Bike Smoking when coming off revs, Rider behind said smells very rich after new

[T250]

Might be nothing, but do you leave the bike on the side stand? I've had several bikes over the years, including my 14, if left on the side stand over a period of time it causes the near side to smoke on start up.

[Xdiavel]

I'd go with swapping those two seals Seth mentioned before you consider spending hundreds of quid on it.

Well guys I have ordered the parts so will see where this will take me. Even just to do this little job has cost over £80 so fingers crossed. Only thing that makes me think it may not be is like the stem seals , I would imagine it would be bad on start up if they weeped etc.

Time will tell and at least they will be done.

Ouch, that's a new cam cover gasket & so forth too then? I don't think I've ever replaced one, I just smear with a tiny bit of sealant & forget it afterwards. Personally I'd do the same with the PAIRs seals, but then I'm a cheapskate & reuse seals when rebuilding brakes or slave cylinders too.

Hopefully it fixes your issues and as Seth says, check the valve clearances while in there. They'll be fine, I've never known one of these bikes needing them adjusting unless they've had new cams fitted. But it's easy to do so worth it for peace of mind.

Yeah afraid so    new Rocker Gasket £48 rocker bolt washers £31 for 8 little bits of rubber ffs and the 4 pairs seals. As it's 20+ yrs old I would imagine the old ones will be pretty rough. Valves should be fine as only done 8k miles and sounds sweet.

I never thought an old Suzuki would cost more to repair than my Ducati, I changed the rocker cover gasket on that and cost half as much lol

[Xdiavel]

Might be nothing, but do you leave the bike on the side stand? I've had several bikes over the years, including my 14, if left on the side stand over a period of time it causes the near side to smoke on start up.

Good shout, But sadly this is either on centre stand or side and even after a 2 hr blast. As seen in the youtube video link, That was on the centre stand and fully hot. Doesn't smoke at all when cold.

[Hooli]

I'd go with swapping those two seals Seth mentioned before you consider spending hundreds of quid on it.

Well guys I have ordered the parts so will see where this will take me. Even just to do this little job has cost over £80 so fingers crossed. Only thing that makes me think it may not be is like the stem seals , I would imagine it would be bad on start up if they weeped etc.

Time will tell and at least they will be done.

Ouch, that's a new cam cover gasket & so forth too then? I don't think I've ever replaced one, I just smear with a tiny bit of sealant & forget it afterwards. Personally I'd do the same with the PAIRs seals, but then I'm a cheapskate & reuse seals when rebuilding brakes or slave cylinders too.

Hopefully it fixes your issues and as Seth says, check the valve clearances while in there. They'll be fine, I've never known one of these bikes needing them adjusting unless they've had new cams fitted. But it's easy to do so worth it for peace of mind.

Yeah afraid so    new Rocker Gasket £48 rocker bolt washers £31 for 8 little bits of rubber ffs and the 4 pairs seals. As it's 20+ yrs old I would imagine the old ones will be pretty rough. Valves should be fine as only done 8k miles and sounds sweet.

I never thought an old Suzuki would cost more to repair than my Ducati, I changed the rocker cover gasket on that and cost half as much lol

When you do it, careful of those eight bolts holding the cam cover on. They are easy to strip the holes in the cam carriers they bolt into. I double check they are clean before starting them in the thread.

From memory they are M7x1.0 which I found out after having to put thread inserts in three of mine.

[Xdiavel]

Hi,

Well the update so far, took it for a good blast yesterday and rides beautifully. Pulls all the way to redline etc  stopped several times and checked for smoke and there was none.
Let the bike sit idling for some time and actually see the fan come on lol thought it was a fake 😅

After idling for some time and revving, the smoke started to return. I smelt it and smelt very fuel rich.

Today I thought I would check the sensors. EOT sensor I couldn't really check as had the tank off etc so couldn't run the bike to check oil temp. Air temp sensor was working fine. I checked the tps and was reading 1400 ohms and not 1100. I take it this would also make it run slightly rich if it thinks the valves are more open than they are? The stps was also reading 1000 ohms and not 800.

