Engine bogging down while warm, like it's misfiring

[SneakyDingo]

My bike is under-500 mi new, and lately has developed a habit of occasionally slowing down suddenly and then rejoining the conversation, usually under acceleration but not right at the start of the acceleration. Like it'll be accelerating for about a half second, suddenly bog down like it's misfiring, and then resume like nothing else happened. There's no pop noise or anything, it just stutters and then keeps going. This is while warm, like after 20 minutes of riding.

I haven't done anything to the bike since new other than adjust the automatic clutch, which I'm pretty sure is not the cause since the transmission is fully engaged at that point. Any ideas? The only thing I can think of is "bad fuel" since I didn't fill up at my normal service station.

 

[m in sc]

very possible fuel. no other reason it should do that,

 

[Carolina Vagabond]

Yep, that’s the first thing I thought too while I was reading your post.

 

[Kritou]

Temporary fuel starvation ie partially blocked tank breather or kinked hose?

 

[SneakyDingo]

Temporary fuel starvation ie partially blocked tank breather or kinked hose?

That's a good point, I didn't mention the fuel level. Fuel is still 2 bars on the fuel gauge. Not sure what would cause a partially blocked breather or hose other than insects, tis the season for them being annoying and building in random locations, but I'd assume the malodor of gasoline breathing would be enough to dissuade them from trying to build a nest there.

The other thing I didn't mention, because I didn't think it to be super relevant but it's very much a "maybe" is that I used Premium fuel last time. Specifically I filled up with this stuff (yes I take a photo every time I fill up at the station, it's habit).

EDIT: Honda manual says on pg 93 this should be ok for ethanol % so it's probably not that, which was my only other guess.

 

[m in sc]

87 to 93 is fine ethanol or not either way, thats not the issue. quality of the fuel from that station might be. ie: water in the ground tank.

 

[SneakyDingo]

water in the ground tank.

I did want to make sure that I was ruling out "Not Honda approved" reasons. I strongly suspect that I should run this tank close to empty / all the way to empty, and then fill it with love from my usual station.

 

[m in sc]

ive run mine on some real swill, no issues. they arent that picky. water however is a no go.

 

[Carolina Vagabond]

ive run mine on some real swill, no issues. they arent that picky. water however is a no go.

Spot on info right there. 87 is fine but water ain’t.

 

[wadoii]

Recommend check for carburetor issues, clogged air filters, and corroded spark plugs. Those are the main reasons why your dirt bike is bogging at full throttle. Poor jetting, the engine isn’t fully warmed up, or the accelerator pump are also secondary reasons that lead to dirt bike bogging.

 

[Plotus]

Curious..... I wonder if ..........is the 2023 honda ct125 fly by wire?

 

[oldskool]

If the gas tank has been overfilled the EVAP canister could be soaked. I've been told this can cause venting issues and lead to fuel starvation under load Unless you live in commifornia the fix is easy

 

[Kev250R]

If the gas tank has been overfilled the EVAP canister could be soaked. I've been told this can cause venting issues and lead to fuel starvation under load Unless you live in commifornia the fix is easy

Even here in the Golden State the Charcoal canister can be removed; there are no Smog or other inspections for motorcycles in this state.

 

[Shoot870p]

Recommend check for carburetor issues, clogged air filters, and corroded spark plugs. Those are the main reasons why your dirt bike is bogging at full throttle. Poor jetting, the engine isn’t fully warmed up, or the accelerator pump are also secondary reasons that lead to dirt bike bogging.

Not to sure about the jetting or accelerator pump on these. On a stock engine the Emi probably does a “decent” job

 

[Cardinal Direction]

Mine did the same thing on a tank. Ran it dry and got more gas and she is back up to snuff. Mileage was piss poor on that tank too

 

[AZ7000']

We are talking about the fuel injected ct-125?? Right?

 

[Shoot870p]

Possibly, but with the optional cold weather carburetor .
just had to. Sorry.