How To Guide HT Engine Specifications



HeadSmess

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May 17, 2010
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right, today has been a success :)

1mm stainless and some swearing, and would you laugh if i said a star stake and at one point, a tractor implement? well, how else do i bend the **** stuff?

just got back from testing my 8000rpm tuned pipe i made, or 60km/h approx.(from the applet, using 750K exhaust btw)

had to resolder and drill the jet back to 0.6, and did it hit 60?

you bet your *** it did :)

awesome band from about 25km all the way to 60, 55 up hill. sounding sweet.

also very loud, until i do the final bend... yes, thats no muffler right under my ear... :LOL:

im also about to learn how to post pics here so forgive me if they dont work at first...
 

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AussieSteve

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Oct 28, 2009
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That's pretty good. My (66cc) tops out at 7400rpm, (expansion chamber not yet fitted), let alone tuning for those revs as usable. I have an SBP pipe to fit, just need to get motivated.

0.6mm is surprising for a main jet. Mine tuned well with an 0.72mm, from an 0.79mm stock.

The pipe's looking good.
 

HeadSmess

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mines the Z48, and i had the jet at 65...it just didnt wind up when i piped it. so 60 it is :)

um....with the standard exhaust, with a 13mm outlet over the stock 10... i got 66km :) no tacho, so i guess 8500...

but, THIS holds the speed, unlike the stock, which as we know, dont like much over 40 on the flat...

the next experiments with pipes? hydroforming, using just seam welded sheet, profile cut to shape... make em thin...light! ring..ting...ting..ting...ting

that pipes just a very temporary setup like that...though it is sorta cool... :D

earplugs!
 

AussieSteve

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My bike got 52kph on the flat standard, after some basic tuning and drilling some holes in the exhaust. With the shift kit, I can get about 70kph max on the flat and about 80kph on a gradual downhill. I only weigh 50kg, though.

If you accurately calibrate your speedo by sitting on the bike and rolling forward one turn, then entering that value / pi as the diameter, you can calculate rpm from your speed using JPilots Gear Ratio Calculator.

The primary ratio is 20:82, (4.1:1) and the secondary ratio is 10:44, (4.4:1), for a 44 tooth rear sprocket. (Adjust to suit your rear sprocket.) Leave the third field at 1:1.

You'd find that any further refinements of the pipe would result in minimal gain. You'd get a much better improvement with some balancing and a high-compression head at this stage, along with a decent carby. Not CNS etc, but Mikuni or similar quality.
I have a Rock Solid Engines billet head, but at 16:1 CR compared to the stock 6:1 it makes the engine very hard to turn over.
 

HeadSmess

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May 17, 2010
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yeah, i could be anywhere between 35 to 55 on the flat before i did any tweaking, but most of the time in the lower regions.... only another 16 kg here :)

temperemental? yes. right time of day when the humidity is just right, she would scream, then a few hours later? hmmph. the sort of times you wish you had spent some time setting up the derailleur properly... cant do much in granny gear.

interesting that with the now much leaner settings, its less grumpy, and in fact, sorta prefers the heat... i shall see as the days get longer i suppose, if it stays that way...

80 on a pushie.... nah, ill wait til i get my license back to do 80+ again :)


one last thing while i think of it.

indexing spark plugs. ideally, the open side of the gap should face the exhaust port. i have no idea why, but its one of those things that can make a marginal difference, and is far more noticeable as the cylinder size increases. i noticed my head was on 180 degrees out.

shame i always have to make three or four tweaks at a time so i can never really point at one thing alone.
 
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steinway

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Apr 30, 2010
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a little bird told me that the generator on the 66cc engine can output electrical power to lights which upto 5-9V 4.8-18A (AC).

Is there anyone had use this source to your lights?
 

HeadSmess

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May 17, 2010
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and that lil bird shoulda mentioned search too :p try the electrical section, perhaps....

(ps...i severely doubt it can give 18 amps!)
 

Ivan H

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Mar 29, 2012
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22
Hi Steve, heres some info for anyone who ever wants to split the cases or replace the main or countershaft bearings. Case bolt torque setting 75inch/pound, crank end float 0.003" to 0.008". Recomended to change all the case fasteners for automotive grade or high tensile socket head. Cheers
 
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