Kimjon

Normally the valve cover vents into the air filter and any dirty oily blow by is fed directly back into the motor and burnt in there.

I removed the stock airbox, so had to come up with a solution.

Option A: do nothing, vent to atmosphere. But end up with oil everywhere.

Option B: run a line, dump to ground like an early motorbike would. Fine on the road, not so cool on your own nice concrete driveway.

Option C: run a catch can like a race car would.

So in true style I elected for the most complicated solution (Option C). And rather than spending around $70 to buy one, i further complicated it by making my own scaled down version on the lathe.

Bracket:

Mounted loosely in position:

It's loosely bolted there for now, and missing the sight tube (4mm clear pneumatic tube, will allow visual of oil level in the catch can)...but looks the part.

The throttle linkages are a mess on these. They are reliant on the governor and when that's removed they flop about.

I got it functional, but it looked untidy. So I cut it up and reshaped it:

Before (functional...but pugly)

And after (still ugly, but better)

I'll paint it and see if it "disappears". If not and it still annoys me, I'll mill one up out of alloy.

With some of the mods I'm doing, more air will be entering the motor. I geeked out and read up as much internet information as I could find on the topic.

Solution, drill the main jet out from a factory 0.72mm up to 0.94mm. Actually 0.90mm was the recommended...but I didn't have a drill bit that size, so 0.94mm it is.

I guess if it runs super rich, I'll look at swapping out the carb for a mikuni or similar. But I'll cross that bridge if I need to later on.

And dry fitted to test...happy for now, will port match after welding on header pipe.

And exhaust flange (hehe...flange )

Got a bit more done after work yesterday.

Motor mount:

Started tearing down the motor. I'm waiting on eBay parts...probably won't see them until after Christmas? But may as well get started now anyway.

Clutch dry fitting on motor to figure out engine mounting

Rear sprocket

24 minutes ago, 63Ragtop said:

Front end off your other machine of mayhem? 

Upcycling at its best

Kind of forgot about this project. 

Started on making a motor. Using a Honda clone, I'll do the usual modifications to make it faster...plus add my own flavour to it as well.

Engine mounts, clutch, chain and sprockets...plus the exhaust up next. But all in good time...

Doing a fantastic job. 

Keen!

What's "the rules" in regards to running two bikes, one for dirt...one for the drome?

I think Lucas must have won as his was the fastest and broke down fewer times.

But no "official race", just a few of us goofing around. To be honest, that was perfect for me as I'm not an overly competitive person. Maybe next time though as the velodrome rocks!

It was a fun day, low turn out due to rain...but that cleared up and we got a few laps in.

My bike has tuning issues and is not running at peak performance, but it would wind up to 65kph. I'm thinking a bigger carburetor is needed, so I'll keep an eye out for one and try it. But still happy as with how fun it was to make something and ride it.

Thanks to the others who helped out, great to meet you all.

I'm here now...bit wet. But still keen?

Awesome!

It's cool, push it into a corner and call it art

Motor does just under 9000rpm...cheap Chinese rev counter was wrong. I put reflective tape on flywheel and clocked it with a laser. Slightly relieved, as the numbers just weren't adding up before.

I was watching that on trademe...was very tempted, but then thought better not.

Glad it's gone to a good home.

And Sunday at the drome?

Sunday would be awesome.

Whatever it takes I guess? Your call

9 hours ago, peteretep said:

awesome man, whats the speed like? From memory, when I had it as a 2 speed setup, I got it up to around 65-70kph

 

how is the engine running with the new carb? It should rev to about 9000rpm. When I first had it, it would get up there, but as things broke it started to have a break down in ignition

Hi Pete

Glad you like it, as I felt bad cutting it up to begin with, but I had a vision (and an angle grinder plus welder ).

I've had it up to 70kph, but it hits the wall about there and won't go any faster.

The carb is running super rich, and I'm going to have to double check revs, but my tacho says I'm only getting 3500 under load (its possible im on wrong setting, but don't think so???, well that's if the Chinese to English translation is correct in the manual???).

My gearing is much taller than yours was, so I think it's a combination of high gears and bad tuning...but fuck it, going to run it like that and worry about fixing issues another day.

Cheers

Kim

That's awesome! I have an old parts washer with no pump...may have to copy (blatantly steal) your ideas.