SAS, 200 4t

[buzzies]

Has anyone blanked off their sas, I assume its there to comply with eu emitions laws. How does this system work? I have had a good look at mine and it appears that it is controlled by a vacuum pipe from the inlet manifold. My guess is that exhaust gasses are passed back through into the air box for reburning. But contary to that, I have removed the valve and by sucking and blowing through the pipes, it appears that air can only pass in one direction towards the engine when the inlet manifold pipe is sucking ie reving. Judging by the soot and carbon on the metal pipe I assume its connected to the exhaust system within the cylinder head. I cant get my head around this one, If it was a egr system then it seems to be working arse about face. Any help please

[0003MUD]

You seem to have investigated in a bit more than me!

The issue with mine was that it was assumed the EGR valve had failed open so hot exhaust gases were coming the wrong way through the valve.

It was explained to me by Barrus that when the throttle is closed the EGR valve opens and air is sucked into the engine to mix with the exhaust gases effectively watering them down so the exhaust fumes being expelled meet the euro immersions criteria. It may be that they are recirculated and burnt again I'm not sure.

I do know that on a Land Rover the EGR is simply removed and blanked off before the engine is remapped. Not sure if the same applies to the 4t or what impact it would have, but my interpretation is that it is only to meet EU requirements and so could potentially be removed without it affecting the MOT but check with someone who knows more than me before doing it.

Cheers


Mark

[buzzies]

Thanks for your reply Mark, I run a disco 300tdi and that has the egr blanked off, its a great mod to do . With the sas pipe on my LML I'm not too keen on the heat that the pipe seems to get going to the valve. In a nutshell and between you and me I've blanked off the pipe at the cylinder head end. Just like a 300tdi. My scoot runs crisper and sharper with it blanked. PS you cant see the blanking plate so hopefully my warrenty still stands or its a two min job to remove at the road side. According to the LML 200 4t service manual the pipe needs cleaning out. My pipe was starting to fill with carbon. According to Barrus air is 'sucked' into the engine to mix with the exhaust gasses, whilst on the exhaust stroke of the 4 stroke cycle I pressume. Exhaust stroke blows not sucks . So if its drawing air from the filter through the valve I cant see why it needs cleaning. I will keep you posted on it progress Mark. Well done on your great result with Barrus ......also hats off to Barrus for sorting a happy ending.

PS. I have also removed the inner filter in the air box and left the outer one insitu. When you compare the filters of a PX or a direct bolt onto the carb filter, the 2004t filter is like a ruddy bath sponge any thicker and I'm sure the engine would implode lol. thanks John

[tipper]

Any speed improvements with these mods buzzies ?

[buzzies]

Not been on a blast yet. Around town and a short 50mph stint it is crisper and got to 50mph a lot smoother and quicker. I'm off to Bowness this Sunday so I will report back. I'm still running in but before blanking it sat at 60mph on the motorway and still had a little throttle to go.

[Chipper]

I've removed the sas completely and blanked all the pipes, and also that inner air filter is long gone, it's only there for dusty Indian type conditions!! The scoot definitely feels more responsive, I havnt had chance to open her up yet because she's in bits being modded. As soon as I get her out I'll let you know.
Disco 300tdi owner with blanked EGR and decat

[buzzies]

A little update........my scoot ran like a dream. It throbbed along merrily at cruising speed of 58mph at 1/2 throttle. A further twist of the throttle saw it grunt crisply up to 65mp. Its not that I want 80mph or more........its just that I want to sit on the motorway at 60 mph all day long, up hill and down dale without hovering my fingers over the clutch. We rode north up the left hand side of Bowness lake, it is a twisty winding road and my scoot responded brilliantly. Riding a 200 4t reminds me of previous motorbikes I have had. It closely resembles the characteristics of a bmw r80t. The grunt and feel of the throttle is the same but scaled down. You learn to 'roll' the throttle on and off. The 200 needs to be 'pushed' into taking corners, it tries to stand upright and you need to get your knee down. Gear changing is a lot more often than on a 2t. Approaching a bend, choose your line then drop down a gear, around the apex and then power out of it with a powerfull manly grunt.

