[adrian]

The air filter compartment of UCE 350 bullets were badly designed. The reason for this is that the UCEs had paper type air filter element and for some reason, the design was in such a way that the hole through which air was sucked into the air filter compartment was placed right above the air filter element, resulting in the filter getting soaking wet during ride in the rains. This in turn caused misfires.



The remedy for this is actually very simple.
Buy a radiator hose (bend type), the one for the Ambassador car suits well.



Apply silicone sealant on the hose and insert it like in the below pictures





What this does is that the water that gets sucked in during rain falls on the corner of the air filter box and gets drained through the drain hole at the bottom. The result is that the paper air filter element stays dry.

I have been using this juggad for over 7 years and rode my bullet to Ladakh and back, with good results.

regards adrian

[Aditya]

Thread moved out from the Assembly Line. Thanks for sharing!

[tharian]

Good idea.

Is the water getting in from the rear wheel or elsewhere? This is the same set up on my 2002 Bullet Electra, but I haven't experienced water getting inside the box till date. There is an inner mud guard for the rear wheel too which prevents this and is smaller in size compared to the later models.

[ebonho]

Simply change your system to the old style chrome air box and free up you right side tool box.

Cheers, Doc

[adrian]

Originally Posted by tharian

Good idea.

Is the water getting in from the rear wheel or elsewhere?

The water entering the air box is not wheel splash. There is a plastic mudguard there separating the opening from the wheel. Riding in small rain does not cause the filter to get wet. But if you ride in a downpour, the filter will definitely get soaked. If you look at the following photos, you will know why.

Originally Posted by ebonho

Simply change your system to the old style chrome air box and free up you right side tool box.

Cheers, Doc

Doc, the CI bullet in our group has the chrome air box setup. It is simple and easy to maintain. But as far as dust/ moisture entry is taken into account, the UCE type with an expansion chamber in the middle is better as it is a better sealed unit. It is more silent as well. The only flaw is with the filter getting wet.

Edit : One more thing I learned by riding in a cloud bust in 2017 is not to take the motorcycle to high rpms while the paper air filter is soaked. At lower rpms, the moisture content gets eliminated at the expansion chamber. But if you twist the throttle, water will enter the carburetor, causing the motorcycle to stall.

[ebonho]

Originally Posted by adrian

Doc, the CI bullet in our group has the chrome air box setup. It is simple and easy to maintain. But as far as dust/ moisture entry is taken into account, the UCE type with an expansion chamber in the middle is better as it is a better sealed unit. It is more silent as well. The only flaw is with the filter getting wet.

Okay bro. You do realise its a very restrictive system? Even my LB and my 2002 Bullet 500 had the same filter system. Changed them immediately. You can literally hear and definitely feel the difference. Like someone has taken a big potato out of the bike's throat. I recommend this more than a muffler change. Not only does your filter get wet, and makes useless one tool box, it also gets clogged with oil from the stupid vapor condenser. All taken off and never used again.

Cheers, Doc

P.S. Are you sure water is the issue, and not an oiled out filter? I suspect that.

[adrian]

Originally Posted by ebonho

Okay bro. You do realise its a very restrictive system? Even my LB and my 2002 Bullet 500 had the same filter system. Changed them immediately. You can literally hear and definitely feel the difference. Like someone has taken a big potato out of the bike's throat. I recommend this more than a muffler change. Not only does your filter get wet, and makes useless one tool box, it also gets clogged with oil from the stupid vapor condenser. All taken off and never used again.
Cheers, Doc

Yes Doc, agree with you 100%. But the new constant velocity carburetors are not rugged like the flat slide ones. Need to protect them from dust and moisture as scratch on the slide surface or the body means a carburetor replacement.

There is no oil issue. You can see it from the picture in my first post. The small hole (crankcase vent) on top of the filter box is clean. Also the UCE don't spit oil into the air filter box through the breather pipe unless the engine is grossly overfilled with engine oil. When the filter used to get soaking wet, the motorcycle would stall and when the carburetor float bowl was removed, there would be water content. Water droplets would also be found on the mouth of the carburetor.

[AddyGator]

Airbox jugaad mods are one of the most underrated things you can do to any RE 350! be it older ones or new j series engines. I modded my airbox too by getting rid of its intake snorkel and the difference was very noticeable.

[ebonho]

Originally Posted by adrian

Yes Doc, agree with you 100%. But the new constant velocity carburetors are not rugged like the flat slide ones. Need to protect them from dust and moisture as scratch on the slide surface or the body means a carburetor replacement.

Nothing happens. If grit is getting through, the carb is the least of your worries. Trust me.

My Machismo 500 had a CV carb, before I moved to a VM28.

The Bullet 500 had a VM28. A round slide. Not a flat slide. The flat slide keihin was used for racing only.

Your bike, your choice. Keep it simple. Dont fix what aint broken.

Happy to know that oil was not the culprit.

Cheers, Doc