[maciekTopic starterBerichten: 12]

I hope You all are having a good summer!

I broke the sub-frame on my bike, while the engine was out to install the re-inforced replacement I changed the seal. It did seem to help, as I downjetted from 88 to 84 and my head temps stayed around 350F/175C. I also put a notch in the slide to lean the idle to a reasonable mix and dropped the rollers down to 4.7gr. Did half the rally this way and all looked good so I went down to an 82. It runs great, peaking around 400F/205C and approaching that magic 80km/h mark at a bit over 7k RPM. Still seems kind of low, so I’m thinking to try some lighter weighs and the 100mm rear pulleys, see how high of an rpm it will pull through and still variate fully. Hopefully the 9.5:1 final gearing is not too high.

Also, maybe you guys have some input on rotary-valve intake timings for this thread: http://www.mopedarmy.com/forums/read.php?7,3509334

Peace,
~M

[maciekTopic starterBerichten: 12]

Thank You! That is exactly the kind of information I needed. Seems not many on either side of the pond run this cylinder, at least not people that bother to use a tach ;). I have to get some sleep before work, but I can’t wait to try some things tomorrow.
~M

[maciekTopic starterBerichten: 12]

Thanks, I thought 92 is very big as well, probably compensating for the exhaust leak, I found no others, and I did put the proline on without any sealant (just to see if simonini did any better job on the clamp then polini or tecno). It does run pretty well at WOT and the plug-chop looks just right, just very rich at idle.

I was originally set up for torque, 12.25:1 gears and estoril, top crank cut to malossi specs, and just the intake and mild port match done on the case, running jets in the mid 70s and topping out around 65km/h, 70 on a good day, 7-8k rpm… Then I had an unfortunate accident where the clutch blew up and put a hole in my foot (http://www.mopedarmy.com/forums/read.php?1,2715103,2718946) and broke the transmission cover around the bicycle-mode button. I took a break from this bike.

Meanwhile I decided that since I had to re-build another transmission I’d try taller gears and maybe get to 80km/h+. When I finally got the bike back together with new clutch, trans, and gears, I cracked my variator on something (still don’t know when/what, having too much fun) which bent the crank, which promptly snapped. So, over the winter I ported the cases close to the maximum, transfers and boosts all the way down to the crank lobes, and used an anticipato crank. I tried the biggest jet I had first, an 82. It four-stroked at idle (time to shave the slide), but still seemed lean at WOT, plug chop confirmed. Hitting 75km/h and only 6-7k rpm max, and the vario is not tuned in and variating fully yet. This is according to a TinyTach which I’m starting to doubt.

I figured 80s, but I got up to 98 just in case. I also finally got the proline so I installed that.

I tried the 80 first, lost power and top speed, felt lean but i did a chop anyway and it confirmed it, 90 was better and faster, but still looked lean. 98 felt rich, four stroking up most of the throttle, but would clear out at WOT. 94 was fastest so afar so I chopped and it looked a bit rich, so I went with the 92 and essentially got back to where I was with the estoril.

80s seems more reasonable with this much case work at sea-level…I’ll try some sealant and hopefully it will help.
I also tried lightening up the vario weights which got me a few more rpm and about the same top speed. I have heavier I might try, but I need to get/make some lighter ones, seems more likely it may be variating too early.

[maciekTopic starterBerichten: 12]

Interesting, I’ve never seen that, I will have to try it. I assume it does not set completely solid like metal epoxy/jb-weld, and you can remove the exhaust and re-apply fairly easily?
Thanks!
~M

[maciekTopic starterBerichten: 12]

Inlet does seal (I do have the bike put together and running already (http://vespa-ciao.nl/forums.php?m=posts&q=34469). Here is a better picture of the inlet window:

I have made one too wide before to where I could see light coming around the side of the crank lobe, so on this one I left at least 1mm overlap on each side. The previous crank broke after I hit my variator on something and rubbed against the sealing surface as well, but it still seems to seal pretty well. This was My excuse to go ‘big’ on the case porting this time around.

Gaskets seem to seal ok, I use fiber gasket and coat it in RTV. I did find a leak a the carb mounting so I filled the slot in the clamp with rtv behind the shim, and that seems to have helped.

Main air leak seems to be at the exhaust pipe clamp, I’ve had three different brands of Vespa exhausts and none of them will seal unless I use some copper RTV on the flange, and then it’ll still leak black goo. I figure that’s just how it is. How important is the exhaust seal, and what do You guys do to get a good one?

Thanks,
~M

[maciekTopic starterBerichten: 12]

Yeah, pay attention to the bore size more than the cc claim, sometimes you will see the 43mm bore as 65 or 70cc, and the 46mm bore usually as 75 or 80cc, but i’ve seen it called 70cc too. I figure ‘nozzle’ must mean ‘jet’ :), and like edjuh says, you need to know what size wrist pin you need to match the small end of the piston rod, it can be 10 or 12mm.

I know this is a nice kit too:
http://mopshop.de/shop/product_info.php?cat0=441&cat1=496&cat2=499&cat3=WVd4cw==&products_id=1422&osCsid=98159fb3c5a252ee1230f9df122dd59e

[maciekTopic starterBerichten: 12]

I would suggest keep it to a kit that is 65cc or under, or more specifically, one with a 43mm piston. most 70cc kits are 46+mm and require you to grind the mouth of the case larger to accept the cylinder sleeve. The 43mm kits will slide right in and bolt right on without any grinding on the case, though there is much to be gained from matching the transfer ports to the kit.

For your first kit I would suggest the malossi 65cc, or another 43mm that has triangular shaped transfer ports, like the stock ones, just bigger. That way you don’t have to do any grinding on the case right away and it won’t suffer as much, and if you do work on the case you only have to match the ports, and not open the mouth bigger. The Polini, DR, and others with the D shaped ports are harder to match the triangular ports on the case to, they actually cover up some of the stock port, and suffer more if you go without matching.

[maciekTopic starterBerichten: 12]

malossi has different springs for the vario and single speed clutch in their catalog, for all i know they could be the same thing painted different colors tho. try shaving the unnecesary metal bits off your clutch shoes to lighten them up first while you have it apart, and see if that is enough.

[maciekTopic starterBerichten: 12]

Thanks for the tips guys. I would prefer to wait to find a points version of the malossi case because I already have an electronic ignition that will install cleanly in that, and if I were to get the points version I would have to buy another electronic ignition, and those are rare and expensive over on this side of the water, that adapter plate sounds like it would work, i hope it’s not too big bulky and heavy. I’m hoping someone over there has a malossi points case laying around because they switched to the electronic hehe :).

Here’s some pics for you guys, this is the last pic i took of my bikes before I sold the red one:

Here is some bits of the kinetic to give you an idea of where I’m going with it:

[Gebruiker]

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