Kart Racing Pro Official Forum

General => Off-Topic => Topic started by: Keagan on July 25, 2016, 01:17:43 AM

Title: New to karting :Yamaha t100 motor, won't start
Post by: Keagan on July 25, 2016, 01:17:43 AM
Bought the kart for my grandson to step up from the yard kart. He was power sliding it since he was 5🌝
Previous owner said hasn't been started for "several years". 
I've drained the tank, filled with 50/1 mix
Initially disassemble the carb: all parts looked good, cleaned in ultrasonic unit, but still no start.
Bought new kit,, installed all new diaphragms etc, no start
will fire with a shot of premix into the air cleaner
New plug ,  got good rich fire
Compression test reads 60 psi
Plug looks "wet" after attempts to start
I note that the H needle does not have the o ring, washer that shows in manual ( did not come in new kit either)
I'm new to these little 2 strokes, but pretty experienced wrench over all
Any thoughts?   
Located in Southern In.
 
Title: Re: New to karting :Yamaha t100 motor, won't start
Post by: karterjames22 on July 25, 2016, 12:29:19 PM
this is a forum for a karting game not actually karting
Title: Re: New to karting :Yamaha t100 motor, won't start
Post by: EVO on July 25, 2016, 12:39:17 PM
Do you mean the KT100? They sometimes dont fire right up immediately. You have to prime the carb and hand choke a little sometimes. Once it took almost 7 seconds on the handheld starter to get it going.  Also maybe your ignition system  is bad/poor timing?
Title: Re: New to karting :Yamaha t100 motor, won't start
Post by: Taddzy on July 25, 2016, 05:20:46 PM
Quote from: Keagan on July 25, 2016, 01:17:43 AM
Bought the kart for my grandson to step up from the yard kart. He was power sliding it since he was 5🌝
Previous owner said hasn't been started for "several years". 
I've drained the tank, filled with 50/1 mix
Initially disassemble the carb: all parts looked good, cleaned in ultrasonic unit, but still no start.
Bought new kit,, installed all new diaphragms etc, no start
will fire with a shot of premix into the air cleaner
New plug ,  got good rich fire
Compression test reads 60 psi
Plug looks "wet" after attempts to start
I note that the H needle does not have the o ring, washer that shows in manual ( did not come in new kit either)
I'm new to these little 2 strokes, but pretty experienced wrench over all
Any thoughts?   
Located in Southern In.


if you say the plug looks wet you could be bring to much fuel through the carb causing the engine to flood!! look up yamaha kt100 carb settings and then adjust your carb to what is recommended on the top and bottom end jet
also is worth making sure that you are getting a spark from the plug but always remember to put the plug into the cap before cranking the engine as that can cause the coil to fault as i have learnt!!
Title: Re: New to karting :Yamaha t100 motor, won't start
Post by: Keagan on July 26, 2016, 03:19:14 AM
I've got good spark. Carb settings are:  H. 1/8 turn out.  Low is 1 full turn, based on Walbro factory rebuild instructions
Title: Re: New to karting :Yamaha t100 motor, won't start
Post by: EVO on July 29, 2016, 08:28:07 AM
You can do a simple spark test by turning if over with the plug out but connected and held against the fins of the head.  Hold it on the rubber end.  In low light you should see sparks.  I be done this test on, karts, pitbikes,and dirt bikes.  If you have spark than it must be the timing.