Suzuki TS185 maintenance

**bogan** · 14th April 2013, 18:08

Originally Posted by Matariki

I'm not sure If I follow you. My TS isn't idling, so I'm not sure how to adjust it to where I can tell its at 2500 rpm. In terms or surging or bogging, it usually happens (sometimes) when I open up the throttle past half way and the TS hits 4000 rpm, it sticks at around 4000 - 6000 rpm.

I haven't adjusted the mixture screw (I don't know whether its called the Pilot air screw or the throttle valve sighting plug) either way, they're both on as tight as I could tighten them.

What the lowest speed you can get it to sit comfortably at with the throttle then?

Hmmm, if there is a mixture screw, it definetly shouldn't be as tight as it can go.

**Matariki** · 14th April 2013, 19:18

Originally Posted by bogan

What the lowest speed you can get it to sit comfortably at with the throttle then?

Hmmm, if there is a mixture screw, it definetly shouldn't be as tight as it can go.

I had another look through my manual and I found the following (which I don't fully understand):

Poor running at idle and low speed: Fuel/air mixture incorrect

Intake air leak - Check carburettor mountings and air cleaner hoses for security and signs of splitting. Ensure that carburettor top is tight and that the vacuum gauge take-off plug (where fitted) is tight.
Mixture strength incorrect - Adjust slow running mixture strength using pilot adjustment screw.
Carburettor synchronisation
Pilot jet or slow running circuit blocked - The carburettor should be removed and dismantled for thorough cleaning. Blow through all jets and air passages with compressed air to clear obstructions.
Air cleaner clogged or omitted - Clean or fit air cleaner element as necessary. Check also that the element and air filter cover are correctly seated.
Cold start mechanism in operation - Check that choke has not been left on inadvertently and the operation is correct. Where applicable check the operating cable free play.
Fuel level too high or too low - Check float height, adjusting the float tang if required.
Fuel tank air vent obstructed - Obstructions usually caused by dirt or water. Clean vent orifice.

I have checked 1,4,5,6,7 and 8. I'm not sure about 2 and 3.

"Adjustment of the cable is correct when there is a 0.5 - 1.0mm (0.02 - 0.04 in) of free movement in the cable outer when it is pulled out of its adjuster at the carburettor top."

I'm not sure how to measure the amount of free movement.

"When fitting the throttle stop and pilot air screws, ensure that each screw is first screwed fully in, until it seats lightly and then set to its previously noted position. Alternatively, set the pilot air screw to the setting given in the specifications section of this chapter (UK models only). The setting of the throttle stop screw will then have to be determined by following the adjustment procedure listed in section 9 of this chapter. With US models, take careful note of the information given in the following section."

I'm not sure what 'seats lightly' means (is the manual referring to 'finger tight'?). My TS is a UK Model. The manual in section 9 depicts a graph (Fig. 2.6 Carburettor mixture strength chart) with the following (hopefully this makes sense);

Throttle opening: 1/4 1/2 3/4 Full

Pilot air screw: Sits in the 1/4 section, with its tip (pointed part) overlapping slightly on the 1/2 section.
Jet needle: The bottom rounded part sits halfway in the 1/4 section, overlaps the 1/2 section and 3/4 section. The tip slightly overlaps the full section.
Main jet: The very edge of the tip (pointed part) overlaps the 1/2 section, overlaps the 3/4 section and the bottom rounded part overlaps half of the full section.

Again, not sure what this means.

"When the carburettor correctly refitted and with the engine running at its normal operating temperature, set the throttle stop screw to give the slowest possible idle speed. Turn the pilot air screw in by a fraction of a turn at a time until the engine begins to falter. Now back the screw off progressively whilst noting the number of turns required to reach the point where the engine starts to run erratically. The correct position for the pilot air screw is mid-way between the two extremes when it will be found that the engine is idling at its fastest. This should be close to the recommended setting. At this point, the engine should be idling at the recommended speed. If the reading on the tachometer (where fitted) indicates an idle speed which is slightly outside of the recommended, then the throttle stop screw should be turned until the indicated speed is correct."

