'01 Elite AF16 build questions for y'all

[imightbekarl]

Hey 2 stroke wizards! I recently picked up an '01 Elite SR in really nice shape that has been built by the previous owner. I'm looking to continue building this beast of a scooter, but I'm looking for clarity/direction on the build going forward.



Here are the current parts on this build:

• Polini Corsa 72cc kit
  
  Polini Variator w/6g rollers
  
  Polini 24mm PWK D Slide Carb w/ 118/42 jets
  
  Stage 6 pod filter
  
  TWH intake manifold
  
  Stage 6 clutch
  
  TWH clutch bell
  
  Arrow exhaust
  
  16x42 Gearing (9.1:1)
  
  RRGS Lowdown Forks (310mm)
  
  NCY Disc Caliper
  
  TWPO 220mm rotor
  
  NCY bearing throttle
  
  JDM Dio Taillight
  
  JDM Dio ZX Wheels
  
  Lithium battery

Running 32:1 premix with Castor 927 oil on a NGK B8HS plug & 92 octane fuel



Right now the bike runs really well. I bought it with a 110 main jet in the 24mm carb and it liked to get into some pretty high temps when cruising above 35mph or going WOT for about a minute or so I'd be seeing temps over 350, and if I tried to go over 40-45 mph for a minute or two I'd see temps between 370-385 and I'd pull over to let it cool down. Since then I've put a 118 main jet in there and it's brought down the temps enough that I can run over 40mph for a couple minutes without getting into danger-range. Keep in mind this is my first time tuning a 2-stroke.



Question #1: What are normal operating temps for a 72cc AF16? Will a bigger carb keep temps down? I see most of the builds coming out of Hawaii are running a 28mm carb where I'm running a 24mm. For now I've just toyed around with the main jets from 110-118 and the 118 is still pretty hot after WOT or cruising above 35-40mph but the bike seems to still be happy.



Question #2: Is the TWH intake manifold too big for the 24mm carb? Could that have an affect on the high temps I'm seeing?



Question #3: What's next? I'm looking at a Dio ZX transmission swap to run the larger pulley on the rear and get a little bit more punch in the low-end. Other than that I see mini stroker builds around the polini corsa that look cool. What type of crank is recommended to run with the corsa?



Question #4: Liquid cooling...what's the deal? I see big-boy stroker builds running liquid cooled setups with the radiator on the front of the bike. Does anyone run liquid cooling on a corsa or mini stroker setup? Is that stupid? I'm more interested in being able to run the bike really hard for longer periods of time without overheating that I am in winning races or setting speed records, should I even be looking at this stuff?

[geoffh]

Welcome, I,m not elite ace but first question will be are all the fan shrouds fitted and in good condition?.

Geoff

[jbjhillbilly]

I’m with Geoff - are your shrouds on, and in good shape?

Have you tried larger main jets, like 135? You can go to the 28mm carb with ~125 main.

You should really be able to stay at/under 350*, and be getting into the 50mph+ range.

I’d start checking for air leaks after that.

[mention]hippo008 [/mention] and [mention]oldgeek [/mention]are Honda 2t guys.

[aeroxbud]

Welcome to the forum.
I wouldn't be running Castor on a bike unless I want to regularly be rebuilding it.

[repherence2]

to answer Question #1.

we run the 28 OKO's here because all the OKO's cost the same, 24mm-28mm, fairly cheap for a go-fast carb compared to stuff like polini, keihin, and dellorto. the 28's are used because of the WOT blasting that a lot of moped riders do. check out the "oahu moped cruise" vids on U-tube, at some point, a whole bunch of mopeds will be blasting down a highway at WOT. the 28's are good for these WOT blasts, it is capable of providing sufficient air and fueling, with enough fueling to keep it cool. the 28 will pull harder on the top end as opposed to the 24. however, the 28's are not so good in the low to mid throttle range. the 24 will give better performance in the low/mid throttle range because it probably has better air velocity at that position. low end on the 28 is not so crisp but it can be compensated for.


question #3.

Dio ZX trans. if i recall correctly, you are going to need the rear pulley, drive boss, and belt fro the ZX swap.

