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Post by AtariGuy on May 18, 2017 0:44:52 GMT -5
After much deliberation and recent demonstrations of performance increases with the chief financial officer and house president (my wife), we have concluded it's time to consider upgrading a 4poke. Should she read this posting, i'll be in the dog house for a month for calling her scooter names though.
We finally had a chance to take both our scoots out for a cruise on mothers day, and we couldn't have asked for a better day to ride. She even had a chance to try my 2T venice. Thats when i discovered her cvt is suffering from some spring fade.
So my first order of work is new rollers, clutch springs, and contra. Cvt cover venting is also in order. Also, it's been missing its stock airbox snorkel, but i haven't had a chance to upjet the carb to accomodate it. It currently has electrical tape covering roughly half the airbox to choke it. Third, i still need to replave the fuel line (to tyvex) and add a manual shutoff. One of frankenmech's famous plastic ones. (wink)
Future plans, 47mm or 50mm. If 50mm - a naraku hd crank, airsal lightweight piston, and 24mm carb. 20mm carb for the 47mm kit. Big valve head, A9 cam, oil cooler, crankcase ventilation, and an aftermarket exhaust. Cvt and gear mods afterwards. Will post some pics in the next couple days as i can.
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Post by dan50 on May 18, 2017 1:40:43 GMT -5
To cool the CVT this idea is from a thread that I can't find.
There is a pop-out plug on the top rear side of the engine fan cover. Use a PVC piece that threads into that hole and connect a somewhat large hose (5/8" to 3/4" ID).
With a hole saw, drill a hole in the top front of the CVT cover. Install a piece (metal because of the heat) that will accommodate the hose. The fan that forces air through the engine shroud will also force air into the hose that connects the fan cover to the CVT. This will get cool forced air into the CVT. I remember the author of that thread said his CVT ran about 100 degrees cooler (and for very little money).
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Post by 90GTVert on May 27, 2017 5:03:08 GMT -5
To cool the CVT this idea is from a thread that I can't find. There is a pop-out plug on the top rear side of the engine fan cover. Use a PVC piece that threads into that hole and connect a somewhat large hose (5/8" to 3/4" ID). With a hole saw, drill a hole in the top front of the CVT cover. Install a piece (metal because of the heat) that will accommodate the hose. The fan that forces air through the engine shroud will also force air into the hose that connects the fan cover to the CVT. This will get cool forced air into the CVT. I remember the author of that thread said his CVT ran about 100 degrees cooler (and for very little money). |
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Post by AtariGuy on May 31, 2017 20:19:16 GMT -5
Did some diggin in the cvt today. Definitely room for improvement there. It has a 669-18-30 bando thats glazed and shows some slight threads, found an aramid 681-17.7-30 mitsuboshi belt on fleabay for $11.82 shipped from TN, will have to put in an order for it. Should give me more room to shift. Rollers are well used, but don't show any flat-spotting. Never realized though how tiny that vari is in these 4t's, its so purse chihuahua cuuute! Thinkin back at the ole 2t venice, that vari's a beeeast! Makes me think there ought to be a larger diameter performance vari, just not sure if my bendix will give one enough space, the case is roomy though.
Will consider 4, 6, and 8 gram sliders and a set of 1000 rpm clutch and contra springs as well. Gonna consult with the house president - eventually.
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Post by dan50 on May 31, 2017 23:55:56 GMT -5
That Mitsoboshi 681x17.7x30 is the same belt I use on my Dongfang. The stock Bando belt seemed too short, The belt at a stop was only 1/2 way up the clutch pulley. I but the 681 belt on and gained a few MPH. I have about 1,000 miles on my Mitsoboshi belt and no sign of wear. Good quality belt.
1k contra, 1k clutch springs and 5 gram rollers is the CVT setup I have. Stock variator & clutch and 11:1 gears.
For me it keeps the variator from reaching full travel until about 25mph. The engine is in it's powerband and smoothly accelerates faster. I got 42mph out of a stock 50cc engine, the same CVT setup with the 47mm BBK got me 46mph.
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Post by AtariGuy on Jun 1, 2017 13:14:46 GMT -5
I found a .7mm shim i'm using currently between the vari back plate and the boss to allow deeer first gear and slightly higher rpm loading. Its brought my 0-30mph times down considerably. Just that single shim's performance improvement gave me more confidence heading onto the busier roads here in town.
