250-500cc R&D HUSKY 360 HEAD

the is was my thought too on the stall factor riding single track
it is my hope to dial it in fairly easy with a piece to copy
if it is affordably feasible I will share the info or people that are doing mine so others can get in on it
thanks to everyone here and especially to Colemanapp for the help

keep us posted 2premo, im contemplating redoing mine to auto decomp rather than chainsaw mod, reluctant to mash up my spare head tho.

I am also interested in the decomp head. I have a local fabricator friend who would be able to do the work for me. Please post photos and descriptions as to what needs to be done.

I'm planning on tearing mine down again soon. I'm going to ask a friend with access to a 3d scanner to scan the head and i'll make the files available.

Coleman/2premo, did you guys ever end up collaborating on this?

Also, did anyone find a US source for the vacuum-actuated compression releases?

On the manual decomps, do you have to hold those down while you kick, or does it automatically disengage after the engine fires up?

I'm very interested in doing this on my bike, especially since I have access to all the machine tools I would need to make it work. I could do the manual decomp, that would be nice for hare scramble starts or after killing it on a tough hill; however, the anti-stall of the auto-decomp (and no buttom) is really appealing...

If anyone has found a US source for those auto decomp assemblies, I may take a crack at this.

Edit: Now that I think about it, I don't quite get how the auto decomp works. If it decomps when there is no vacuum in the manifold, wouldn't it also open at WOT?

A manual decomp is truly manual, pull the lever and it's open, let it go and it closes. The engine won't start while it's open so it's only really helpful for kicking it through when the engine is flooded or trying to find tdc.

I don't think you can get the Victa vacuum decompression valves anywhere over here. I'm sure you could get them from down under but shipping would probably be killer.

Coleman sent me the head, a machinist is looking at making the bung also what it would take to produce a quantity, another guy will bore and weld the head and a third will re-curve the combustion chamber, it will not be soon but have answers for a conversion that can be duplicated or sent to the same people
the decompressor was only available "down unda" I bought two and saved on the shipping, if someone would be willing to play bank others could have a group rate and save by volume and combined shipping
the reason for going auto is the bump start advantage, I have stalled on single tracks and when I do am VERY unpopular
having access to all the machine tools can sometimes be a hindrance, watching a great machinist humbles me and as such want that grade of product when riding in areas where the only recovery tool is a rotary wing aircraft (helicopter)
on the WOT vacuum issue it seems light to close and the valve seems to want to seat itself under pressure, also even though the vacuum signal is weak it seems to be adequate or a design would have been done when the original head was concieved

I think it opens slowly so if there is a momentary loss of vacuum it stays closed.

My original setup had the vacuum line going to the carb which had been tapped with a barb. I've since put a plastic barb on the manifold to ease carb removal and swapping.

My bike was a bear to start when it was warm when I first got it. I spent a long time swapping parts (stator, flywheel, cdi, coil, plug wire, plug) with no change. Finally moved the kicker up a couple of splines and viola! It's cured.

The kicker had gotten sloppy and the extra play wasn't allowing a good enough kick to get spark. In my experience you've got to get a good enough kick to get about 3 turns of the engine to get it going.

it does need to spin and there is the problem, the kicker itself is in an odd position
when mine was giving me hot start issues and I could roll down hill just being above it on the pegs I could kick it once or twice and I would start fairly easy every time

Another good thing about that head is the fact that the 360 has been known to break cases upon kicking. I know of several examples of that happening. You'd definitely be putting less pressure on those cases with the decomp installed.
Watch your routing on that decomp hose to the manifold or carb. I ended up burning a hole in the hose and then the victa rattled apart and ruined my piston and barrel.

does anyone have the original instructions?
it was a few pages, pictures and a good description of the work to be done
I saw a pdf at least I think it was pdf last year and can't find it now

I used to have the original instructions but cant find them. They show that you route that vacuum line from the victa fitting and tap into the carb using a barbed fitting. I have mine routed to the intake boot as uranys noted. Really nothing else to it other than the head, the victa fitting and a vacuum line.

I was hoping to find them online again but lost the link when my computer died

This was the link but it's broken:

http://www.firstclassmotorcycles.com.au/downloads/SPEDOC1.doc.pdf

Maybe they would send a copy if you email them?

is that the outfit that had them made

Web Archive :

http://web.archive.org/web/20130409...smotorcycles.com.au/downloads/SPEDOC1.doc.pdf

thank you
that's exactly what I was looking for