Suzuki Step 125 - Loose Power After 10 Kilometer Or More

[vel_tins]

Hi,

I have a little problem with my Suzuki 125 Step (15.000 Km on the clock).

Normally I only go small distances (3-5) Kilometer and everything works fine.

But today I took the bike for a longer ride about 20 KM. After around 8-10 Kilometer the Bike

lost Power and after more 5 Kilometer, the maximum speed went down to 40-50 Km/h.

After a hour or more, I started the bike to go back, first 10 KM ok, then the same before.

Maybe Transmission or Ignition?

I think it is not an engine Problem, because the bike starts always fine and no strange sounds

Any ideas are welcome

thanks

[visions]

Classic symtems of the tank air breather blocked.

Check the air breather into the tank. Its more than likely partially blocked and not allowing sufficient air into the tank to make up for the fuel used.

It creates a partial vacuum in the tank that the fuel pump cannot overcome. Means the engine is starving for fuel...equals loss of power. You will also do damage to pistons and valves

if you continue running like that...if that is indeed the problem.

[Scottish Thailander]

Overheating?

Checked it has enough engine oil?

On a short trip you may not notice as the engine warms up, but as the engine gets hotter the pistons will heat up and expand and you will notice a slow down - if you are lucky. Go much further or longer and the engine will heat up so much that you may not be so lucky and it will seize, break a piston ring, or worse. Check the oil level!

Other than that, there are many possibilities, brakes overheating, loss of compression, etc., which I will leave to our more mechanically practiced members to expand on.

.

[robblok]

Overheating?

Checked it has enough engine oil?

On a short trip you may not notice as the engine warms up, but as the engine gets hotter the pistons will heat up and expand and you will notice a slow down - if you are lucky. Go much further or longer and the engine will heat up so much that you may not be so lucky and it will seize, break a piston ring, or worse. Check the oil level!

Other than that, there are many possibilities, brakes overheating, loss of compression, etc., which I will leave to our more mechanically practiced members to expand on.

.

I had that happening to my bike when the watercooling broke down. I was lucky there was no damage but slowing down was obviously enough. The red warning light never came on.

[Tigersachsclub]

Classic symtems of the tank air breather blocked.

Check the air breather into the tank. Its more than likely partially blocked and not allowing sufficient air into the tank to make up for the fuel used.

It creates a partial vacuum in the tank that the fuel pump cannot overcome. Means the engine is starving for fuel...equals loss of power. You will also do damage to pistons and valves

if you continue running like that...if that is indeed the problem.

This is the same i would have suggested(tank air breather blocked). Not a big problem and easily fixed. But it needs to be done before it makes damages.to your bike.

Tiger/Sachs Club - Mbox

[vel_tins]

First, thanks for your suggestions

This is the same i would have suggested(tank air breather blocked). Not a big problem and easily fixed. But it needs to be done before it makes damages.to your bike

Yes, this sounds logical to me, because the bike has not been moved long time.

Easy to check, I can open the filler cap and try out....

I will test it tomorrow and let you know

Engine Oil has been changed some days before.

Engine is aircooled, so I think no overheat.

Edited May 26, 2010 by vel_tins

[Scottish Thailander]

First, thanks for your suggestions

Engine Oil has been changed some days before.

First, you are welcome.

Second, if this started after the oil change then just check that they did remember to actually put new oil in. It is not unknown that this simple task has occasionally been forgotten by the mechanics!

.

[neverdie]

When the OP return, if his problem has persisted after the tank air breather, I have another idea, but it requires a long description, so I will wait to see if the breather fixed the problem first.

[vel_tins]

no time yesterday.

I will try to check it out today. I think

the roads beside the railway tracks can be used for testing :-)

[vel_tins]

Well, it is NOT the Tank Air Breather...

I tried today and after some kilometres with a speed around 90-100 km/h,

the speed went down to 40 km/h.

But this is not a slow process, it seems that it happens nearly from one moment to another.

Let me say around 10 seconds, from 90km/h, then I had to brake , after this - no power

Then I stopped the engine for about 15 minutes, then start again and everything was ok.

Any more suggestions?

Edited May 29, 2010 by vel_tins

[Tigersachsclub]

Well, it is NOT the Tank Air Breather...

I tried today and after some kilometres with a speed around 90-100 km/h,

the speed went down to 40 km/h.

But this is not a slow process, it seems that it happens nearly from one moment to another.

Let me say around 10 seconds, from 90km/h, then I had to brake , after this - no power

Then I stopped the engine for about 15 minutes, then start again and everything was ok.

Any more suggestions?

I still believe that it could be a fuel supply/flow issue from tank onwards...perhaps the fuelfilter or the fuelpipe is blocked by something?

Tiger/Sachs Club - Mbox

[neverdie]

Well, it is NOT the Tank Air Breather...

I tried today and after some kilometres with a speed around 90-100 km/h,

the speed went down to 40 km/h.

But this is not a slow process, it seems that it happens nearly from one moment to another.

Let me say around 10 seconds, from 90km/h, then I had to brake , after this - no power

Then I stopped the engine for about 15 minutes, then start again and everything was ok.

Any more suggestions?

Yes, I have a suggestion, please bare with me and I will try to explain.

