Modern Vespa

I am working on a 65 Allstate for a friend. I added a 177 Pinasco kit that appears to have some SERIOUS compression. The actual PSI I can not tell you at the moment, but can probably get that info tomorrow. If I pull the plug and kick it, the piston moves with ease, as it should. Plug in though, it feels like my SR500 single- you definitely have to put some weight into it.

I have gone though two (aluminum) kicker arms recently just trying to get this project finished. The teeth on the arms just can't hang with the force needed to start the scooter. It this point I am just trying to figure out what my options are. Does anyone make a steel kicker? Where can I find one?

Another option would be to have a thick copper or aluminum gasket cut for the head, increasing the distance between the piston and the head at TDC, thus lowering compression.

I also thought about machining the head to accept a decompression valve for use while starting this thing. What do you guys think? Any other ideas?

have a search if you can as this was thoroughly gone over last year

Thanks for the hint! So hopefully there is a light at the end of the tunnel. I found this one, and it was close, but not exactly answers I was looking for:

VBB kick start lever

This thread is making me think that the bolt that I used in the second kicker may have had something to do with it..... as it was threaded all the way to the head, however it was set to a very high torque. I'm not convinced this is the issue though:

kick start slipping

Edit: In reading that thread further I have seen that there is a company that makes a steel kicker (LML?). I will look into that further in the morning. Thanks for the head start.

you really don't want to do that. the first time that one slips, it will screw up the teeth on the kickstart quadrant. and then you'll have to split the cases.

You need to make sure that the lever is on tightly, and that the lever isn't bottoming out and closing up the gap before it grabs on tight. you may need to open up the slot.

i can't stress enough that the lever needs to be tight. if it has any play, it will take the teeth off.

+1

from personal experience

Get the proper bolt that's not threaded all the way to the head & make sure it's high strength. You need to have it REALLY tight as Rob said or this will keep happening. You probably have a plain mild steel bolt there now that you'll never get tight enough because it's stretching. Avoid a steel kicker for the reasons given!!!

Ans if all else fails: you could lower compression a bit by using thicker gasket(s)?

I doubt it. If your lever isn't on there properly it wonkt matter what your compression is. If it's a work out stock motor with 75 pounds compression, it'll still strip.

It seems to me that if you did want to lower the compression by putting in a spacer the place to put it would be at the base of the cylinder. Then you would not have to worry that it would seal combustion pressures.

I've got 2 motors w/ kits & strong compression and I know lots of other ppl w/ tuned motors, some are highly tuned. I've never heard of anybody lowering the compression to deal with this sort of problem. So much easier to install the correct bolt and get it properly tight.

Except then you alter your port timings.

Thank you so much to everyone who replied. The bolts that I have been using are definitely the incorrect ones. I am going to run to the local indie vespa place after work today and pick up the correct bolt so I can give this another go this weekend.

Again, thank you all for your help.