i have a 2010 300 4t... its 4 months old and the inlet rubber has split open... not really a material defect just whoever put the carb on in the factory didnt align it to the inlet manifold and its been straining the rubber until it let go

you can see on the next image how the rubber isnt on straight anyway

so if you own one it might be worth checking your not in the same situation or i might just have the friday afternoon bike

just hope lampkins have one now

That's jacked up. It's clearly not lined up properly and unless corrected will probably tear another boot in no time.

Didn't have that problem, but mine had a split in the little rubber cap that pressed down on the vent tube, that points straight up, right next to the large black cap over the CV chamber. Assume this vent is to connect multiple carbs together. At any rate, messed up how the bike ran, so keep an eye out for that one, as well.

That's jacked up. It's clearly not lined up properly and unless corrected will probably tear another boot in no time.

that was my point... the fact it was way out of line... its the way it left the factory and i didnt notice or look for it.. obviously as airbox etc is off to remove the old boot i'll realign it when i fit a new one, looks like you gain alignment from the connector pipe from the airbox to carb? cant see another way of getting it at a different angle.

I have a 2009/250 4T, and I had the very same problem. The inlet rubber slipped off very often and I had to reinstall it at least once a week. Finally it broke.

In my case I think misalignment was not the only reason for inlet rubber breakage, but there was a defect in the part, too. You can see it in the pic below; too smooth tear area to be a perfect inlet rubber?

At the time it broke I could not get a new inlet rubber for several days. I went to a local technical rubber products selling store and bought a piece of a cooling system hose. I made it almost 10 mm longer than the original inlet rubber to make it sit better in it's place and get rid of the stretch.

A beginner like me does not feel any difference in power delivery, how the engine reacts or in anything at all. The only difference is that I don't have to reinstall the inlet rubber weekly any more.

I do have the original part now, but I don't put it in until I find the reason why there is such a misalignmet. In the pic You can see how misaligned carb bends the hose.

Reckon it's the part between the airbox and the carb that is not perfectly in it's place and misaligns the carb. Maybe it's too far from the carb, too and thus stretching the inlet rubber? I'll fix it when it's too cold to drive in January.

what diameter is the rubber between the carb, airbox, engine ?

mine started slipping off whilst riding last week managed to get it back

on but was thinking about making one myself slightly longer

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