Modern Buddy

I had the most miserable ride home last night in 43F rain (thankfully light), largely due to the fact that my engine kept sputtering and dying on me. The facts:

1) The battery is near the end of its life cycle, but I plug it in every night and it started up just fine when I left the office

2) After about five minutes/one-half mile (rush hour, after all), the engine started to sputter a bit. Giving it more gas made it feel like it was going to stall. When I backed off, it idled, but poorly. I pulled over onto the sidewalk and, after a minute or so, it sprang back to life and ran fine when revved.

3) Made it another half mile before it started sputtering again. This time it sputtered out. Started it up again.

4) Repeat this process four more times before making it home with a stop at a gas station with a shelter to do a once over.

5) There's little compression in the kickstart lever.

6) Pretty new plug (NGK C8EH9) that's a nice gray/brown color.

7) Oil changed on Sunday without incident and I re-checked all the nuts and oil level.

Thoughts?

fuel filter? could be getting clogged.

Did you just fill up, could be a flooded EVAP system. Sounds like fuel starvation, could be clogged fuel tap, fuel filter, carb needle valve, gas cap vent (if you have a vented gas cap), kinked fuel line, flooded/clogged EVAP.

Neurotic-Hapi-Snak wrote:Did you just fill up, could be a flooded EVAP system. Sounds like fuel starvation, could be clogged fuel tap, fuel filter, carb needle valve, gas cap vent (if you have a vented gas cap), kinked fuel line, flooded/clogged EVAP.

No EVAP system in place. Got it like that. No, really, I did.

Last fill up was last week and am at half a tank now. I'll start checking the fuel line and make sure that gas cap is properly vented.

Thanks, gents!

It was still miserable out last night and I don't have a garage so I didn't check the fuel line, but it occured to me that my air filter (one of those aftermarket RAM ones attached right to the carb) was a bit damp from the splash up on the road. I didn't think much of it (it wasn't THAT damp) but it might have been sucking just enough moisture into the carb (and then into the engine) to make it run poorly. Note the engine ran just fine when it was sitting still and didnt' start acting stupid until I was in motion on a pretty wet road for a few minutes. I've ridden in a drizzle since I changed the filter out but this was the first time I was out in actual rain.

I have my father-in-law's birthday dinner tonight right after work and then our monthly scooter group meet up, so hopefully I can take a peek at it tomorrow night, when it will be dry...cold, but dry.

Stilts, if the filter got soggy, you might be able to use this in its place:

https://www.treatland.tv/44mm-foam-air- ... 810-44.htm

I picked up Polini filters for Dell'Orto carbs that has shields on them, haven't installed on a 4T yet but they work well to keep the filter dry on mopeds:

https://www.treatland.tv/polini-mikuni- ... 3.0082.htm

Not the fuel line. Everything appears clear and free. Still replacing the fuel filter, though, with an aftermarket one I found about on here somewheres. Ran just fine in the dry air. More than ever I'm convinced it had something to do with the rain. Just avoiding wet weather now until it gets warm enough out.

However, the shoulder of the RAM air filter I purchased back in October cracked halfway, leaving a bit of an open gap, which makes me all the more convinced water got into the carb. I'm getting the 22mm Polini carb for Christmas (gift to myself, along with the GPR exhaust) so I'm holding off on a full replacement air filter thanks to some sealant and some gaffers tape. Anyone know what size the air intake on that 22mm carb is?

38mm