Modern Vespa

Good call.

Give the fuel line a wiggle, try moving it in or out of the frame an inch and see what happens.

Will do. I am out of runway for the day…
(Need to be working on the SS and not this beastie.)

More tomorrow.

Now that we're on to a possible fuel line issue, i'm curious as to what sort of hose you're using for the fuel line?

He needs a Vanilla (no kink) fuel line.

https://www.scootermercato.com/Scooter-Parts/Fuel-Taps-and-Parts/FUELLINE

that green crappy hose shouldn't even be sold. Find something else.

This one is MUCH better.

I've been slowly going away from regular taps and green fuel line. It turns hard as a rock in 6 months, and I've replaced two that were pinched a bit.

^^^^x10!

Tygon (that yellow colored fuel line) is a great fuel hose, but not for our application. So pass on that as well. It will kink way too easily when routed to the airbox.

Stay on target!

Don't jeopardize that sweet, sweet ham slice!

All of this.

*pokes more pins into P2 voodoo doll*

*laughs low evil laugh*

they suspect nothing.. NOTHINGGGG!!!!

F#$ker.

Fancy pantsy fuel line ordered. Will see if that helps. (On quick inspection I didn't see any kinks,)

gotta protect that ham slice investment!

Fancy pants fuel line made no difference.

Set the timing back to 18 or 19 no help.

Threw on a known good carb, no joy still running hot. 300 after a mile 350 after 3 or 4 miles.

So next things to try…
1 Cdi?
2 another stator?
3. New airbox?
(The one on there was rebuilt.)
4.?

All spitballs welcome!

Remind us what your jetting is, again?

4 is clearly profit, duh

160
BE5 (have tried BE3)
125 (have tried 130, 128, 122, 120)

what's the idle?

maybe you're cruising around more in the "idle position" of the fuel delivery band and it's not quite on the main so it's getting hot?

Without pulling it…
50-160
Or
55- 160

Are we sure we are air tight?

^^^^

Hmm
Unknown.
Don't have the BP tester thingy.

https://www.amazon.com/Adult-Dulex-Aneroid-Sphygmomanometer-Professional/dp/B082CZ3GHQ/

I like this style of ball and gauge because they are connected and you don't have to get a fitting set up to put the gauge inline.

Then all you need is an old bicycle tube and a thick piece of scooter tube for the base of the carb.

I'm telling you, this has saved me so much hassle. Twice it's caught leaks at the base gasket, and once at the carb box, and also the fly side seal...

I'll never put another engine together without doing this test....

Well... there was probably a small air leak. I'd love to say I finally made an airleak tester, but... I didn't make an air leak tester. Nay. I popped off the cylinder head and low and behold we had oil evidence. Lapped the head, added high temp gasket sealant, and closed it up. Also double checked timing.

Final result... running 50 degrees cooler at least.

Did 10 miles WOT and max was 254f averaged about 238f. Second neighborhood run 20 minutes later of 5 miles or so... with lots of stop signs, lights and idling... got up to 272. But, overall much more reasonable than the 300+ degree temps I had prior.

I will say that compression testing does seem pretty worthless. Comp tests didn't detect a leak and I tested the jug a few times with no loss of pressure. (One day, I will make a damn air leak tester.)

Compression test is only to check your ring sealing, won't catch a leaking head unless it is huge

Excellent BN - I'm glad to hear it!

Well done!

Time for Greasy to get his voodoo doll back out.

🙂

Shh shh. He's distracted by other things. Do not wake.

Thanks for the help all.
Going back up for sale now.

I've got my assistant working overtime.



now that you've sorted that, on to his next assignment...
*spins the wheel of malady and malarkey*

Well done!