Slight hesitation coming off tickover - lazy post :-)

Kenny

Kenny

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I know it is a bit of a lazy post and cannot believe I took 'Giles' type photos either !! 😁


I have a perfect little R45, never owned one before and never had this 'problem'. On tickover fine, usual running is perfect as well ( carbs all balanced ) ....it is just that there is a hesitation from pulling away off tick over but after a little rev all is fine. I believe the photos show the sparkplugs as slightly rich. Do I screw in mixture screw in 1/8th turn. Gammy knee at the moment so cannot ride her just yet. Hey, short days so thought I'd test some of you out. I believe screwing in pilot jet at increments of 1/8th may solve the problem. Carbs rebuilt by splendid last owner and balanced by Moi.
 

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Kenny said:
I know it is a bit of a lazy post and cannot believe I took 'Giles' type photos either !! 😁


I have a perfect little R45, never owned one before and never had this 'problem'. On tickover fine, usual running is perfect as well ( carbs all balanced ) ....it is just that there is a hesitation from pulling away off tick over but after a little rev all is fine. I believe the photos show the sparkplugs as slightly rich. Do I screw in mixture screw in 1/8th turn. Gammy knee at the moment so cannot ride her just yet. Hey, short days so thought I'd test some of you out. I believe screwing in pilot jet at increments of 1/8th may solve the problem. Carbs rebuilt by splendid last owner and balanced by Moi.
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Kenny

I had these set as per the Bing recommended settings (1/2 turn on idle mix setting) and didn't have this issue so not sure what has changed

Screenshot 2024-12-15 at 14.43.15.png
 
Before reaching for the mixture screw, this sounds like a throttle cable imbalance (one carb getting it slightly before the other). But like all such things, it's best to start with valve clearances and timing then go to the carbs. Like a proper service.
 
Have to say, my first thought was throttle cables.
 
Gelandestrasse said:
Before reaching for the mixture screw, this sounds like a throttle cable imbalance (one carb getting it slightly before the other). But like all such things, it's best to start with valve clearances and timing then go to the carbs. Like a proper service.
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It's got brand new throttle cables and I had balanced it before selling it , valves were also checked and set and timing was checked with a strobe light . As I said I did not have this issue so would check the simple things like a cable hasn't been dislodged from its ferrule or a HT lead/LT slightly dislodged as it was transported a few hundred miles on the back of a trailer
 
I think you got it right in post 1 Kenny. If the mixture is a bit rich at tickover from the pilot jet then as the main jet cuts in the motor chokes slightly. By weakening the mixture this may solve the problem. Its a low cost no cost trial , that can easily be reversed.
 
steve hughes said:
I think you got it right in post 1 Kenny. If the mixture is a bit rich at tickover from the pilot jet then as the main jet cuts in the motor chokes slightly. By weakening the mixture this may solve the problem. Its a low cost no cost trial , that can easily be reversed.
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Agreed, bike bought/presented in perfect condition, so hopefully 'maybe' get in a 20 mile test run tomorrow and report back (y)
 
I’ll go with throttle cable take up balance ,
The bike was fine a few weeks ago when delivered/ collected.
If the balance is good,
Maybe some debris in the carbs as it’s been stood a while,prior to recommissioning.
The air bleed on the main jet can pick up crap quite quickly.
If ,you’re 100% happy it’s not balance.
The issue you are getting is to do with the transition from idle jet to main jet assembly.
The initial transition is performed by the slide needle and its seat jet.
An air bleed blockage could make the transition rich as could a worn slide needle and / or seat jet.
Worn needle or seal jet wear is hard to see and best just dealt with by replacement.
Of course the needles could also have the circlips fitted in the wrong groove.
All of the above is far more likely to be the cause than the idle mixtuse screw being 1/4 turn out of adjustment.
 
I didn’t replace the slide needle or jet seat as they looked ok but bow to Mikes far greater knowledge that even though they looked OK they could be worn . Needle clips were installed as per Bings recommended settings . Some dirt in the carburettors is quite possible as the transporting of the bike could have dislodged some dirt in the system


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Now I realise this is the R45 featured in John's blog. I admire the rebuild and have no doubts to the bike's condition when sold. I have found with replacement of cables, especially new ones, is that initial use (first 1000 miles) things 'settle down' and go out of adjustment. So it doesn't matter if they are new, it doesn't mean they are in perfect adjustment after use.

And Kenny, have you confirmed exact balance of carbs by yourself?
 
Gelandestrasse said:
Now I realise this is the R45 featured in John's blog. I admire the rebuild and have no doubts to the bike's condition when sold. I have found with replacement of cables, especially new ones, is that initial use (first 1000 miles) things 'settle down' and go out of adjustment. So it doesn't matter if they are new, it doesn't mean they are in perfect adjustment after use.

And Kenny, have you confirmed exact balance of carbs by yourself?
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Agreed , I had only done 400 miles since the rebuild
 
Removed pilot jets and used carb cleaner. Both carbs balanced perfectly by Mr Nicholsen ( and checked today, again ). Left everything as is and she appeared to clear her throat...so for now, whatever it was, has resolved itself?:duno Happy days:steptoe.

Did notice at 6,000 rpm there was a stutter ( fuel starvation ?) which went away when I changed to top gear so maybe ( nothing to do with this current posting ) in the spring I'll probably check the float heights ( I say 'probably' as this bike isn't for thrashing - have a ZX4RR:tarka for that 😁 ). She has been rebuilt to a very high standard and runs very, very, well for 44 years of age:bounce1

Thanks for the replies guys, all appreciated(y)
 
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