Linhai 300 and rain problem By john11v35 (Read 1,731 times)

[john11v35]

I have a linhai 300 with the Dragon Custom Double Shot exhaust, intake and oil catch.
It has been re-jetted by the dealer (not sure to what since it took several 'tweaks') and an electric fuel pump was installed to alleviate fuel delivery problems due to all the new air that was being pushed through.

Ever since the new setup the bike will only run about 10 minutes in rain. In dry weather, it runs fantastic. After about 10 minutes, the scooter loses power, the RPM's drop and it will idle but will chug and die with any throttle input at all.

After being towed home the second time I got caught in rain, I'm looking for some suggestions to see what I need to do to keep the motor running in the rain.

I am guessing that the intake is sucking water to the filter which is getting wet and no longer allowing air through thus creating a rich condition.

So, any ideas on how to keep the intake from sucking water? The dragon exhaust company suggested putting an athletic sock over the end of the intake. I haven't tried that yet since I was hoping for a more informative/creative answer on what I could do.

Some of my thoughts are to somehow add an extension to the intake pipe that would pull dryer air, while another is to find some sort of pre-filter that would fit over the end of the intake.

Thoughts?

**edit** It ran fine in the rain before the mods.

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[JR]

Wow this one is a new one on me! This scooter must be pulling some air to pull water in! Is it possible that the air intake housing is running uphill and as water runs down the side when it's raining it's falling off the end of the intake housing and heading right to the carb?

Is it possible to get a more full view photo so we can get a better idea of how this system is mounted?

Even if a sock of some sort will cure what's wrong it'll have to be a very thin one or you'll end up re-jettinmg again because of a loss of air volume.

Got to study on this one!

JR

[speedracer]

I would ask if the air filter is an add on and exposed such as a UNI or is it sitting in the air box.

[john11v35]

I don't have any pictures with me tonight, but I'll post a couple from the vendor's website. I'll take my own pics tomorrow.

I can tell you that the air filter sits about 2 inches behind the top of the intake in the large "can" area. The filter itself looks like a K&N style, but it obviously isn't.

You can see a couple of hex bolts that you remove to get to the filter on the can just past the logo towards the tip. I can also tell you that there is an elbow that goes up about 20 degrees to where the intake attaches to the motor.

Also, here is the shop 'testing' the new exhaust.
.facebook.com/video/video.php?v=376774735846" rel="nofollow" target="_blank">.facebook.com/video/video.php?v=376774735846

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[john11v35]

Second vendor pic.

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[JR]

The second picture at least gives me an idea. The video doesn't even show the air intake except the end for a moment.

But the second picture gives me the impression that it is mounted with the tail end slightly elevated which would make the unit run downhill. Now as a fabricator I see another thing and that's the angle cut on the end pipe.

The theory here is that water will drip down and miss the bottom half of the pipe and it should do that but if the unit is heading uphill you lose this option.

Another question? Where is it put together are the connections good and tight? You possibly could take a water hose and turn it down to a slow stream and run water over the unit for a good bit and then dry the outside well and then pull it apart to see if it's dry inside? If not then sealing it is going to be the answer.

JR

[john11v35]

In this photo, you are looking at the intake from the rear. You will see that there is a lip of about 1/4-1/2 inch welding inside the intake pipe which I assume is to keep the water from running inside.

The circle in the middle is the actual air intake area and the silver/chrome piece that you see inside that hole is the top of the air filter itself. It is a cone shaped filter similar to what I run in my little 4 banger.

The two lines on the right side of the photo show the intake where it runs into the motor itself. It isn't angled as steeply as I had thought it was. I would say the angle is only a degree or two at most.

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[john11v35]

In this photo, you can see the angle of the intake, except the bike is on it's center stand and the back wheel is off the ground. If you take that into account, you should realize that there would be a slight downward angle to the intake from nose to tail.
I also noticed a rubber grommet in the photo that I hadn't noticed before. I assume it's for bikes that need a MAF sensor or something similar. I'll look tomorrow and see if this has a hole in it all the way through or if it is a cap.

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[john11v35]

In this photo you can see the intake color change from chrome to the black rubber boot that connects onto the motor.

You can also see that black grommet which is probably for a MAF sensor or something that works on another bike. I'll check to make sure it is solid and doesn't leak water.

The connections are tight. I once had the intake boot loosen off the motor while I was riding so I check it, the hex bolts, and the mounting brackets periodically to make sure they are all tight.

I'll give the water test a try and see if I find any water inside. This will also give me an excuse to show you the inside of the intake.

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[JR]

Great pics John!! You're right on as far as exploring that rubber cap and let me ask you this? Those pop rivets are they tight and the center closed? Pop rivets are not good water sealers.

But I'm hoping a water hose test will give us a clue. I would put her out in the sun run water over the entire area for a good bit and then let the outside dry in the sun and then open it up and see if it will reveal the answer as to where?

Nice looking scooter and fast, it's RED!

JR

[john11v35]

If JR says soak the intake with water, you soak the intake with water.

Wouldn't you know it, but my neighbor walks by and asks what I'm doing? I tell him that I'm soaking the intake cause JR said to and you should always do what JR says. He looked at me and just slowly walked away.

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[john11v35]

Ok, so let's open her up and see what we've got. I keep the bike in the garage, so the water you see on the filter and pipe must have come from JR's soaking. Daggum it if he's always right!

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[john11v35]

But what about that mysterious rubber grommet, you ask? It appears as though it is a giant hole in my pipe above the filter which lets in bunches of unfiltered air and thus one would assume water as well. (WELL! get it? You get water from a well? Ah, never mind.)

I shone a penlight through the hole and took this pic from where the filter would normally attach to the intake. Look at all the pretty light! I'm gonna guess JR will say that is bad. So....Let's fix it! ;D

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[john11v35]

Look! I found a use for those surgery gloves that JR loves to wear!
(I didn't actually stuff that in the hole)

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[john11v35]

Since we are doing surgery, lots of Alcohol is needed. Unfortunetly, I was out of Coors light, but I feel somehow that it will do just as good.

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