I could not adjust just yet as do not have the right tool.

What's people's take on this?

Cheers

[seth]

Setting the tps &stpa are always a good thing .
I'd still also go with my first thoughts of a leaking pairs seal as the smoke comes when the motor is hot(oil thinner) or a valve stem seal I'd still pop off the pairs covers and have a look in (remover the reed valve holders) as it's a quick way to see if the problem is there (any wetness or oil shouldn't be in there)
Good luck 

[Xdiavel]

Setting the tps &stpa are always a good thing .
I'd still also go with my first thoughts of a leaking pairs seal as the smoke comes when the motor is hot(oil thinner) or a valve stem seal I'd still pop off the pairs covers and have a look in (remover the reed valve holders) as it's a quick way to see if the problem is there (any wetness or oil shouldn't be in there)
Good luck 

Will do, will I need pairs gaskets as well mate?

[Eric GSX1400K3]

Shouldnt need new gaskets for the PAIRS covers.

Blue smoke is oil, so you have oil leaking into a hot exhaust somewhere. 

Good tip on the PAIRS reed valves.   Is your PAIRS still connected, or has it been blanked off like most do? Id be checking the seala from them down to the exhaust, as Hooli said, these motors rarely need valve clearances checked and or valve stem seals done.

If you have a multimeter to check the TPS and STPS, all you need to adjust is the correct Torx to undo the screws that hold them in. Check out the manual for setting the TPS, pretty easy, just need to make sure idle is set at 1100rpm, then set the TPS to 1100 Ohm to match by adjusting the sensor position relative to its mount. The eyelets  in the sensor are slotted to suit.

The upper value doesnt matter too much, its the at-idle value thats important

[Hooli]

One other comment on setting the TPS. Balance the throttles first, as that affects the reading because the sensor is using no1 TB to know the position of no3 TB (which is the one the cables are connected too).

[Xdiavel]

One other comment on setting the TPS. Balance the throttles first, as that affects the reading because the sensor is using no1 TB to know the position of no3 TB (which is the one the cables are connected too).

Hi,

Thanks for the info, I have balanced the throttle bodies a month ago and got all the parts to carry out the pairs seal replacement. (Hopefully easy to find once cover is off)

The sensors are both out a bit and idle is at 1100 so once to security hex turns up I will adjust those to spec. :-)

*edit the pairs system is still connected

[Hooli]

Ahh you should be fine then.

I always mention it as I've known people do it the wrong way round & end up with a bike running worse than they started with.

[Eric GSX1400K3]

A tip then if PAIRS is still hooked up is to remove the diaphragm valve (under the tank) and hoses to the PAIRS valves and blank off the outlet from each PAIRS valve on the rocker cover. I just used a short bit of rubber vac hose zip tied onto the PAIRS cover outlet, doubled back on itself and the end crimped by a zip tie. A blanking kit makes it look better but does the same. The tank hides the covers mostly.


Theres a sticky on here detailing more on deleting the PAIRS.

Once youve disconnected PAIRS, check for smoke from the exhaust, if still there then its the PAIRS seals through the head, valve stem seals or piston rings (in descending order of likelihood).

You also mentioned a rich fuel smell, I reckon thats related to the TPS setting and unrelated to the (blue) smoke issue. Correcting the tps will make the throttle smoother and improve fuel economy in my view

[Xdiavel]

One more questions guys,

Is there anything I should be aware of when removing the rocker cover? ie pipes, gaskets anything under it that may come loose etc? Thanks

[seth]

Nope just taken it easy with the rocker gasket and reseal the half moons when refitting it .
I replied to your pm and sent an email to you .
 

[Xdiavel]

Nope just taken it easy with the rocker gasket and reseal the half moons when refitting it .
I replied to your pm and sent an email to you .
 

Seen that Seth, Much appreciated