Can somebody translate this to laymans (or laywomans) english? I'm confused...

"Always guard against the possibility of incorrect carburettor adjustment which will result in a weak mixture. Two-stroke engines are very susceptible to this type of fault, causing rapid overheating and often subsequent engine seizure. Changes in carburation leading to a weak mixture will occur if the air cleaner is removed or disconnected, or if the silencer is tampered with in anyway. Above all, do not add oil to the petrol, in the mistaken belief that it will aid lubrication. Adequate lubrication is provided by the throttle controlled oil pump."

What's the difference between a weak mixture and a rich mixture, and what is a normal mixture?

**bogan** · 14th April 2013, 19:42

That all sounds pretty standard, the translate this bit, is much the same as I suggested with the high idle mix adjustment.

Using the throttle, what is the lowest stable engine speed you can get it to run at?

**Matariki** · 14th April 2013, 19:55

Originally Posted by bogan

That all sounds pretty standard, the translate this bit, is much the same as I suggested with the high idle mix adjustment.

Using the throttle, what is the lowest stable engine speed you can get it to run at?

I would have to sit at my bike and check, but from memory, around 1500 - 2000rpm (thats with me keeping my hand slightly on the throttle). If I remove my hand altogether, the engine falters out.

**Matariki** · 14th April 2013, 20:24

I watched this video, I think I understand the relationship between both screws. First I need to adjust the idle screw to where the engine sits at 1300rpm (before faltering out). Then I need to adjust the mixture screw as according to the manual's recommendations. I hadn't realized that I had to do both sides of the carb.

http://www.youtube.com/watch?v=YxpQjDQzX7g

**Matariki** · 15th April 2013, 15:28

Hmm... now I have a new problem. My TS is idling at 3000rpm (with the coke on) and when I turn the throttle it surges up to 4000rpm and slowly creeps down to 3500rpm. I tried adjusting both the mixture screw and throttle screw (loosening them) but the TS isn't responding to either. The TS falters out when I turn off the choke. I hope I haven't screwed up the carb or the engine.

**Matariki** · 15th April 2013, 15:45

Does anyone here by any chance know what the idle screw and mixture screw settings are for the TS 185? My manual doesn't specify.

**bogan** · 15th April 2013, 16:36

If you have to run it with the choke on, it generally means the mixture is too lean, and you need to turn the mixture screw out. I've no idea what the TS setting are, but a common range is 1.5 to 2.5 turns out on many other bikes. So turn it in all the wy until you feel it bottom out (don't tighten it), then back out 2 full turns, then see if it will run without the choke.

**bogan** · 15th April 2013, 16:38

Originally Posted by Matariki

I would have to sit at my bike and check, but from memory, around 1500 - 2000rpm (thats with me keeping my hand slightly on the throttle). If I remove my hand altogether, the engine falters out.

Hmmm, it could be that the idle adjustment is damaged, so you may need hold the throttle steady at about 2000 to 2500 rpm when adjusting the mixture while running. Vice grips (over some rubber to protect the handgrip) the throttle against the brake level if you need to so as to ensure a constant throttle position for the tuning.

**ducatilover** · 15th April 2013, 16:44

Want me to come have a look at it tomorrow or Wednesday?

**Matariki** · 15th April 2013, 16:56

Originally Posted by ducatilover

Want me to come have a look at it tomorrow or Wednesday?

That would be great, what time or day would suit you best?

**FJRider** · 15th April 2013, 17:28

Originally Posted by Matariki

I haven't adjusted the mixture screw (I don't know whether its called the Pilot air screw or the throttle valve sighting plug) either way, they're both on as tight as I could tighten them.

Try just screwing the small brass bit (where the throttle cable enters the carb) anti-clockwise. This will lengthen the throttle cable outer and increase the revs by pulling on the cable inner.