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1Back to top Go down    cant lower the idle revs on Thu Apr 02, 2015 6:47 am

mr lee esq

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Hi there, does anyone have any advice or can point me in the right direction as to how I can lower the idle revs on my 1984 K100 rt thats done 26,000 miles?
I bought it as a non runner got it going and mot'd, but its always ran rough.I've replaced plugs leads air and fuel filters and reshimmed the valves as 4 exhaust and no4 inlet valves had next to no clearance. It ran alot better since but revs too high ( 1500- 1750) on tickover. We balanced the throttle bodies as explained on one of the threads on the forum, but cant get it no lower even if the TPS is moved. Also it threw its coolent out of the resevoir tank which its never done before as well.
Any ideas please as I'm supposed to be going to the Alps at the end of May on it? Might be pushing me luck there I think Embarassed

    

2Back to top Go down    Re: cant lower the idle revs on Thu Apr 02, 2015 7:15 am

sidecar paul

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Mr Lee,
For the coolant problem, check if there is a split in the tube from the radiator to the bottle.

What happens is that when the radiator is hot, the water flows freely into the coolant bottle, but on cooling, air is sucked back into the radiator via the split, leaving the bottle full, eventually overflowing.

Fortunately I discovered the split before I started to replace the seemingly failed head gasket!

Paul.


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'84 K100RS (0014643) (owned since '85), 86 K100RS (0018891) with Martello sidecar (built as an outfit in '88),
'51 Vincent (since '67),'72 Montesa Cota (from new), '87 Honda RS125R NF4 (bought 2015)
....No CARS never ever!
    

3Back to top Go down    Re: cant lower the idle revs on Thu Apr 02, 2015 7:28 am

ungaas

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MrLee -
have you removed the TPS from the TB or have you only moved it?

For my penny's worth it is better to remove it altogether(2 screws) and only then do a TB balance.

Others have had similar problems and found the TPS to have been incorrectly fitted causing a fast idle problem.


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88 K100 Unfaired 0033026

92 K1100RT 6455097
    

4Back to top Go down    Re: cant lower the idle revs on Thu Apr 02, 2015 8:42 am

92KK 84WW Olaf

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I had same issue on my RT with the pipe to the coolant bottle. But the sight tube plastic was also cracked so I replaced both tubes and no trouble since. Be careful about correctly routing the pipe to the expansion bottle and make sure you clip it in position. Mine has cable ties loose fitted to hold it in place, its possible to snag it when you are refitting the petrol tank. Also clean the radiator cap inside, but be gentle, there is a sealing ring in there. If you still have a problem swap the radiator cap.

Check the throttle can return freely at the injectors. You will see how it operates and then returns to a rest position at idle. On my LT one of the clips on the intakes was fouling the throttle and I struggled to get the tickover back down. One day I was able to push it back down to the idle position and saw what was happening, the clip was preventing the mechanism from returning to the idle position and leaving me at the same revs as you are seeing. I had toslackenthe jubilee clips and move/rotate them clear of the throttle mechanism.

Also, have seen some comments on the 'choke' cable causing a similar problem. If you haven't done it the twist grip mechanism may need cleaning up.

Given the age and lack of miles make sure you replace the fuel pipes, with all the moving of the petrol tank they will have cracked. Use BMW pipe, its not expensive and make them slightly longer so you don't need to disconnect them to get at the radiator cap or the relay box. Angle the pipe clips so if you do have to remove the tank you can access them through the side slots in the left fairing panel to undo them without having to remove the fairing panel.


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1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

5Back to top Go down    Re: cant lower the idle revs on Thu Apr 02, 2015 8:49 am

92KK 84WW Olaf

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Also,

If going to the Alps you will be using braking a lot. I have had both LT and RT give me brake master cylinder leaks. Both I suspect were laid up for a while which can cause a few issues to seals etc etc.

On the RT I replaced pads and rear disc but also ended up doing both master cylinders. The rear fluid reservoir is very prone to age cracking and it too was replaced. All new fluids. Your miles are low but so were mine.

Do all new oils in transmission and final drive, if not already done.

Take a good look at the clutch cable, if you are replacing it use the BMW one but get the little sleeve for the lever as well, it does not come with the cable!.

What date are you going? Tackler, 88KE and myself are going to France on 30th May. Mostly west and south but Tackler is staying for a month and heading over to the Alps.


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

6Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 2:30 am

mr lee esq

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@sidecar paul wrote:Mr Lee,
For the coolant problem, check if there is a split in the tube from the radiator to the bottle.

What happens is that when the radiator is hot, the water flows freely into the coolant bottle, but on cooling, air is sucked back into the radiator via the split, leaving the bottle full, eventually overflowing.

Fortunately I discovered the split before I started to replace the seemingly failed head gasket!

Paul.
Thanks for that Paul,I will check once I can back to it Very Happy

    

7Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 2:32 am

mr lee esq

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@ungaas wrote:MrLee -
have you removed the TPS from the TB or have you only moved it?

For my penny's worth it is better to remove it altogether(2 screws) and only then do a TB balance.

Others have had similar problems and found the TPS to have been incorrectly fitted causing a fast idle problem.

Hi Thanks for that, it sounds a good idea to get rid of that sensor Laughing

    

8Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 2:36 am

mr lee esq

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@92KK 84WW Olaf wrote:Also,

If going to the Alps you will be using braking a lot. I have had both LT and RT give me brake master cylinder leaks. Both I suspect were laid up for a while which can cause a few issues to seals etc etc.

On the RT I replaced pads and rear disc but also ended up doing both master cylinders. The rear fluid reservoir is very prone to age cracking and it too was replaced. All new fluids. Your miles are low but so were mine.

Do all new oils in transmission and final drive, if not already done.

Take a good look at the clutch cable, if you are replacing it use the BMW one but get the little sleeve for the lever as well, it does not come with the cable!.

What date are you going? Tackler, 88KE and myself are going to France on 30th May. Mostly west and south but Tackler is staying for a month and heading over to the Alps.
Thanks for the advice on that. We're going to the Alps at the end of May leaving England on the 28 May, but although I have a couple of problems with my K100, I've also got my leg in plaster, so I've to get over that obsticle first!! Shocked

    

9Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 3:06 am

92KK 84WW Olaf

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The leg is an issue as in you will have to do serious physiotherapy on it to get it back to strength. Don't skimp on that because there is potential to do damage. If its left leg be particularly careful as you need it for side stand and getting on and off bike. A lot of steady physical activity will be better for you. Been there.

None of the tasks you have are particularly difficult or expensive but wriggling around witha leg in plaster is a challenge.

Keep us posted on your progress and don't be afraid to ask questions.


__________________________________________________
1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 58,645 now 60,500miles
    

10Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 3:11 am

mr lee esq

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@92KK 84WW Olaf wrote:The leg is an issue as in you will have to do serious physiotherapy on it to get it back to strength. Don't skimp on that because there is potential to do damage. If its left leg be particularly careful as you need it for side stand and getting on and off bike. A lot of steady physical activity will be better for you. Been there.

None of the tasks you have are particularly difficult or expensive but wriggling around witha leg in plaster is a challenge.

Keep us posted on your progress and don't be afraid to ask questions.
Thanks for that

    

11Back to top Go down    Re: cant lower the idle revs on Fri Apr 03, 2015 10:51 am

RicK G

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If you push down on the idle adjustment screw do the revs drop, it is quite possible the throttle is staying a touch open and hanging on the cable. One other test is to let the throttle snap back ans listen for a very definitive clack as the idle adjustment hits the stop.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

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