I recently had a problem with my Suzuki Raider. Like you I was riding along one moment and everything was fine and the next minute I had considerably less power and the bike would accelerate very reluctantly from 1000rpm to 5,500rpm but wouldnt accelearte past that point in any gear. Top speed was down to 70 something km/h & you needed about 2km of straight road to get to that speed .

After a quick stop and check of everything (twice), I continued on my dangerous journey floundering in the traffic until I got to the inlaws. During that 25km ride I decided it must be an electrical problem. After I got going again the problem persisted until I reached town where I stopped and refuled. Upon starting off from there I was instantly able to continue with full power for about 1km before the restriction returned .

At the inlaws I ran through everything I understood, right down to checking spark, fuel flow etc. At the end of all that I thought to myself this can only leave a problem with the bikes CDI. Onwards and upwards, I checked the power supply (Battery & the reserve power levels were below 10volts). I checked the system was charging before heading to the Battery place. On the way I stopped and had a friendly chat with a mechanic I know at Suzuki. I asked him if it was possible for a faulty battery to effect the CDI. His reply, "Absolutely".

@ the battery joint I got my hands on the best sealed battery I could purchase (400baht). I put it in the bike and PRESTO, Problem fixed.

What you are describing almost sounds similar to me. I would check the battery, even if somehow it seems to be starting the bike okay, there may be a problem with the internal cells of the battery that are causing this, I'm not battery engineer thats for sure.

[Tigersachsclub]

Yes, I have a suggestion, please bare with me and I will try to explain.

I recently had a problem with my Suzuki Raider. Like you I was riding along one moment and everything was fine and the next minute I had considerably less power and the bike would accelerate very reluctantly from 1000rpm to 5,500rpm but wouldnt accelearte past that point in any gear. Top speed was down to 70 something km/h & you needed about 2km of straight road to get to that speed .

After a quick stop and check of everything (twice), I continued on my dangerous journey floundering in the traffic until I got to the inlaws. During that 25km ride I decided it must be an electrical problem. After I got going again the problem persisted until I reached town where I stopped and refuled. Upon starting off from there I was instantly able to continue with full power for about 1km before the restriction returned .

At the inlaws I ran through everything I understood, right down to checking spark, fuel flow etc. At the end of all that I thought to myself this can only leave a problem with the bikes CDI. Onwards and upwards, I checked the power supply (Battery & the reserve power levels were below 10volts). I checked the system was charging before heading to the Battery place. On the way I stopped and had a friendly chat with a mechanic I know at Suzuki. I asked him if it was possible for a faulty battery to effect the CDI. His reply, "Absolutely".

@ the battery joint I got my hands on the best sealed battery I could purchase (400baht). I put it in the bike and PRESTO, Problem fixed.

What you are describing almost sounds similar to me. I would check the battery, even if somehow it seems to be starting the bike okay, there may be a problem with the internal cells of the battery that are causing this, I'm not battery engineer thats for sure.

Very interesting post and makes sense also, lets hope it solves vel_tins problem on his bike too...

happy trails,

Tiger/Sachs Club - Mbox

[DickDastardly]

Did you find the problem?

[vel_tins]

Did you find the problem?

well, after a long time not careing about the bike (only GF rode it to the next 7/11 ), now I decided to fix the problem...

Today I checked Battery = 12V, checked alternator = 14V.

Two days before, when the problem occured again, I noticed stronger Vibrations, seemed to be caused by transmission(?). I stopped the bike, waited a little bit and started again. Full Power for the next 5-6 Kilometres.

I am absolutely clueless. Maybe broken CDI?

Or is it possible that inside the transmission is some "blocking" (Vibrations described above) which causes something like a "brake-effekt", so that the bike cannot accelerate?

PS: I want the change the transmission Oil. What Oil do I need? ATM or Engine Oil?

Edited February 2, 2011 by vel_tins

[dickyknee]

Check your oil level. Too full maybe?

[vel_tins]

Oil Level is ok, I have checked it today...

what the hell is wrong with this ***** bike ...help...help

Edited February 2, 2011 by vel_tins

[Lickey]

Veltins, try checking the choke operation, it might be off at the handlebars but not the carb, when the problem appears, make sure the choke is off, then wiggle the cable at the carb, start engine and see what responce you get at speed,

Good Luck..

[VocalNeal]

Like Tigersachs says it sounds like the fuel filter is blocked or partially blocked.

How are the brakes? Could the rear brake be seized partially on?

Edit: Just noticed this

then I had to brake , after this - no power

Then I stopped the engine for about 15 minutes, then start again and everything was ok.

Edited February 4, 2011 by VocalNeal

[vel_tins]

Like Tigersachs says it sounds like the fuel filter is blocked or partially blocked

Yes, this seems to be most logical reason, and was my first idea too.

But this bike has no separate filter, I think it is integrated into the fuel cock. (view image)

Today I will remove the fuel cock and check.

Edited February 4, 2011 by vel_tins

[VocalNeal]

Like Tigersachs says it sounds like the fuel filter is blocked or partially blocked

Yes, this seems to be most logical reason, and was my first idea too.

But this bike has no separate filter, I think it is integrated into the fuel cock. (view image)

Today I will remove the fuel cock and check.

That type of filter is unlikely to block unless you had some serious gunk in the tank. But I have been wrong before.

Does it sound feel like the engine is failing to rev up or the bike is not willing to move even though the engine seems willing.