I've done the hair drier test on the Hall sensor & engine seems to run fine when the sensor is warmed up....
any other ideas

from... https://www.k100-forum.com/t5739-wanted-130-90-17-back-tyre-and-k100-offside-pannier


no longer need HT lead - replaced that but still running v. lumpy under ~2500 RPM...any ideas...will trawl forum for tips...


Regards your lumpy running, I would be looking for air leaks.
Is the oil filler cap tight?
Are all the blanking plugs on the 3 front TB's and the hose on the rear one?
Is the engine breather hose knackered and leaking?
Leaks on the inlet rubbers? Fiddily job to replace but can be checked first.


meant to say the poor running under 2000 revs only happens once the bike has warmed up...


Based on the additional info about happening when warm, I would be thinking of the Hall effect sensors.
They live behind the 'T' shaped cover on the front of the engine, so easy to get at. They trigger the ignition. Not unheard of for them to play up when warm.
If you do a search on the forum you will hear from others who have gone before you.
Basic way of checking them is to take off the cover and heat them with a hair dryer on a cold engine  without starting.
Then start up and see if the fault is there.

My hall sensors failed when hot. The bike stopped till they cooled not shirty under 2K.

How about a throttle body balance. "Carby tune". Made a huge difference here, or did it just mask the air leaks     

Hi Markzz.
Was just going to make the same suggestion as Robin has.
I have a set of Carbtune gauges and have done it before if you need a hand to sync the injectors. Not a big job to do.
Never, ever be tempted to adjust the linkages between the injectors. They are factory set and are almost impossible to get right again if fiddled with. Unless a previous owner has...
Another one to try is unplugging the TPS (also known as the butterfly switch) on the end of the injector actuating rod. It can run fine without the TPS and is a popular mod for smoother running when slowing down. Done it on mine.
If it runs better with the TPS unplugged then you know where the problem lies. 
The K owners mantra. Always start with the cheap stuff first.

Hi Comberjohn
I'll try the TPS trick...that'd be great if u can sync the injectors on it...I'll PM u...

What year bike is it?

Rabidchiwawa007 wrote:What year bike is it?

Its a '90 K100LT with 57k miles...thanks to Comber John for sorting the injectors balance & TPS trick...running sweet now but still lumpy when warmed up...am going to try non 'R' plugs (mine are DR7EA) & maybe these tests on Hall sensor & coils...http://tinyurl.com/qz777at
~M.

Markzz wrote:...am going to try non 'R' plugs (mine are DR7EA)

can rule out the plugs...the D7EAs made no difference...damn!

Mark

Good to see you getting in tune with Comberjohn. Are you going to join us on our breakfast and our run at Stradbally on Saturday 10th? We are meeting for breakfast 9.30am. Love to see you along and the breakfast is good. We have about 10 or 12 of us showing up. I know its quite a way down but its motorway apart from last 6 miles. Comberjohn and GMcQ have been a few times. Comberjohn is coming this time. Always a nice rideout and breakfast and lunch. And of course good company! Look up Irish Eccentrics.

Olaf

92KK K100LT 193214 wrote:Are you going to join us on our breakfast and our run at Stradbally on Saturday 10th?
Olaf

Hi Olaf, sounds great & Comberjohn mentioned it but I'm in Mayo then so hopefully will make the next run...if my brick is flying...
Have a good one
~Mark

Hi Mark,

Good to see you were already on the radar. We might have a trip up north in September, rather hoping we will as we had a nice one last year, organised by Comberjohn. Must talk to Comberjohn about that as his patch is awesome for routes and cant do it without him!

Must be nice attractions in Mayo. Bjorn goes there. You go there. I go there......

Maybe we should turn a thought to a weekend in Wetport Westport. Great camping in Westport House and a Carlton Hotel on the waters edge at the entrance.......

A Sept run out up this way sounds good Olaf...I'll be bikeless in mayo this time...its a family bash so am in caravan in achill & mulranny...

RobinW wrote:My hall sensors failed when hot. The bike stopped till they cooled not shirty under 2K.

Am hoping this issue of lumpy running under ~2500rpm is solved...found & removed some wee metal shards stuck to Hall sensor magnets...not sure where bits of metal came from...anybody had this before or is it likely to have been the cause...

Ahh Ha I have never seen that but understand how it would cause a big problem.

RicK G wrote:...understand how it would cause a big problem.

yes, I'll see how it goes over the next while...