Cat Code Plug again

[madman]

Grimmit are you still running with yours removed?
In my quest to eliminate the twistgrip vibrations I have decided that removing mine (cream coloured) might be a partial answer. I dont't remember the vibration when the cat was fitted and might try it without the plug, but am unsure of any side effects.

[oyster]

I was under the ipression that dealers pulled the cat plugs out to prevent fuelling nuiances? The Motronic defaults to a standard rich mix, similar with the O2 sensor disconnected; cat plug across the entire range, the O2 only at low throttle. The Motronic is quite basic, it is not clever enough to accept too many variations and merely defaults. Unlike cars, whose engine management systems were very clever even ten years ago. Their O2 read the whole throttle range and default to very rich.
I'll just add, I have become aware at max throttle my bike; no cat plug, no O2 sensor, full street Laser, full intake kit, IS VERY LEAN! So some time soon I will try the Laser chip.

[madman]

Mine came as new in July '04 with the gray plug fitted. I suspect that it runs quite lean as it blued the pipes very quickly, and is about 3 mpg more economical than Judes '02 single spark, which has not blued the pipes.
When I put the Y pieces on both bikes, mine developed the high frequency vibration in the right twistgrip. I had considered refitting the cat!
There are 8 different configurations with the cat code plug but I am not sure which will make the mixture a little richer across the range. I am not sure if I should try no plu or simulate the yellow plug by bridging the connections 30 and 87.
The gray plug bridges 30, 86 and 87.
The bike has no other modifications to the engine.

[r550s]

the motronic eprom can have several different maps put in it at manufacture; the coding plug (which is just a jumper) is just a convenient way of setting which map to use. It all depends what year/model motronic is on the particular bike, as to what maps were put in it, and what jumper configuration was used to select them. I'm told that there were variations. So, a particular coding plug e.g. yellow, might give a different spec map, if used with different motronics from different years. That might be why some models have a yellow plug, some a grey plug, and some no plug at all - they could well all be running the same spec map i.e. standard UK/ with cat/ 95 RON. It'd be nice if the motronics came with a 'leaner' map, or a 'richer top end' map, just so's the home tuner could twiddle, but I doubt it's that simple. I dunno of any real info about this stuff, and I believe that whereas 'pull the code plug if you remove the cat' (or similar) was quite possibly true for one model/year, I wouldn't assume it's a firm rule (the guys who didn't have a code plug to start with would struggle wouldn't they?). On the other hand, can somebody please shoot me down in flames with some reliable info?

[madman]

I understand the bit about the eprom having the different maps. A 2004 model with twin spark must have come from the factory with the same eprom as another model of the same spec and year. Somewhere the people who build the bikes must know which CCP to insert for which market.
I have a list of the different CCPs and the colour codes and even which pins that they connect, but what is missing is the info that the factory have on which CCP does what to a particular bike.
I would suspect that somewhere there is a list which says that bike a comes off the production line with a cat and gets a gray CCP and the next bike with no cat gets a yellow one or none at all.
Others must have been down this route before and I was hoping that I might find some info by trawling the web, but after 2 whole days doing so I can only find very general information. There must be tech sheets or build data out there somewhere.

[Steptoe]

Look here for cat code plug information http://www.ukgser.com/forums/showthread ... =code+plug

And don't buy a BMW cat code relay - it's just a jumper connection, as you can see in the pictures.

An expensive option for a 10 pence fix

[throttlemeister]

Bob,

A proper TBS can eliminate almost all vibration. Mine's chipped, with Staintunes and I just did a proper TBS. You wouldn't believe how nice it runs now. Very little vibration, so smooth, so linear. And very fast.

EDIT: Mine was way out of wack and I doubt the dealer ever checked it.

[nab 301]

Grimmit are you still running with yours removed?
In my quest to eliminate the twistgrip vibrations I have decided that removing mine (cream coloured) might be a partial answer. I dont't remember the vibration when the cat was fitted and might try it without the plug, but am unsure of any side effects.

