Yamaha YZ65 2018 - Carb Testing - Bog or Starve?
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- Опубліковано 2 жов 2019
- Problem Statement: my boy complained of the bike cutting out as he went up hills.
I managed to replicate in the garage.
Bike also wasnt that crisp on the throttle when warm so, changes made:
1. checked lean/rich status - Looked like it was running rich stock (confirmed by the interwebs as common)
2. changed main to #135 crispness much better, started to stall when throttle opened quickly
3. went back to stock. all problems still present.
4. changed back to 135 main, and changed needle position to top most (1st). throttle crispness (idle & blip) ok. open throttle quickly and stalls
5. changed needle to 4th position (stock is 3rd), throttle crispness great. open throttle quickly and still stalls
6. fettled with the float.. carb flooded/overflowed. return to standard. 19mm float rise from seated. still stalls on ripping open.
Is this just how 2-strokes run? I'm a 4T guy.. is it just a case of keeping the revs up?
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Filmed on GoPro Hero5 Session - Авто та транспорт
That. Noise. It. Gives. Me. Nightmares.
From running these on a dyno a lot and having this issue with one of our yz65 bikes before we found mainly they have to be put on a 50 pilot for most and now a stock bike with no mods we found (in uk with stock fuel ratio) loved it more when we had 50 pilot 5th clip on needle (the richest) and a 148 main they are day and night difference the main issue is the 28mm carb
Teamgabbymx
We have a 2020 yz 65 no mods it has a 48 pilot and a 150 main in it atm
I also have a 142 main which main jet would you run and should I put a 50 pilot in it on needle clip 5 ?
Dude just kick started the bike with his hand 💪🏻
🤣🤣
same dude
I do that sometimes with my Honda crf70 and I’m only 12
It's a 2 stroke and only 65 cc.
Just like a chainsaw.
I cold start my Honda NSR50 with my hand since I have to bend down to fold it out anyways
Sounds very lean up to 1/4 throttle. I’d suggest richening up the pilot jet & fuel screw. 2 -2.5 turns out on screw is ideal, any more or less swap out your pilot jet.
2-strokes have air screws.
It's the pilot screw.... Last one ....only 3 places to adjust
Sounds and acts like a float bowl issue when you tilted the bike in an "up hill" position so I would look at that after ajusting air-screw and idle-screw first. Set the float to the correct position (most likely stated in the manual). When you gave it throttle on the first go and it bogged out hard with the bike in the horizontal position which generally means it's too lean, adjust the clip on the needle to a lower position like 2-3. even before that id only adjust the air screw and idle screw first to get it to idle smoothly.
It was the pilot. upped to 50, ran perfect then
@@keepy6969 Awesome, glad you figured it out... for what I did see of the video it did seem like it was float issues.
Happy riding mate 👍
did you ever figure it out? I got the same problem.
Just got a 21’ yz65 set up for a sponsored racer. It has the same bog. I’m guessing it’s ok as long as they are ripping it and modulating power with the clutch? Also, the dealer said idling too long or a bad spark plug will def affect this. Seems like u got it figured out with main jet to 50. Im running 36:1 fuel.
Had a bad coil on my ktm 250sx. Would run great as I ramped the fuel. But hard throttle it would bog down. New lectern carb new reeds rebuilt top end still same. New plug new air filter still bog. Turned off the lights in the shop and gassed it wide open and the coil looked like a Christmas tree. Fixed $1644 later and is now a beast
How exactly do you tell if it’s the coil? My cr125 runs great except from idle it wants to bog
@@user-pt1hz2wz7h sounds like the wrong idle jet or mix is off a little.
How do you fix bogging that's only in the low end and it idles okay mid-range and top end are okay
If bogging in low range clean the low idel jet(usually is the smaller one) there's no need to interfere with the pilot screw(s).
did you check the air screw position?
It was the pilot. upped to 50, ran perfect then
That looks rich. I know it is a old video but that seems like a rich bike. There was a lot of exhaust coming out. What did it end up being?
Too lean on the Pilot
Did you ever got it to run good and what was the problem? Scratching my head also on this one
yeah, I got it running spot on in the end. It was WAY too lean on the pilot, and too rich on the main
@@keepy6969 what did you end up having it set up as in the end?
@@advennturesinalaska Main = 135
Pilot = 50 👍 absolutely rips after that.
@@keepy6969 nice, thanks. I just got the 65 a couple weeks ago. Did the extra jets come with the bike or did you have to order them?
@@advennturesinalaska had to order them, they weren't much £ though from memory. that said! they arent 'much' anyway! 😂
Gas was off when u took the plug out
Rich
sounds like to much fuel at the top. maybe the mainjet is too big causing to bog.
It's sparkplug i have same problem with 125 4 stroke
It was the pilot. upped to 50, ran perfect then
But yours on the uphill deal only is always to much fuel. The carb sets tilted and once level the float opens and makes to much fuel. Could be the float itself needs adjusted. Or low octane gas
Reed valve
Pilot to small. wasnt reed valve.
That's the float position!
Would it be to high more fuel . Or to low , not enough fuel?
@@luckyaffpv343 to high float level, to much fuel!
@@RafaZardetto115 10-4 but with a bog when full throttle . Would you think its to much fuel or not enouh
@@luckyaffpv343 it could be both depending on the way the bike sounds, check the spark plug to know, too black too much fuel, un burnt oil too much air, start by tightening the air screw all the way, then loosen until bike sounds better, then adjust the idle screw to a perfect position not to loud or to quit, if none works, clean carb check float height and check the holes on the jets, or replace air filter if bike keeps getting clogged, Cheers and take care
@@AF.256 thanks.