Reed Valve..?

Question

Does a 1980 Suzuki TS 2-stroke need a reed valve, It is on the underside of the barrell?

I had the bike in bits and there was one in the box and i bolted it on, but in the manual there is no mention of one at all.

Could this stop it from starting as currently it wont start and i wanted to have a good idea before i started disassembling it?

Thanks.

Answer 1

LOOK TA THE SHOP MANUEL IF IT SAYS PISTON PORT THAN IT WILL NOT HAVE REEDS CAUSE THE PISTON ALSO ACTS AS IT OWN REED

Answer 2

First, a couple of comments.

1. Damon A - you ain't got a clue.
2. Always give displacement as well as year, make and version (ie TS) when you answer a question.

Yes, the TS should have a reed valve, and from the parts diagram for a TS185, it is on the bottom of the cylinder. If it does not seal, it will let the air/fuel mix blow back through the carb as the piston goes up. on compression. The cycle is this - you kick the engine, we start with piston at top. As piston comes down, 1st cycle, no much happens, as piston rises, a reduction of pressure in the crankcase occurs, pulling mixture through the carb, and reed valve. Piston goes over top, starts down, this compresses mix in crankcase. Ex port opens, then transfer ports, and the compressed mix in c-case goes into cylinder. Piston continues to bottom, then to top, where all ports are closed by about half way up, and mixture is compressed. Just before top, spark occurs, mix burns (very fast), and this heats air, pushes piston down again. Ex port opens, (Half way down), ex gas exits, bit lower, transfer ports open again, as the piston allowed the c-case to refill with fresh mix as it went to the top, As piston continues to bottom, cylinder is refilled with fresh mix, and the cycle repeats.

So, as you see, the important steps are:
1. Reed valves seal tightly as piston goes up.
2. Piston ring seal is good, piston is proper fit in cylinder. Check compression, should be 100 psi, or more.
3. Spark occurs at right time. (On some 2-strokes, with point type ignition, there was a cam which was behind the flywheel, and opened the points. If this cam was on wrong way around, you would not get a spark). I do not know if you bike is this way or not, but just something I found one time. Make SURE you have a good clean spark plug, and it fires when engine is
cranked over.
4. Make sure carb is assembled correctly. Some carbs, the slide can be put in 180 deg.out, ie the cut-away on slide toward engine. This will not start.
5. Exhaust pipe plugged? Hope not..
6. You said the bike was in bits, are the main bearings, and the main seals good. If not - no go. Normally, some reason if they are in bits (Are you in England?)

This is a quick run down. If you have questions, you may E-mail me, with them, see if I can help.

Tomcotexas

[e-mail]

Answer 3

Two strokes typically use the reed valve as an intake valve.

Fuel oil mixture is drawn through the carb and into the crankcase, where it lubricates everything on the bottom end of the engine. As the piston comes down, it forces the mixture from the crankcase through the reed valve into the cylinder, pushing the exhaust gasses out the exhaust port.

As the piston rises, it closes the exhaust port, and the pressure of the compression in the cylinder force the reed valve closed.

Without the reed valve, you might not get any compression at all. Or with it installed backward, you won't get any fuel to the cylinder; no fuel means it won't run.

Look exploded diagram and it should show you how to put the valve in. In the event that it doesn't, look at the valve. It's a wedge shaped thing, and the tip of the wedge should point towards the cylinder.

It could also be gunked up and not closing, which would also cause a loss of compression, even if installed properly.

Just a couple of guesses.

Answer 4

Listen to Tomcotex.. a man who knows what he is talking about.
He is right Damon is talking pants which is a bit worrying when he says that two strokes are very simple and then decribes the role of the valve incorrectly.
Darren - technically not all two strokes have reed valves. Racing Aprillias for example use disc valves run off the end of the crank shaft.

Answer 5

Yes Shuggie, that is rotary valve induction.

You do not have a reed valve when your engine is piston valve induction, where the piston itself is the opening and closing valve.

Reed valves work like a check valve, it opens from vacuum, and closes under pressure. If you have a reed valve engine, it will not run without it.

Answer 6

Always give year, make, "engine size" and model # when asking questions. We need all of that info to give an informed answer.
The TS came in 4 sizes.
http://www.bikebandit.com/parts
Go to - your bike - Engine & Exhaust - Cylinder

Answer 7

yes you need a reed valve. all 2-strokes require them as they controll fuel,air and oil without them your bike just wont start.