Need expert help on installing walbro carb...please help !!!!

salorr33cc

Member
Apr 30, 2016
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pennsylvania
Cool Steve,,, thats awesome thank you
I would love to talk to you more when I get back from hardware store...Got an Awesome upgrade working on and if it works I will be selling it in a kit,,, Its what these bikes need !!!

A WALBRO WYK -192 15mm carburetor with HIGH and LOW speed adjusters,, I have the adapter / heat insulator intake mount (hard plastic/composite ) that has to slightly be modified to work,,, also there is a pulse hole on these carbs since they are diaphragm type and I need to find a way to connect it,, these carbs are also used on the 49cc 2 stroke scooters (( I HAVE ONE, THATS WERE I GOT THE IDEA)) on those engines the pulse hole connects to the engine thru a hole underneath the intake opening on cylinder..

If you look thru the tiny pulse hole opening right under the intake flange opening you can see the piston skirt going up and down creating an open / shut action as it passes by tiny hole..

I am trying to figure a way to hook up pulse hole and where too... I can hook up a little brass elbow tube coming out of isolator block ( as shown in picture)) ,, but where do I run a tube on it too...???? I saw one guy on here that ran it to a small nipple/tube fitting that was drilled and tapped into the transfer port on the bottom left of engine,, below cylinder where the cylinder meets the bottom case transfer port.. into the case wall thru the transfer port...

will this work and give it the pulse it needs ???? please help me with this Steve or anyone that is familiar with this...please!!!

If this works it should be like fuel injection,, as on the scooter there is no 4-stroking and screwing with main jets and needle clips... i got this Walbro WYK-192 off a brand new 72cc industrial leaf blower engine,,, so should work on 66cc... will try to get a bigger 18mm diaphragm carburetor in future if this works out good..

THE PICTURE OF CYLINDER IS THE INTAKE FLANGE ON THE 49CC SCOOTER ENGINES,,, SEE THE SMALL PULSE HOLE IN BOTTOM/CENTER... THIS IS OPEN AND SHUT BY THE PISTON SKIRT GOING UP AND DOWN OVER IT..
 

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Tony01

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Nov 28, 2012
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Yep transfer port on bottom left. If you don't wanna use the pulse fitting just plug it off for now.
 

salorr33cc

Member
Apr 30, 2016
49
0
6
pennsylvania
Will a WALBRO 192 CARB even work and make the bike run OK the way it should if you PLUG up pulse hole....seriously..?????????????

I thought the pulse hole was to get timed engine vacuum to pulsate and move the diaphragm up and down acting as a fuel pump..!!!!!

Also what do I do with the fuel return line coming off CARB.... can I just run an over flow tube off of it and routed down on bike......or do I have to connect it into the fuel line with a one way check valve....?????
 

salorr33cc

Member
Apr 30, 2016
49
0
6
pennsylvania
How do i get to Fabians video's ???? I think I saw a few on youtube,,, does he have an accent when he talks..???? Well I am real Awesome at tunning the WALBRO CARB's... I had them in mt weed wacker's,, 1/5 scale R/C CARS and TRUCK's,, in mt 36cc and 49cc scooters and pocket bikes,, so I am good with the HI / LOW screws...The hardest part is the initial settings cause if one is off by a half turn it wont start...

Electric start is nice to have to find the initial start up settings cause you can turn screws while you are spinning over engine..I am going to have to adjust then pedal,,,,adjust some more then pedal,,, adjust some more then pedal...BBRRRp BBRRRPPP BBRRBBRRBBRR there we go !!!!! then its warm up and take choke off adjust idle a little high,, then LOW speed screw back out until it burbblleess and runs rough then 1/3 turn in opposite direction....

The HIGH screw is lift or raise back wheel off ground and hold throttle WOT wide open and turn HIGH screw clockwise (in) which LEANS the air/fuel mixture out and listen for the engine rev's and RPM"s to increase to MAX where it is screaming and then back it off counter clockwise 1/3 a turn,, then re-adjust IDLE screw,,, and there YA GO...!!!!

Then do (2) plug chops,, one for low-mid and two for TOP end,,, you then can back off a little on LOW speed screw to get it to run a little rich and if you can get it to 4-stroke on demand just a hair little bit,, like going down hill with no load is even better cause 4-stroking richness will help cool the engine down and lubricate it better with the extra oil going in...

It should run smooth as butter from Idle to MAX RPM (10,000) with no problems.. I have a Tachometer and I cant get it past 8,000 rpm at 34 mph with the 44 tooth rear sprocket,, I am a light weight 150lbs,, and I have plenty of low-mid range power between 3,000--6,000rpms which is starting off,,, hill climbing,,,and cruising speed at 25--28mph...

