Wasp Ped Buildarewski Bitches!

[qwerty]

Not chrome nor polished.
Just machined aluminum.

Thansk for clarifying.
I oversimplified due to prejeduce on too bright colored casings, it requires care to prevent scratches, plenty of cleaning and ideally a chromed engine shroud to look good and as you need to buy used ( no new ones made any more) it will certainly ave smudges despite a still 3 digit pricetag which would bugger me.

[Basement Cat]

Did some testing with Wasp Ped again today.

I drilled and tapped a new head today for a comp release and put the Alro racing cover on. For now, the timing is at 0 degrees.

I cut out the transfer divider at the bottom to see if it makes a difference. For now I am leaning towards not really. It does feel like there is more power in the mid range, and it does seem like it's easier to get it revving, but the numbers speak otherwise.

Top speed is about the same as before (41-43 mph) so the top revs haven't changed since the last head. However, since I didn't change any of the port timings themselves, the lack of change in top speed is not surprising. At least I know that for now, the flow through the bottom of the transfers isn't really a problem.

I also lightened the piston by a small amount on the lathe and opened up the sides. I think it lost about 0.5 grams of weight which isn't much (it went from 64.33 g to 63 something g).

Free revving got it a little over 15K, which is nice, but that obviously doesn't mean much for the numbers under load.

Additionally, I took one of the foam pieces out of the airbox and wow what a difference. Usually the stock airbox isn't very restricting but I guess the 60 has so much pumping volume that it is restrictive. The biggest engine I have used the stock airbox on is a 40 so this was my first time putting one on a 60. I think that I'll be switching it out for a UNI filter now. I did run into some fuel delivery problems though so it might just be that my carb was being wack.

Finally the softer pop off spring doesn't appear to make a difference, or at least, it is difficult to tell since I did also change the piston weight and removed the transfer divider.

My idle has been pretty weird but now I am thinking it might just be because of the airbox. When I go from top speed and let off the throttle to coast to a stop the engine shuts off. I think that it's choking for air and flooding itself which causes it to die. When I took out one of the foam pieces I noticed that I had to turn out the low needle MUCH more which lets me know that the engine was able to get more air at idle.

I'll try sorting this out and will update in the future. The cold is approaching in my neck of the woods so I'm trying to hurry before it's freezing out.

[Basement Cat]

I had a chance to do more testing.

Weather was 71 F with 45% humidity where I am at. Also the sky was partly cloudy which allowed me to get a good GPS signal.

Wheels are pocket bike type with 11" diameter tires. Gearing is 8/72.

All I can say is....

Holy shit. This thing is FAST.


The following is my take on the mods that I did.

Cutting the transfer divider:

I think that it actually does help with scavenging in the end. I tore the engine apart yesterday to look at the piston and the soot marks on the piston were noticeably different than the last piston that was run with a normal cylinder. The piston in the new engine had a sort of arrow pointing figure in it. This is a good thing because the arrow pointed the way the transfers are angled and the largest blank spot (no carbon) was near the intake transfer. So I think that cutting the transfer divider does help improve scavenging. This is supported by the fact that the mid to upper range power is much better and the engine was consistently revving high under load (max of 12240 RPMs). Top speed is in the 43-45 mph range consistently as determined via GPS. This thing has absolutely no problem revving above 11500 RPMs under load, even going up an incline. This was verified by my tachometer.

I think that cutting the divider works because it might help correct for the fact that the engine spins in the opposite direction with the skopod kit. The way the skopod kit sets it up the mixture from the cases hits the exhaust transfers first instead of the intake transfers which is the complete opposite of what Zenoah wanted to happen in this engine given the transfer port layout. Cutting the divider helps to get more mixture into the intake transfers which are usually the ones primarily responsible for moving stuff from the cases to the combustion chamber.

I have to add the caveat that there is also one more mod that was done to the engine. I lightened the piston and opened up the sides a small amount. As a result I can’t fully credit cutting the divider for the observed improvements, but all a lightened piston should do is let the engine rev up faster. Also the amount of weight I cut out is small enough that it might not even make a difference (only about 0.5 grams which is only a 0.7 % weight reduction). Finally, cutting out the sides in the piston might also have improved transfer flow, especially since I cut out more on the intake side of the transfer cut-outs on the piston, but honestly I am not convinced that the small amount of work I did on the piston would lead to this drastic difference in performance.

Changing the HDA48 pop off spring for one from an HDA 223:

I think that this did actually help my idle in the end. The reason why, is that for yesterday’s tests there were a few issues. First, it was constantly drizzling so the engine was pulling in a bit of water because it was so wet out. Two, it turns out that my pulse line melted onto the cylinder which caused the carb’s pumping mechanism to behave erratically and function improperly. Finally, my tires were really low on air so it made it harder for the scoot to take off. Once all those things were corrected the carburetor works wonderfully now. The engine no longer cuts out when I decelerate rapidly from top speed and it is able to idle easily in the 3000-3300 RPM range.

Overall I am more convinced at this point that these mods did, in fact, improve the overall engine performance. At the very least, it definitely did not make things worse.
If anyone is interested in cutting the transfer divider out, be careful because if you go too far you will cut a hole through the cylinder. I would recommend cutting most of it off but leaving a small nub to avoid cutting through the cylinder.

