Flash 5 Rises Like a Phoenix from the Ashes of F3

[Wheelman-111]

Greetings:

Sad scooter saga of Flash 3.26's untimely demise are chonicled elsewhere.
Since I had a whole evening, might as well pull the engine and check compression. Like 10 PSI. Ugh.

Well, that took like 40 minutes, now what? Started pulling stuff off and found the piston, e-clip, yadda-yadda.

Pulled all the rest of the stuff. Nifty tools like flywheel and bearing pullers sure make this quicker. Now with a bare case:

FRIPSplit[1].jpg (126.5 KiB) Viewed 8831 times

... Might as well split it. I'm not liking how the pump plug has been leaking for who knows how long? Something to avoid with the new build.

Well, still not bedtime yet, so might as well port the intake, something 71-MPH Flash 3.26 never had done. I did one side for comparison:

F5IntakePortIn.jpg (148.12 KiB) Viewed 8831 times

There's an ugly sharp lip on the floor of the port on the left that I cleaned up, along with some casting ridges and flashing on the side wall.

F5IntakePortOut[1].jpg (143.39 KiB) Viewed 8831 times

This shows the port height raised as well as removal of a square corner withOUT removing too much of the structure, which is needed to support the intake/carb weight.

Once all the porting is done, I'll clean the cases and start deciding: New Corsa piston and call it good, or go whole-hog with Eye-Talian or Asian crank and cylinder gimcrackery?

[kingkamehameha]

The intake tracts look sexy smooth what bit did you use?

[LMH]

You dont want smooth, you want it to break up the oil and fuel.

[swimmingfree]

Wheelman-111
good read nice photo hope to see how Flash 5 works out ..
swimmingfree

[Downsouthdio]

You want smooth after the ports.. Correct?

[LMH]

Its a mixed debate I think, the edge near the crank and the area around the oiling hole I made smooth to promote the oil flow down, all the air passage ways on the block and cylinder I left rough to help toss around the fuel mixtures, then mirror finished the exhaust port. Seems to work well all the way to 13,480 rpms.

[Wheelman-111]

Greetings:

Thanks for the compliments, Dawgs.
I was using a little triangle stone on the Dremel for the rough work. Some of those little nooks are hard to reach, and this isn't a perfect job by any means - even with a lot more work done since the "Pics" were taken. The Satiny-Smooth Intake texture comes from Poor Wheel-Photography, mostly, but also with a little steel-wire wheel shaped like this:
--[E
(The E represents the wires. Imagine a few dozen more...)

I too plan to mirror-polish the exhaust and perhaps the piston crown, but leaving the intake a little more Velvet-y. There's at least as much Folklore to this as there is Science.

[LMH]

It wraps around to the 1 but running a little rich today, its cold and rainy.

[Wheelman-111]

Greetings:

The Diamond file points the way...

Finished cleaning up a little. Cases await a decision on hardware. Hello, RedEft?

Since I don't get bare cases very often, I thought I'd post some things to consider doing to the cases in the event you want to upgrade something later. A lot of this stuff is just a PITA to do on a mounted engine; Wheelman don't like to crouch. Some of it just flat can't be done, or the shrapnel will get into the engine's Delicate Areas. So with cases fully stripped, Here goes:

One issue with the AF16 is mounting tires bigger than 90/90. 3.50 is the limit, but even that needs to be deflated to mount, and at speeds above 50 it stretches enough to rub on the exhaust mounting lugs. Shaving the case helps, but really 90/90 is probably the right call. If you insist, this is what it needs:

F5CCaseTireCutAway.jpg (179.82 KiB) Viewed 8725 times

The ZX Transmission is a worthwhile upgrade, especially for taller gears. However the wider belt needs more room between the front pulleys. That longer pulley boss causes the "Castle" on the outer Drive Face to come in contact with the Kickstarter Spindle unless the cover is shimmed out a couple of mm. I'd been using a doubled-up gasket, but repeated disassembly caused it to crumble and it's a PITA to use. I decided to mount some "permanent" washers to the mounting bolts and give up the gasket altogether. This is NOT a good idea if you do a lot of your riding in the rain, but worthwhile to me. The crack behind the cover might help the belt stay a little cooler too:

F5CoverShim.jpg (181.6 KiB) Viewed 8725 times

The washers are cemented with HondaBond for now. If it doesn't work out, it's easily removed. If it does, I plan to JBWeld them on and ease Vario changes considerably.
Another issue with the ZX Transmission is pulley clearance. This case of mine was done a long time ago, illustrated:

F5CCaseLeftIn.jpg (186.9 KiB) Viewed 8725 times

Yeah the bottom rear looks like it was chewed by WoodChucks, crude but effective. The other places don't show up so well, but see where the case edges are close to the bolt holes - that's the risk in doing this - leave enough material to be able to bolt your covers on.
Also in this "Pic" note where the starter housing needs to be cut away to make room for the Giant RedEft Malossi-for-Ruckus 97mm variator.

An-a-how, just some ideas for Mod-Men if a bare case finds it way into your Boudoir.

[Wheelman-111]

Greetings:

OK so the tire and ZX case mods are out of the way.
This next section reviews prepping the Intake port and a few other areas for Massive Inhalation.
I've already posted early rough-in for the case intake. Here's how it came out.

F5IntakePortFinalIn.jpg (110.38 KiB) Viewed 8717 times

I advise caution on what you remove in this area for a couple of reasons. One is that the case port is a weak spot on the case anyway. The Intake manifold holds the weight of a carb and airbox, and the whole assembly's "supension" is just that rear tire bouncing over the potholes, bumps and Ravines on the Bad Streets of Deepinnaharta. DO NOT, under any circumstances remove the "splitter" between the port windows. The hot cases can bend just enough there to inhale some extra air and muck up the mixture. (Or so Legend holds...) Also, see that dimple at the bottom of the ramp. That conducts the little puddle of Oil (Pronounced "Awl" in these-here parts...) to your Main Bearing. Honda-san took pains to shape this section to ensure adequate supply. Don't mess with his work rat thar.
Basically I took the whole corner off the Upstream side and raised up the "ceiling" a few millimeters. As long as it's bigger than the reed area - reeds Open - that won't be a strangle-point. Velvet-polished the walls. I don't buy "Turbulence" here as a good thing. The whole d*** intake makes more twists and turns than the plot of a bad Whodunit novel. At least the wall flow should stay Laminar if possible. Just remove and straighten where possible, and especially get rid of casting ridges that would be too Labor-Intensive for Honda to do.

F5CCaseIntake&BoostPolish.jpg (155.31 KiB) Viewed 8717 times

The file points to the right Transfer Port, which also got the Velvet Touch. Since I don't yet have my new, Top Secret top end from RedEft, I can't mark and cut the boost port. This is what Honda-san gives us on the AF16:

F5BoostStock.jpg (178.08 KiB) Viewed 8715 times

Once I get the Cylinder kit, I'll get busy matching to the gasket. After that, cleanin' up filings, poundin' bearings and pullin' (also Top-Secret) Cranks. Here's Yvette MiMew giving her seal of approval to the porting job.

F5Cat.jpg (153.2 KiB) Viewed 8703 times

[kingkamehameha]

Looks great wheelman! No knife edge on the middle support?
Dont forget to take away this lip on the transfer

[Wheelman-111]

Greetings:

Thanks for the compliments, King. I'll have a look at that transfer port lip. What risk/benefit removing it?

[paulpauly7]

better flow its matching it to the other side which doesnt have the lip.So theres a even flow thru the two transfer ports into the cylinder

[kingkamehameha]

better flow its matching it to the other side which doesnt have the lip.So theres a even flow thru the two transfer ports into the cylinder

[kingkamehameha]

Be sure to use a straight edge against the port walls to make sure they have no dips or high spots