you changed the jets - have you tried putting your old ones back in?