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Post by AtariGuy on Jun 13, 2017 15:58:41 GMT -5
Well this daily rider had a small scrape today. I was teaching my wife's eldest son to ride, and at about 5-10mph he locked the front up and cocked the handlebars. He fell one way, the scoot did a nose-down somersault the other direction into the grass.
He's ok. Scrapes on his palms, elbows, knees, and a bruise on his hip, but he's ok. He was wearing mechanics gloves, jeans, a zip-up hoodie (75 and humid), and a bicycle helmet since we were in a parking lot and told him not to take it too fast. We were just learning basic controls, go, stop, turns. Didn't yet get to the part about straightline only braking.
The scooter, however, took some damage. Mostly scrapes and dings on the plastics, a cracked mirror, and whatnot. We'd been missing the battery compartment cover, the battery flew loose and tore the negative terminal ring from the wire. I didn't give it a thorough look-over yet, but just a glance as i wheeled it back to the garage. I'll update this... sooner or later.
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Post by AtariGuy on Sept 8, 2017 16:51:42 GMT -5
Just some updates - ordered a 47mm cylinder & head kit. Still looking into a 47mm big valve head, found a few domed pistons to use (honda c70 type pistons.) Also digging into some information on stroker kits, possibility of raising the cylinder, and timing chain length modifications if needed - or straight building a chain in which case i need to find the size of the chain itself. Also been researching the exhaust pipe. I've come across a lot of information on exhausts lately, dug through the forums for custom/home made mufflers (a couple of brents were pretty amazing) and realized it's mostly a means to expel the exhaust gasses (unlike the 2t exhausts which need a tuned expansion chamber) so i think i'll order a black header pipe, then find a bolt on muffler - or make my own. Haven't completely thought that far ahead yet. Still digging around for more cams to test and measure. I haven't forgotten about it yet (which surprises me cuz sometimes i get so deep into stuff and information that i forget about previous projects i planned). I have found a good list of A# cams, and i may dig into some 150cc cams as well since some of them can be modified to run a 50. Either way, this scooter will be the test subject for performance and economy runs on the cams. side note again, found this info on some 150 cams - 150 cams profiling/data collection. I'll be posting more here soon. Happy scootin! |
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Post by AtariGuy on Oct 13, 2017 17:50:41 GMT -5
Elbows deep in scooty engine at the moment. Prepping for upgrades. Also installing a diy pcv vent/filter. Built very similar to 90GTVert's boost bottle diy, but stuffed with filtery crap - using a piece of a 24x24 cut it yourself airbox filter sponge at the entry, then a small bag's worth of cotton balls on top - capped with a vent and a micro k&n style filter for automotive pcv stuff. Taped it all together with about a yard of duct tape. 3hp right there. |
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Post by AtariGuy on Jul 15, 2018 17:21:57 GMT -5
I really dont report much on this scoot, but figured i'd poke in here and mention i gave the scoot a fresh 681 belt, stock torque and clutch springs, oil change, reset valve lash to 0.002"in/0.003"ex, and gave it the ol dirty onion!
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Post by AtariGuy on Jul 15, 2018 17:27:18 GMT -5
I should note that the homemade pcv can i made didnt work out, blew the mini-filter off on the first long ride (30+mile) and oil vapor still made it through it. Plenty of residue on the fender where the k&n filter blew off...
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Post by AtariGuy on Jul 16, 2018 13:35:08 GMT -5
Gave the ol bird a ride today, it seems down on its power still. Could be the 681-17.7 belt, i know stock is 669-18, but i was going on some info from previous talks with dan50 last season and his use of a mitsuboshi 681 belt. Might try opening up the valve lash to 4/4 rather than 2/3 as well. I reeeeeally need a compression tester... |
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Post by 90GTVert on Jul 17, 2018 8:41:22 GMT -5
Sometimes just changing RPM that the CVT operates at makes quite a difference. My TaoTao is slower than it used to be and all engine checks are good. AFAICT it just won't hold RPM quite the same (I've had to replace CVT parts). If that belt is causing any changes to the RPM at any point it could be an issue. I've never tried the 681 belt, but I have tried an OR belt on a non-OR CVT in a 2T. The longer belt had slack at rest and it would be sluggish getting moving till it took up that slack. Could cause problems on the high end too or maybe just alter RPM overall or in spots.