I do have some steep hills and long distant inclines around here where I live,, but then some nice back country flat roads also that I want to cruise fast on..!!!

So my question to you is should I go with the common 36 tooth for 8 mph top speed increase to 42 mph max and 32 mph cruising speed,,, or go with the other common 40 tooth for a little more speed and better low-mid power and 38 mph top speed,,,.. OR WHAT I FOUND was some one that makes a 38 and 39 tooth, 40 mph top speed...

I think with the NEW CARB setup and hopefully upgrade to a 18-19mm WALBRO (if they make one)) I cant find a diaphragm CARB bigger then 15mm.....DO YOU KNOW WHERE TO GET ONE ???????.... and put a Dirtbike KX 65 Pro-Circuit Torque pipe which exits into (2) two short stubby silencers and RSE REED CAGE setup with Piston windows (ports) and intake side cylinder 3rd transfer port like on the GT80 engines that will give it the extra LOW-MID power and 2,ooo extra (10,000) RPM's needed to pull the 36 tooth sprocket nicely topping out at 45 mph......WHAT CHA THINK BOSS ..???!!!

HEY one last thing to answer for me,, your opinion ???? If i do a good job and done right the best way,, custom installing this 15mm WALBRO carb and a 5mm half moon or flat squarish cutout on the piston skirt intake side where it over hangs the intake port by 2mm at TDC and then take my Chrome Banana expansion pipe that I have on there now and add a 2"--3" inch header pipe *((should give me more LOW end torque))** and last but not least RETARD the Timing a few degrees, like 2-5 degrees only with my woodruff key that I filed a little off on the top half**((the untouched stock magneto already has a few degrees SLOP in it to begin with))**..........Do you think doing all this will give me a big noticeable POWER gain thru out the whole RPM range and have the POWERBAND HIT to come on earlier ....The PIPE dont hit until about 6,000 rpm's now,,,way to late......YOUR OPINION IS--??????????

SORRY about being so long and much but please anyone that knows there stuff ...please help answer all my questions,,,!!!!!!!!!!!!!!!!!!

Currently have the GT5 47mm X 38mm 66cc engine with *** 202 bearings and needle wrist pin bearing with the short type A piston with the wrist pin in the middle and .60 dome top,,, real nicely done perfect bottom case and gasket port match to cylinder which has a extra thick base raising my exhaust and transfer port duration/height timing. can still probably use another base gasket to go even higher but will lose my 1.2mm squish band using one aluminum head gasket on the RSE compression round 6cc Billet Head...

Have the rest of the cylinder ported and polished a hair and casting flaws cleaned up, little extra wider on exhaust port and raised 1.5mm and mirror polished,, little extra wider intake port and scuffed for better fuel atomization,,, just took casting lip off on transfer ports only,,,NO piston mods done yet..

An exact 66cc volume Awesome custom built BOOST bottle with wide 3/8" 4"inch hose with drilled out and internally flush 3/8" fittings,, .65 main jetted NT carb with thicker 4 clip needle in the top position, .05mm back bottom of carb slide sanded down((leans out idle better)) and lean/low float 23mm adjusted forks and O-ring sealed.... shorter 8mm shielded copper core spark plug wire and NGK cap and NGK B8HS .030 gapped plug..... 96 octane sunoco fuel w/Bel Ray synth. oil / 32:1.....and a Chrome Banana Expansion Pipe !!!!!!!!

Custom Turbo Kit to come soon,,,, Right after Ram Air intake kit......Lol...LOL Thanks Guys for baring with me and reading all this,,, Look forward to your REPLY's....

can you plug up pulse hole on Walbro and have it still run right..?????
 
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Flight Risk

Member
Jan 25, 2010
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Hey all, I've been thinking of doing a Walbro mod too. I'm wondering if that pulse setup is needed since we would have gravity fuel feed and not need a pump. But since there is a fuel return line would we need to pump fuel back to the tank? or would it flood? I've heard elsewhere that you can get pulses directly off the intake, but that seems too easy.
 

salorr33cc

Member
Apr 30, 2016
49
0
6
pennsylvania
I have come up with a easy bolt on Walbro WYK 192 15mm adjustable HI and Low screws conversion kit that I am selling to any one who finally wants to get rid of Carburetor issues..

It is like fuel injection,, no more 4-stroking and revs to the max..

You need to just drill and tap fitting in case and connect to composite isolator adapter...

listen,, I am going to open a new thread on this with more detailed pictures and detailed info,,, I have put a lot of time and effort into this to make it better and cheaper for people ,,

i am thinking around $60 for everything except air filter and velocity stack with choke..look for my thread later today in general discussion,,, i also solved all the issues with the pulse hole and fuel return...check it out later