ESE's works engine tuner

[ceci]

I have a fuel injected 2 stroke scooter. 2001 Aprilia SR50 Ditech. I bought it not running. Was at 2 shops that couldn't figure out how to fix it before I bought it. It sat for 2 years in my possession before I decided to look at it last weekend. Got it running in an hour.

Runs pretty good until the fuel pressure regulator starts acting funny. I'm pretty sure this was the original culprit of problem for previous owner. Regulator isn't available for separate purchase.

I'm installing an external adjustable regulator and then doing some mods, and having a little fun with trying performance mods

I guess if you can't find it it's because it's no longer being marketed

https://www.canplastics.com/features...fuel-air-rail/

[Condyn]

Posting here due to lack of general activity on the EngMod thread. What is the best way to accurately measure the crankcase compression ratio for the program? At first I thought it was straight forward, but now I am questioning my sanity. My thought was to first stick my burette into each transfer window at BDC (large bore perk) to make sure they were actually full (or as close to full as possible without spilling over the piston) then bring the piston to TDC and fill the rest of the way through the hole I drilled in the piston. Already I created an air pocket in the pin and the roofs of the transfer ducts. I know the Fluid level will equalize itself to an extent, but I cannot see a logical way to get the air all out.

And finally I have a wretched piston port, so how am I to seal the inlet port, and where is the proper place to seal it for this measurement?

[wobbly]

CCR is easy - drill a small hole in a piston , sit it at TDC and fill to the top. This number is an option in the EngMod CCR input and of course includes the transfer volume.
Seal the inlet port using plastercine - oil the piston with it covering the port , push the plastercine into place using the skirt as a former.
Then run the piston up to TDC.
You can seal Aux ports the same way if they are exposed at TDC ( they shouldnt ).

[Condyn]

Thanks for the advice. I will try plastercine. I have a matching piston with a hole drilled in it. I am concerned about having air pockets in the ducts.

[andreas]

If the ports arn't cleared under the piston at tdc- just make sure they are.

[wobbly]

You can easily drill holes in the piston skirt to eleiminate pockets of air trapped in the ducts.

[ken seeber]

Yes a separate thread might be good. But are the best ideas going to be published? Just to get used by industry with no recognition as to where the concept came from. I was / am all for publishing everything but if its any good it will get pinched. We will all need to understand this up front, and that 'industry' will try to patent it for themselves, so we will have to keep a good eye on provisional patents. Rats run 'industry'.
You can actually provisionally patent stuff relatively easily and cheaply, but you will only have 12 months after that, full patent, or let it go. And the buggers (rats) know this.

Edit, you can get up to eighteen months protection but that will cost a little extra.

Totally agree with creating a dedicated thread. Something simple like: "A clean 2 stroke". Probably under Buckets, though Oddball is another option.

[Flettner]

Twin rotary valves.
Ive changed my mind on the induction, these cases are now out dated.

[F5 Dave]

Unlike the tablecloth, which in Kermit green, I think everyone will agree is a classic.

[Frits Overmars]

This could become be a high and mighty engine Neil. Are you contemplating a chin-rest on the upper crankcase?

[jfn2]

My question is about the shape of the transfer runners. My question is do I trim some of the bottom off or is it better to leave it alone? The red lines show where I would taper the runner. Should I make it more of a 2 1/2 finger teacup handle rather than a 4 finger "D" handle?

[katinas]

Hi, with this Kx 65 cylinder is good opportunity to round the cylinder wall inner edge (green) only and leave the entrance to trans edge as it is, before the first test.

[jfn2]

Katinas:
Yes, thank you for reminding me of that. I have to run the bike in stock form first, which I plan to do the first of next week on the dyno. I will post all results.

[katinas]

Katinas:
Yes, thank you for reminding me of that. I have to run the bike in stock form first, which I plan to do the first of next week on the dyno. I will post all results.

It would be really interesting.
Other thing to worth to try, milled spark plug, that Frits and Jan advice to try, is very helpful.
With this year Huqvarna TC 85 we ended at 31,53 hp with std spark plug.
Then milled plug 31,1 hp
Then retard ignition with woodruff key (approx 3mm retard at lobe) 32.06 hp 11876 rpm (from rear wheel with triangular 16 inch woody 1992 GP Dunlop front slick tire)
Std plug with retarded ignition 31.45 hp and lower everywhere except at over 12500rpm.
Looks like milled plug shortens the burning time, maybe due to the plug inserted deeper into the chamber, closer to piston and/or due to the more open ceramics.

[Flettner]

This could become be a high and mighty engine Neil. Are you contemplating a chin-rest on the upper crankcase?

Yes it is tall, but who cares for the moment, test. It fits in the 2010 YZF frame I have.

If I find the layout works I can build a new version with the cylinder laying down / inclined to fit a motorcycle better.

My other passion, autogyros, this type of engine is ideal, wide not a problem, short front to back ideal. The central crank joining gears come in handy for prop reduction, like Junkers. I also have a surprise there.