I will be popping the cylinder off in the coming weeks so I will post pics then. In the meantime though, I am going to have fun mashing the shit out of this thing, hahah

Finally I want to keep in mind that so far I have made no changes to neither the intake, exhaust nor transfer port time-areas. I am hitting these numbers with what is essentially a very lightly modified stock cylinder. Personally I am pretty happy with these results since this engine has port timings that are aimed at making alot of low RPM power and the power peak is supposed to be in the 9k range.

[MrTea]

Have you been able to measure the pop off pressure..
... J.

[Basement Cat]

Have you been able to measure the pop off pressure..
... J.

I do not have a gauge so I have not been able to measure it, sorry. The HDA223 spring does feel softer though, but that's all I can about it.

[Basement Cat]

More pics! I switched out the lower clamp for a black one and put my Alro racing cover on:


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[MrTea]

I do not have a gauge so I have not been able to measure it, sorry. The HDA223 spring does feel softer though, but that's all I can about it.

Find a bike pump with a Schrader valve fitting and a pressure gauge.
Or a car tyre pump...
The fitting needs to be the type with a rubber doughnut inside, that is compressed when you turn a lever.
Get a piece of fuel pipe and squish it in to the fitting, and lock it on...
OR... get an old automotive tyre valve and put in to your fitting and push the fuel pipe in to it..
Basically.... Bodge it all together.

Stick the fuel pipe on the metering valve and pump...
Due to the differences between pumps, pay no attention to others results..
Use your own readings for your own circumstances..

Do the HDA type carbs have a pip sticking out, that you can push the pipe on to....
(I know, I will look for myself)....
... J.
PS... I love them covers.

[MrTea]

To test the pop off on the HDA..

Remove the cover with the 4 screws..
Put the pressure pipe straight on to the fuel inlet pipe...
And pump.
You can click at the metering lever to settle the pressure.
.... J.

[Basement Cat]

To test the pop off on the HDA..

Remove the cover with the 4 screws..
Put the pressure pipe straight on to the fuel inlet pipe...
And pump.
You can click at the metering lever to settle the pressure.
.... J.

I was able to measure the pop off with your suggestion. I hooked up a mountain bike shock pump to a piece of fuel line and plugged that into the fuel inlet barb. Pump, pump, pump, hissssss. I did it a few times for the different springs to make sure my numbers were a representative average. Here is what I found:

HDA 48 with stock spring: 40 PSI
HDA 48 with the spring from an HDA 223: 30 PSI

So the pop off is 10 PSI lower now. I think that this has helped my idling issue since now the engine runs really well. It no longer cuts off when going from WOT to idle under rapid deceleration. Believe me I tried to get it to cut out, but it kept turning. Tuning the carburetor is easier now as well, although I think that some of the help has come from removing some of the foam from my filter element.

I must note that I didn't switch out springs for the same carb since I am lazy. I had two separate carbs (both HDA 48 models for the 60) and each had a different spring. Still, I think this is a valid comparison.

[Basement Cat]

I also measured the pop off pressure of the 77B carburetor that I will be using. The carb is brand new and has never been used. The pop off was measured at 30 PSI as well.

[Basement Cat]

I swapped the JP pipe for an ADA 60 pipe. It's 1 pound lighter. I also got some more Ti bolts and speckled those all over the ped (if it's a gold bolt then it's probably Ti). Additionally, my GP460 pullstart broke so I swapped it for an RC pullstart that I had lying around. All these changes actually shaved a good amount of weight!

Weight with the Al pole is 36.6 pounds! Once I finish the CF pole and new stem I will probably lose at least 1 more pound so this thing should be pretty light. Overall I'm happy with even the current weight since this thing is 60 powered.

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[Depths of Hell]

Much better pipe choice in my opinion.
Looks like you have been running her.

What kind of numbers do you have under load, waiting patiently.

Beg you pardon sir, but the stock air box is killing me.

Can I suggest drilling holes in the plexi-glass chain guard. It will help with clutch cooling. I'm sure it is already on your to do list though.

[Basement Cat]

I know, the stock air box is really an unattractive piece, haha

Good idea on drilling out the chain guard. I hadn't considered the effects that it would have on cooling. I'll be drilling out some holes in it in the near future. Thankfully it has been rather cool here (60-70F) so I have not had to worry about overheating.

I did get some numbers. I took it out for a short 45 minute ride and hit 13K under load which translates to about 48 mph with my gearing. I added more detail here: http://www.billetboard.com/showthrea...ne-Build/page3

Damn this thing wants to rev out now!

Overall I'm very pleased with my current results. 60s are such a great platform and I think that they get a bad rep because of how expensive they are. But I hope that my piston port build can show that you don't have to go crazy reeded to get it to GO. It's also nice that I don't need to worry about the plating shitting the bed.

[Pushinit]

Take two nail and put them through the pipe spring holes on the mani. It keeps the bolts from backing out all the way, and you can use a spring on the nails.

[Guest]

Take two nail and put them through the pipe spring holes on the mani. It keeps the bolts from backing out all the way, and you can use a spring on the nails.

u learn that from maverick?