Poor low speed running.

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Tony
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Poor low speed running.

Post by Tony » Tue Nov 15, 2011 11:20 pm

I have a KR1 and it has a very poor pickup from tick over and hangs onto revs before returning to tick over. I can't sort it out and have tried allsorts. I thought it must be an air leak but have have checked the inlet manifolds and all joints, cleaned and checked pilot jets and carb insides. I've synched carbs and twiddled to the point of madness to no avail. It's all bog standard settings on carbs and no bike mods. Any help or ideas would be much appreciated by me, many thanks, Tony.
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JanBros
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Post by JanBros » Tue Nov 15, 2011 11:59 pm

did you check the carb rubbers only visual ? if so, spray some start pilot or brake cleaner on them when the bike is running. if the engine runs faster when sprayed on, you have a leak :wink:

and not every engine is the same, even if it's all standard. I'd adjust the airscrew. be aware : with the PWK carb's, the screw is at the back and it controls the amount of air and not the amount of fuel like on most carbs (where the screw is at the front of the carb). So turning it in = less air = richer.

from memory, a KR1 doesn't need the airscrew to be opened a lot. I usualy start with only half a turn open - manual says 1 1/2 turn open.
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Tony
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Post by Tony » Wed Nov 16, 2011 9:46 am

I've done the brake cleaner trick but I'll mess with the pilots because I've set them at 1 1/2 as per the manual. I'll get twiddling. Many thanks for your help. Tony.
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Howie
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Post by Howie » Wed Nov 16, 2011 10:47 am

Hi Tony,

You didn't say if the bike is in regular use or not?

It does sound like a carb problem but have you checked things like the routing of choke cables/throttle cables & the smooth operation of these?

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Post by Tony » Wed Nov 16, 2011 10:55 am

The bikes in fairly reg use (got 3 bikes so I split the riding between depending on my mood or journey!). Checked all routing, lubed and double checked again! Driving me mad as it's spoiling an otherwsie perfect bike, got an KR1S too and that dosen't do it at all. Tony.
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Post by maccas » Wed Nov 16, 2011 10:56 am

I know it might be a bit of a faff but can you borrow the carbs off your kr1s and fit them to your kr1 to see if that eliminates it?

Maccas

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Post by Tony » Wed Nov 16, 2011 11:04 am

It might get to that stage but because they have different needles, pilot jets and pilot screw settings I thought it might not work properly. I'm going to experiment with pilot screw setting first, then it's going to be a carb swap I think.
Tony.
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Post by JanBros » Wed Nov 16, 2011 11:50 pm

in case you haven't found out : you don't need to take out the carbs to adjust the air-screw's :idea:

just losen the clamps. turn the right carb to the right and you can get to the screw. turn the left one to the left, and go with a screwdriver under the frame-beam, and you'll just be able to get to it :wink:
You know it's cold outside when you trip over dog shit instead of standing in it.

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Post by Tony » Thu Nov 17, 2011 9:22 pm

Thanks for the tip, it'll save me taking the airbox etc out!
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Howie
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Post by Howie » Thu Nov 17, 2011 10:33 pm

Keep us posted on what you find Tony. The only reason I mentioned the cable routing was because my old Kmx use to do the same thing. I was scratching my head for ages until I realised the problem only began when I replaced the throttle cable with an after market one :roll:

And it only did it when in neutral with the bars turned to the left #-o

A quick fiddle with the clip that held the cable under the tank & hey presto no more problem.

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Post by KR-1R » Fri Nov 18, 2011 10:24 am

as well as routing
slacken the adjuster at the throttle grip/tube end to give a decent few mm's movement before any pull on the slides
you don't want them tort on the pull/twist

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Post by Tony » Fri Nov 18, 2011 8:32 pm

Sorted!! thanks for all your help. I screwed the pilot jets to 1/2 turn out and it runs like a different bike. It's lovely and crisp off the throttle and the revs instantly drop down to tick over again. Why couldn't Kawasaki manage to do that, the settings they advise (1 1/2 turns out) just don't work??? Thanks again for all the advice everyone.
Tony.
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Post by Howie » Fri Nov 18, 2011 11:08 pm

Well done fella =D>

Quite possibly when the bike was new, 1.5 turns out would be spot on but after 20 odd years things do wear/clog etc etc

I had the same prob with the kmx as you know but also with a customers 1968 BSA bantam, bloody thing seemed to reset itself every night.

So my customer provided a brand new amal & bingo :D

That was last year so the bugger will be playing up again by now, ker-ching :twisted:

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Post by JanBros » Sat Nov 19, 2011 3:29 pm

Tony wrote:Sorted!! thanks for all your help.
that's what we are all here for :wink:
You know it's cold outside when you trip over dog shit instead of standing in it.

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Re:

Post by dmac » Fri Jul 27, 2018 5:50 pm

JanBros wrote:
Wed Nov 16, 2011 11:50 pm
in case you haven't found out : you don't need to take out the carbs to adjust the air-screw's :idea:

just losen the clamps. turn the right carb to the right and you can get to the screw. turn the left one to the left, and go with a screwdriver under the frame-beam, and you'll just be able to get to it :wink:
Blast from the past, I was searching about pilot air screw settings and found Jan's post above.

Going to save me alot of time and patience - last time I adjusted I did it the long way - going to try this way now.

Thanks Jan, Great information 8)
I used to be undecided, but now I am not so sure.

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