Carb problems

[redsoul]

More newbie questions lol.....Bike ticks over great when started and even after a few miles and warm ticks over nice at about 1700 revs but after a good ride about starts revving higher and higher in neutral at a standstill...reaching about 3000 revs.Have checked cables etc and nothing seems to be sticking.
Any ideas guys??/

 

[Thunder]

More newbie questions lol.....Bike ticks over great when started and even after a few miles and warm ticks over nice at about 1700 revs but after a good ride about starts revving higher and higher in neutral at a standstill...reaching about 3000 revs.Have checked cables etc and nothing seems to be sticking.
Any ideas guys??/

1700 at tick over is way too high to begin with.

Which bike and what carbs?

 

[redsoul]

Its an r80gs(1992) with 32mm bing carbs.

 

[Kenny]

Tickover at about 1000 rpm ( when hot the charging light should just be going out )...(older BMW's can have their tickover down to 800 rpm)

Make sure you have 2 - 3 mm of slack in the throttle cables at the carbs - very important.

 

[redsoul]

Both throttle cables could do with changing anyway and i have bought 2 new EZ springs to put on....Will get the haynes manual out and see how i get on.Is it a straight forward job to do??

 

[Steptoe]

Tickover at about 1000 rpm ( when hot the charging light should just be going out )...(older BMW's can have their tickover down to 800 rpm)

.

My 1992 R100GS ticks over at 600 rpm My 1150 at 750rpm

I do like a nice slow tickover. Sign of a good engine.

 

[Steptoe]

Both throttle cables could do with changing anyway and i have bought 2 new EZ springs to put on....Will get the haynes manual out and see how i get on.Is it a straight forward job to do??

Set the tickover/idle with no cables attached before you fit the new ones

 

[Kenny]

My 1992 R100GS ticks over at 600 rpm My 1150 at 750rpm

I do like a nice slow tickover. Sign of a good engine.

Show off !!!

 

[redsoul]

The mixture screw was out alot further than the haynes manual stated so put back to stated settings but tick over was still 1800 revs when hot so turned just a little more and got it down to 1100 revs(happy with that)
The tick-over was fine untill i took the bike to a mechanic to balance the carbs lol.

 

[brassmonkey001]

Choke mechanism might be sticking.

 

[redsoul]

Choke mechanism might be sticking.

You are absolutely right..the right hand one does but i always make sure i push it back down manually..think i will order 2 choke cables to go with the throttle cables as they look pretty fecked as well

 

[Padmei]

Are most choke mechs quite stiff to turn? I rebuilt my carbs & neither seem particularly 'loose' for lack of a better word.

The old rusty spring on one side hasn't enough grunt to close it properly. I have new throttle & choke cables on but not adjusted correctly yet.

 

[brassmonkey001]

Are most choke mechs quite stiff to turn? I rebuilt my carbs & neither seem particularly 'loose' for lack of a better word.

The old rusty spring on one side hasn't enough grunt to close it properly. I have new throttle & choke cables on but not adjusted correctly yet.

No, they shouldn't be 'stiff' as such. There should be some slight resistance but the spring should be able to close it.

 

[r100gser]

high tickover

if the problem gets worse when the bike is hot - check the valve clearences - especially the exhaust side.