As t meister says , maybe a TBS would sort it out , but from memory (your blog?) when you fitted your y piece you didn't use the support bracket, maybe this is an issue?
Nigel B

[madman]

To be honest I have done the valves, rocker end float and TBS about every 100 miles now to try and eliminate the vibration. The change to 5W50 oil helped a bit, but the TBS make little or no difference.
The removal of the mounting bar on the Y piece also helped a bit, but again not much.
I feel that I must try some different CCP options to see what that will do.
I do know that the actual box is only wires, mine had 30, 86 and 87 connected (gray box). If there is no improvement with the CCP pulled then I will make up some wires to simulate a yellow CCP, 30 & 87, to see if that helps.
I wish that I had kept the K1200GT now. But if I cannot get rid of the problem then I will get rid of the bike and go back to a four cylinder, shame as the 1100S is such a good looking and capable bike.

[r550s]

I don't know if the motronic is going to be behind your vibration problem: the injectors are fired as one, so they can't be 'off-balance', and the ignition advance (which is the only other relevant thing that it can alter) wouldn't really cause a tingling-frequency vibration. Hope you don't mind the obvious, but if the vibration arrived with an alteration to the exhaust system, try loosening all the joints (including the header/barrel studs & the link pipe), giving every bit a good wiggle to relax it, and then tighten it back up sequentially. Ideally, there shouldn't be any stress anywhere in the system. Just a couple of sentences to write it; but it could be half a days work to dismantle and clean and copaslip all the sections, to ensure that they are free enough to slide together and settle before you tighten all the clamps etc. That's not discounting any suggestions about throttle balancing etc. either.

[winger]

What do you use to balance the injectors,and how many miles has the bike done,how fresh are the plugs and what fuel are you useing.

[madman]

To balance the carbs, I use a Morgan cerbtune 2. I have used this on other BMWs including the R1150RT that I used to have with good success.
The bike has 9000 miles on it.
The plugs have been checked 3 or 4 times and never needed adjustment.
The fuel varies, sometimes I use 95 octane, which is correct for the bike, and at times I have tried 98 octane to see if it makes any difference.
I have also loosened all the front end bolts including the engine mountings and re torqued then, but to no avail.
Someone is going to say that it will cure itself when it gets to 20000 miles, but I will not put up with it for that long, if the CCP does not improve the situation then I will sell it and buy a four cylinder bike, BMW of course.
Thanks for all the input.

[winger]

A Morgan ain't good enough not matter how long you've been useing,better than nothing but thats all,no were accurate enough.

Mileage is barely high enough at 9000,mine still vibrated like a road drill at mileage.

The plugs!!!! kin'ell tell me you are jokeing, setting????,couple of thousand miles take e'm out,and chuck e'm in the bin,and thats either Bosch Platinum,NGK gold palladium,not you bog standard crap.

Fuel,i don't do 95 octane full stop,the motor doesn't like it and neither do i,mine still vibrates with cheap fuel in,even now.

Bottom line you've taken the cat off,it strangles the motor,how well do you work with hand over your mouth and you finger up your bum!!!!,thats why people fit SJ filters and open pipes and PC's,the problem being now the motor is able to work like it should and untill it's got some decent mileage on thats the way they are,mine was an absolute horror even with everything i did to it untill the motor broke 10,000 miles,and on hot or warm days i'll wheel my tiger out cuz it can handle that kind of weather better,but you've been on the board some time so i guess you know all this anyway.

[throttlemeister]

Just to recap...

You did 9000 miles without problems, then fitted a Y piece and the problems start. And if you can't fix the problems without removing the Y piece, you're gonna sell.



Obvious solution is to put the cat back as it ran fine then and you did quite some happy miles on your S.

Seems to me though you are not nessesarely looking for a solution, but an excuse to buy something else.

[Boxadog 2000]

Like they said 10k s is so different from a 20k s.

However I would also be looking at the final drive, check the usual para lever bearings and also the diff.

Bob

Or buy a GS and enjoy, you then dont give a shit as it's just a hoot to ride.