[sidetrial]

Hello , now my 200 is running sweetily , fuel starvation solved , I'm planning to remove the sas completely , how did you blank off the different intakes (cylinde head, carb, air filter)?

[buzzies]

I have made a blanking plate that 'sandwiches' between the metal sas pipe and the cylinder head. It is almost impossible to spot the alteration. I had to grind the short shoulder off the metal pipe end to make it sit flat. When you remove the metal pipe you will see what I mean, its like a stub that passes through the gasket. Looking at my scoot engine it appears totally standard, I didnt want any insurance problems incase of an accident claim. If my scoot is carted off by a recovery truck and I'm laid in hospital, I dont want the stress and worry about it being altered from standard. Also it is still under warrenty so I dont want the hassle of refitting all the associated pipes/tubes/valve etc when it goes in for service. As it stands at the moment all I have to do is remove two bolts and 'slip' the plate out, then refit the two bolts. If in time I remove all the sas gummings and filter, I will opt for a filter sock to fit directly onto the carb. The vacuum pipe on the carb will be blocked by a stubby length of tube with a plug/bung in it.

[tipper]

Sounds like a lot of hassle, would you say its worth it ?

[buzzies]

It does sound a lot of hassle but if your are just blanking the sas then its a 15min job to drill, shape and fit a blanking plate. Benefit wise, my scoot is crisper and runs better with it done, I also dont fancy heated petrol tank. I suppose blanking the sas is in the same boat as decating or removing filters from a 2t. The daft thing is that if LML was to bin the original air filter box and the SAS junk, there would be enough room to double the size of the fuel tank. The only down side would be the need to fit a fuel pump as the carb would be higher than the fuel cock/tap. Oh and I suppose the upside to this would be no more fuel starvation problems.
Hmmm.........sounds good.......I wonder when someone will market this idea. "Long range fuel tank/pump with fast flow tap fitted.

[tipper]

Sounds like a good idea,it would be useful to have a bigger tank.

A guy on here called Dixie removed the air box from his 4t and tried to fit a px tank which would have given him a range of around 400 miles I think he said but there wasn't quite enough room for it to fit in the frame.

[Saxon]

Hi ,
Could you post some pictures and instruction on how to do this mod? It sounds like a good idea so I might have a go if I know what i'm looking at. Like some have said it should run better and faster for the engine size and 4 stroke.

[buzzies]

Will do Saxon.........give me a couple of days to put it together

[POS]

Good show buzzies. I'm very tempted by this if it's not too difficult.

[Saxon]

Hi buzzies,
Nice reply thanks we all read the posts but some times dont want to sound daft because we dont always understand some of the stuff discussed. So I will look forward to seeing "the how to".
All the best.
saxon

[kingjim92]

Hello again i did this on my 125 if its the pipe coming from the exhaust, apparently when this pipe is blocked off the scoot runs crisper as with landrovers and the such because the air that is taken in is obviously cooler and therefor denser, as air becomes less dense when hot the scooter doesnt burn the fuel/ air mixture as efficiently as it does when running cooler, sorry if this doesnt make sense but im thinking off the top of my head whilst doing a 12 hour shift and on the plus side the scoots not taking in the carbon?

[mickyboy73]

Is it not easier to just disconnect the old air filter and SAS system completely and fit the bolt onto the carb filter that Phil is using on he's 4T ? Or am I missing something ?

[kingjim92]

I suppose your right mickyboy, it may be easier to just upjet and put on another filter but i spose blanking it.off may just be a peace of mind for service/warranty and mot purposes ive got a pod filterfor my 125 4t but i just need to get some jets so i can put it all together. I dont know really anything about these scoots but im learning from the forum and things ive heard.

[dimitris883]

Can anyone upload a photo of this modification?(removable Sas)