8 replies to this topic

[Jeboslav]

Hi to all,

 

I have a TDM 850 3VD 95. I bought it about 2 years ago. It has been running relatively fine all up to the time I put the bike in winter storage. I had problems with around 3000 rpm. Sudden shaking and loss of power. If I skip slow transition and "jump" to 4000 rpm the problem is unnoticeable.

 

When I plled the bike this spring I did some maintanace. I removed the fileter and left it to soak in water and detergent. When removing the filetr I found out that the carburetor boot is too stiff and has slipped from the carburetor (both). Dont really know how longI was trfining like that.

 

I also used "Wynn's Air intake & Carburettor cleaner". As instructed I let the bike warm up and intermediately spray in the left and right carburetor. After this I filed up and went for a ride. After 10 km suddenly the motorcycle stared to run extremely bad. It would shut down, stutter, back fire, and was very loud... I barely made it home. I had to keep the rpm really high to run. If it drops the engine stops.

 

When I got home I bought new spark plugs. The old ones were totally powdery and black (but not oily). I also saw that I had a big hole in my exhaust - that explains the sound. I found an electric arc welder and closed the hole (This was a pain to do. Since this is my first welding experience. Took a few days). I could ride it like this for the next 50 km, then the same problem. Opened the plugs and they are totally black covered with fine powder again. I repeated this cleaning and riding, a couple of times.

 

I took the bike to the mechanic he said that the compression is good so it should be carburetor problem. He told me that the jet needles need to be changed. For the whole thing would cost 600 euros. Too rich for me. I ordered form Kedo needle jets and jet needles and replaced them. When I got the parts I saw that the needles are shorter and thicker. Kedo assured me that that is my part and my parts are unknown. You can see from the pictures. I cleaned the carburetor with the carb cleaner spray and canned air. I didn't remove all needles and jets though. When I assembled the bike and tested it, but I still have the same problem.

 

I really like the bike, long before I bought it. But I am not sure my skill are good enough to keep it running. All help is greatly appreciated.

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[SingleCylinder]

Are the plastic choke plungers worn? That can cause the rich running.

[Jeboslav]

I will take a part the carb thees week. I hope its the plunger. If its not the float height flooding the engine, or some strange reason suddenly the pilot jet started to pour way too much fuel, I am out of ideas. The problem came on suddenly .

[Bjørge]

If it's the usual worn emulsion tubes it wouldn't suddenly run so bad it stops. The question could be, of course, what condition the carburetter was in when you bought it? Did you ever see the grayish color in the can "exits" ? If it was already running rich, maybe....

[Jeboslav]

When I bought the bike, I think it was running a bit lean. It would get very hot relatively fast. Few millimeters from the red zone. Than the cooler kicks in and it goes down. The last months before I put the bike in storage I got less and less millage. This could be my emulsion tubes getting more worn and running more rich or it could be just me driving faster. 

 

I suspect that using the "Wynn's Air intake & Carburettor cleaner" may have done something. As all of these problems suddenly appeared 20 minutes after spraying. When I opened the carburetor I found out that it was very clean. Only the rubber gasket (or whats its name) around the bowl needed a bit of cleaning. Also one of the rings on the float chamber looked a bit worn.But It looked as it was still doing its thing.

 

I don't understand the question "Did you ever see the grayish color  in the can "exits" ?

Edited by Jeboslav, 08 August 2017 - 09:05 am.

[Jeboslav]

I have the results. I measured the float height for the carburetors. Here are the pictures:

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To make sure the camera angle is not giving a wrong reading, I made marking with a pencil like so:

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I hope I made the measurement correctly. I was holding the motorcycle leveled (I don't have a center stand) while my wife helped me make the pencil marks. I tried to move the hose up and down until I was sure this is the level the fluid wants to settle.

 

After this I removed the carburetor and checked the choke. Here are the pictures:

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Does this mean that the choke is good or bad. The spring works well as I can see.

 

 

[Studley Ramrod]

Everything looks ok in the photos.

[Jeboslav]

Shouldn't the level be on the line? Its almost a centimeter above.

I measured the air/fuel mixture screws. Left is 4 and one quarter turns out and right is 3 and 3 quarter out. Last quotes are not that precisely measured. This should make it really really lean. I dont get it.

 

I opened the air cut-off valve and it doesn't look well. Here is a picture:

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I know it should regulate backfire on deceleration but I don't know if this condition would cause the super rich condition.

[Studley Ramrod]

Pilot screws can vary and 4 turns out isn't really surprising.

No, the level shouldn't be on the line. It should be 7.4mm to 8.4mm above the line. 

 

Best thing to do is to put needle clip position, pilot screw settings and fuel levels back to standard setting and then adjust pilots and balance the carbs as required.  Ideally you would also replace all gaskets and O'rings before you do this.

 

Also, if the bike is running rich it might be worth checking the air filter is clean and dry after you washed it.