The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: MR.E on March 28, 2012, 04:00:02 AM

Title: bugger to start!
Post by: MR.E on March 28, 2012, 04:00:02 AM
Ey up

Been getting out more on the bike recently but it's a bugger to start when cold.
with the choke on it'll cough & splutter for a while before catching good & proper.

Any ideas what it might need?
New HT leads, plugs, reset choke???

Thanks

Elliott

Title: Re: bugger to start!
Post by: Barry on March 28, 2012, 04:38:46 AM
Elliott

Have you tried starting with no choke ?

With the temperatures that we have had in the UK recently mine is starting instantly on the button without any choke at all. I know it should need choke and the fact that it doesn't would usually suggest I might be a tad rich but the plugs don't indicate that and I still get 60 - 70MPG so there can't be much wrong with the mixture. If this weather keeps up I wouldn't expect to need the choke again until October.



Title: Re: bugger to start!
Post by: Bob_Roller on March 28, 2012, 09:55:23 AM
What year bike do you have ?

What is your starting technique ?

There's a bit of technique required to start these bikes, the manual choke use, is a bit of an 'art', as compared to 'modern' bikes !!!!
Title: Re: bugger to start!
Post by: MR.E on March 28, 2012, 03:35:07 PM
Quote
Elliott

Have you tried starting with no choke ?

With the temperatures that we have had in the UK recently mine is starting instantly on the button without any choke at all. I know it should need choke and the fact that it doesn't would usually suggest I might be a tad rich but the plugs don't indicate that and I still get 60 - 70MPG so there can't be much wrong with the mixture. If this weather keeps up I wouldn't expect to need the choke again until October.




cheers, tried it without choke but not done it any good.
Title: Re: bugger to start!
Post by: MR.E on March 28, 2012, 03:39:59 PM
Quote
What year bike do you have ?

What is your starting technique ?

There's a bit of technique required to start these bikes, the manual choke use, is a bit of an 'art', as compared to 'modern' bikes !!!!


Bike is a 1981

Starting technique........hmmmmm..........
Well fuel on, 2 half twists of the throttle, choke on & wait!!!


Went in the garage tonight, and looked over carbs it would appear the choke cables have slipped (though there not cables - I fit a choke to the airbox & there the pushrod ones).
Tightened the cable & clamps back up on the right side - it's a fiddly job - and it fired pretty much straight away, now just need to do the left side!!!

Elliott
Title: Re: bugger to start!
Post by: Lucky_Lou on March 28, 2012, 04:17:27 PM
Starting Technique.
Try full choke on, no throttle until it starts to fire then just blip the throttle knock the choke down to half soon after then off after 1/4 mile. Maybe sooner in summer or March.
Lou  
Title: Re: bugger to start!
Post by: MR.E on March 28, 2012, 04:21:13 PM
Cheers

at the moment i run it for about 1/2 a mile before i turn off the choke.
it'll sometimes need to be 'tickled' at the lights within the first mile or two but then normally run well.

What oil do you use?
I'm running a 20/50w classic car oil, but sound 'tink-y' when warm (valves are set fine)

Thanks
Title: Re: bugger to start!
Post by: tvrla on March 28, 2012, 08:54:46 PM
Who woulda thought the chokes might not be working right.  ;)

(gotta be a smartass in every crowd, huh? - it's a dirty job but someone's gotta do it!)

It doesn't do any good to twist the throttle a couple times before starting. Won't hurt anything, but won't help the bike start. If the carbs had accelerator pumps, then it would deliver a squirt every time, but these don't.

The best thing is to leave the throttle closed when cranking, then hit it when it catches.
Title: Re: bugger to start!
Post by: donbmw on March 28, 2012, 08:55:29 PM
Has the bike been setting up for awhile. It sounds like you need to clean the carbs. Pull you bowl and look at the small fuel bowl for the choke system the jet from the main fuel bowl could be stopped up not letting fuel to the chocke system. When I bought the R90 I have it was at beginng of summer and it was not until cold weather came that I found this back hard to start and that one of the carbs had the choke system stopped up. After I unstopped the jet to the choke system have not had any problems.
Title: Re: bugger to start!
Post by: Barry on March 29, 2012, 06:17:20 AM
Cranking with the throttle closed and catching it with a quick blip is the classic airhead starting technique and there are a couple of reasons for doing it this way:

1. The choke isn't designed to function with the throttle open.

2. If you crank with the throttle open the starter will turn the engine over slightly slower as you are now asking it to work harder by compressing more mixture.

I also always start with the clutch pulled in to reduce the cold oil drag from the gearbox. Anything that makes it crank faster will help with starting.
Title: Re: bugger to start!
Post by: Lucky_Lou on March 30, 2012, 02:25:44 AM
Quote
and it was not until cold weather came that I found this back hard to start and that one of the carbs had the choke system stopped up. After I unstopped the jet to the choke system have not had any problems.
Ahh but you live in the Tropics and your idea of "Cold" would be a beach day in Yorkshire... [smiley=thumbsup.gif]
I am running Castrol Classic GP50 (it was on offer i know tight git) what ever you use i would stay away from synthetics in the crankcase.
Lou