Crank to use. the most common recommendation is either the stock Honda crank or the Malossi full circle crank. as far as mini strokers, research will tell you that the common failure point on the mini stroker is the crank. is it really worth effort, risk, and time to build a mini stroker to gain a few more cc's of displacement?


question #4.

water cooled. a lot of big strokers go water cooled because one of the biggest issues with the big stroker is the fitment of the air shroud. the stock air shroud practically will not fit and it will cause the engine to overheat. but if you go big stroker, you will probably have to carry extra drive belts with you, for some reason they snap belts.

[Lucass2T]

Jun 25, 2022 3:05:25 GMT -5 aeroxbud said:

Welcome to the forum.
I wouldn't be running Castor on a bike unless I want to regularly be rebuilding it.

Good point indeed, was thinking exactly the same. Castor oil gunks up everything, it's just plain garbage for street riding.

[repherence2]

Jun 21, 2022 14:18:58 GMT -5 imightbekarl said:

Running 32:1 premix with Castor 927 oil on a NGK B8HS plug & 92 octane fuel



Right now the bike runs really well. I bought it with a 110 main jet in the 24mm carb and it liked to get into some pretty high temps when cruising above 35mph or going WOT for about a minute or so I'd be seeing temps over 350, and if I tried to go over 40-45 mph for a minute or two I'd see temps between 370-385 and I'd pull over to let it cool down. Since then I've put a 118 main jet in there and it's brought down the temps enough that I can run over 40mph for a couple minutes without getting into danger-range. Keep in mind this is my first time tuning a 2-stroke.

i went and read you post again.  so you have a Corsa in it?   from my research on the Honda's with Corsa's, those bore kits seem to be pretty tough, it is the venerable "bombproof Corsa".   in my readings, people have taken those bores above 400 degrees.  one post mentioned that the Corsa piston has a high silica content which prevents it from expanding from the heat.  i have read of people running them at 450 with no ill effects.

in regards to castor, i just saw a video on castor oil and it's benefits.  however, the video stressed Heat having an importance in the way castor works.  there are guys like Bakaracer, 808bmw, and Tru72 from another forum that run castor on their race bikes, but other oils on their street bikes.  so, from what i gather, castor is good but it needs Heat.  in your case, it very well might be more beneficial for you to run the higher temperatures.  the way i see it, Run 'Um Hard and run it WOT to see what the max temperature it gets up to.  you already run 32:1 so you know for sure that it is lubricated.  i mean, you going know when the thing going soft seize, temps will be up but you start feeling it start to drag and lose power as the bore and piston start to tighten up. if i had a Corsa, i would put it to the test and tune it lean to run at 425 degrees WOT on castor oil.  i have read so much great things about the Corsa.  i know that a Corsa replacement piston costs more than a Contessa replacement piston, which leads me to think that what i read about a higher silica content for higher temperature capacity is the cost difference between the two replacement pistons. 

you just need to understand that 350 is just a Safe Zone.  if you tune to 350 WOT, it is purely a Reliability thing.  i tune to 350+ WOT because i never know how long i am going to ride for when i go cruisin' but if it come across some guys that want to race along the journey, i can hold WOT all day long and still be Safe.  i definitely could tune hotter and go leaner, but you start to lose that safety margin.  i read a post of someone taking a nickasil bore up to 550 on deceleration without seizing.  

[imightbekarl]

Jun 27, 2022 23:31:01 GMT -5 repherence2 said:

Hey all, thanks for the replies.

As far as the engine goes, it does have the shrouds in place and intact. As far as the Castor oil goes, that's what the previous owner was running in there so I wasn't thinking I'd want to run out and make the switch to something else, but this is the 2nd time I've heard I should switch oil. What kind of oil do you recommend?

I've also got an NCY exhaust in the mail because my arrow pipe decided to self-destruct on Sunday. I've rigged up a fix with a hose clamp to keep the silencer attached to the pipe, but I'm also interested in trying out another pipe. I've heard that the Arrow pipe tends to make these engines run hot, so I'll be fiddling around with jets and exhaust systems until I'm happy with how it's running and staying cool. 

[808ministroke]

I would definitely try a larger jet those hondas like a lot of fuel so I would throw in a bigger main jet and yet it will definitely help you out and it's probably needed

[repherence2]

what color springs are you running on the Stage 6 clutch?