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Post by AtariGuy on Aug 13, 2018 17:05:02 GMT -5
Update - My parts came in from aliexpress on saturday. I neglected to mention (for a surprise) that there was a 50mm bore and head (standard diameter 69mm valves) and a9 cam with the assorted jets and blue springs set - all from "official glixal store". First off, quality reports on the parts. They packaged them in lightweight cardboard mini-boxes and well sealed plastic bags. Nothing was damaged in shipping as far as i could tell. A couple casting flaws and one machining flaw was evident, but nothing affecting the bore, combustion chamber, valve seats, or gasket surfaces short of a knick in the edge of the timing chain passage on the cylinder. Still nothing that would be a detriment to the workings of the engine. The kit itself has a dished piston roughly 8 grams heavier than stock, and the head appears to be a stock sized casting (39mm chamber) where they roughed out a squishband bevel 2mm deep to bring the head's combustion chamber out to 50mm. Also the valves were assembled with twin springs. My stock head only had single sprung valves. The A9 cam looks great, it even has 8 additional holes drilled around the timing gear to lighten it. I made a couple small errors though. First, i didnt order new intake or exhaust studs. Easily remedied though by fetching a pair of M6-1.00x100mm threaded rods from the big box hardware store and cutting them for 32mm long exhaust studs and 63mm long intake studs. Second error, i could have sworn a million times over that the schwinn's stock head was 69mm valves. (I did use the stock head on the 47mm bore for the last 2000 miles.) Well i ordered the 50mm bore kit with the 69mm valves but it seems i was mistaken. I got lucky though, the engine i bought from jbjhillbilly had 69mm valves - and rockers! So i grabbed those and they fit perfect. Assembled, set valve lash to 3mm in, 4mm ex, filled with rotella t4 15w40 diesel oil, cleaned the carb and dropped in a 90 main jet and a fresh ngk c7hra plug. Kicked it a couple times to get the fresh oil moving, then fired it up. Rough set the carb mix and idle, let it idle 15 minutes, and then tuned in the mix and idle. 2 miles at 10mph, then 15 miles slowly varied throttle positions, then 10 miles straight wot. During the breakin time, swapped up to a 96 jet. I havent adjusted the cvt yet. I just got back from a 40 mile evaluation ride. I feel a slight improvement on 0-20mph pulls, feels more connected at clutch engagement and pulls right away from a stop. The 47 had a slight sluggish pull from a stop, and though it was an improvement over stock 0-20, it's only benefit was holding power into the wind or up hills. The 50 kit holds a steady 38mph into 12mph headwinds AND up the steeper hills minnesota has. Which is nothing compared to the foothills around tennessee. I had a max gps tucked downhill with the wind at 45.61mph, and i averaged 41mph. Even in a stock cvt configuration, i'm quite pleased with the upgrade. A couple more notes. I did finish up the install just today with 3991.2 miles on the odo-clock. The evaluation ride was done between 2-4pm during a midday heat of 93F. I've been smelling slight... burning oil... but they wouldnt have sent me an assembled head without putting in the valvestem seals... would they have? If they did install the stem wipers, why would they send an extra set? Just cuz? Nothing else really to report, but any thoughts would be appreciated as always! |
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Post by AtariGuy on Aug 15, 2018 1:37:01 GMT -5
Ride update - rode the red machine to work and back. With the cool night air, it was a speed machine! I had a tucked average of 46mph and regularly saw 48, once to 50. I'm also noticing it's a little snappier off the line, it loads the clutch up well and has the torque to go when it needs to. Even found myself having to back off the throttle in town cuz i'm not used to it being all there!
But i know there's more to be had from a big bore. 120 miles in and it just seems to be filling in the gaps of an otherwise stock setup cvt/gears. I should have detailed some measurements of the compression height of the piston and checked the cc's of the dished piston, but i was a very eager beaver to get this up and running. I think my next plan of attack is to tear back into it, check the current compression ratio with both gaskets, then look at valve clearances and compression as i remove gaskets. As long as i dont have interference anywhere, i may just go with gasket compound instead of the included gaskets for the highest compression. Or swap to a higher compression domed piston...
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