MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: maverick42190 on July 03, 2012, 11:25:21 AM

Title: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 03, 2012, 11:25:21 AM
I bought a 1986 K100RT over the weekend. Everything runs pretty well but I have noticed a few items that aren't major but I would like to run past the group:

Issue 1:
When I squeeze on the front brake I can feel the bike pulsing and the pads squeal.  The pads have plenty of meat on them it looks like but they are the original ones.  The back brakes are fine. Is there a way to turn rotors on these or am I going to have to buy new rotors or just new pads?

Issue 2:
The bike starts fine and idles a little rough but smooths out after 1000 revs. Sometimes, when I am coming to a stop, if I pull the clutch it it will die.  I have noticed if I engine brake to the stop then it is fine and it idles fine at the stop.  I put some techron in it yesterday and I am waiting to see if this solves the issue.

Thanks for the help.
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 12:05:52 PM
... when I am coming to a stop, if I pull the clutch it it will die.

Mine does that too :(
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 03, 2012, 12:10:14 PM
Quote
Mine does that too :(

Will it die if you just engine brake down and then let it idle at the stop or does it just die every time?
Title: Re: New K-Bike Troubleshooting Questions
Post by: frankenduck on July 03, 2012, 12:17:50 PM
The rotors can't be turned.

http://www.motobrick.com/index.php/topic,1094.0.html (http://www.motobrick.com/index.php/topic,1094.0.html)
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 03, 2012, 12:24:18 PM
Thanks for the link.  I looked at it earlier but wasn't sure if it was the same thing I was experiencing.

Quote
The rotors can't be turned.

Then it looks like I'll have to get new rotors to get rid of the pulsing, correct?
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 12:29:10 PM
Mine dies about 75% of the time after a quick deceleration unless I rev the engine when stopping. Even if the engine is hot. It's the only problem I have with the bike.

Will it die if you just engine brake down and then let it idle at the stop or does it just die every time?
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 03, 2012, 12:37:36 PM
Quote
Mine dies about 75% of the time after a quick deceleration unless I rev the engine when stopping. Even if the engine is hot. It's the only problem I have with the bike.

Mine only does it about 10% of the time so I'm probably not going to worry about it unless it gets really bad.
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 01:22:54 PM
:: My K runs like crap at idle but does OK at higher RPMS ::
http://www.motobrick.com/index.php/topic,1094.0.html (http://www.motobrick.com/index.php/topic,1094.0.html)

The thing is, it idles fine (after a minute of warming up).

It usually stalls if I pull the clutch while the bike is moving regardless of engine temp.

Title: Re: New K-Bike Troubleshooting Questions
Post by: Inge K. on July 03, 2012, 01:28:50 PM
Could be a idea to check for intake leaks below the TB`s.

Inge K.
Title: Re: New K-Bike Troubleshooting Questions
Post by: WayneDW on July 03, 2012, 08:15:15 PM
Dying is not normal.  It has never happened to me.  There must be something wrong.  I'd start with Inge's suggestion as he really knows what he's talking about.
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 08:20:12 PM
Could be a idea to check for intake leaks below the TB`s.

Will do. Thanks.
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 09:33:59 PM
I could not get any kind of a RPM reaction the other day spraying carb cleaner all over the "carbs". (Was careful to wash it all off a moment later with a garden hose.)

Just tried the propane torch method without any noticeable results either.

The bike idles fine. I can rev and release on the center stand and she'll just purr at 1k RMP. Stalls happen at red lights and downshifting while getting off the freeway. Maybe I need to work on my shifting.

Title: Re: New K-Bike Troubleshooting Questions
Post by: frankenduck on July 03, 2012, 10:00:30 PM
Try this: Adjusting the TPS (Throttle Position Sensor) on a 2V K bike (http://www.motobrick.com/index.php/topic,1522.0.html)
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 03, 2012, 10:38:59 PM
Duck - It's been set so that the slightest throttle turn clicks the TPS switch.

It was last adjusted by Phil at MaxBMW when he synced up the TB's about a month ago.
Title: Re: New K-Bike Troubleshooting Questions
Post by: frankenduck on July 03, 2012, 11:04:41 PM
The bike starts fine and idles a little rough but smooths out after 1000 revs.

I just noticed this. 1,000 RPM should be your idle.

The spec is 950 +/- 50 but they tend to run/idle better at 1,000 RPM.  Adjust the idle screw and reset your TPS accordingly.
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 04, 2012, 12:00:22 AM
Great! Thanks, duck. I'll check that out tomorrow. I have a Haynes manual but if you have a schematic let me know.
Title: Re: New K-Bike Troubleshooting Questions
Post by: frankenduck on July 04, 2012, 12:53:25 AM
No schematic required.

Adjust the idle with this screw.

Then loosen the screws that hold the TPS in place and adjust it's rotation so that it clicks (engine off so you can hear it) when any throttle is applied and then retighten them.

Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 04, 2012, 10:01:58 PM
Great, Duck thanks for the help! Once I have time I will pull the fairing and adjust the screw.  I'm pretty sure that's the problem because I left it idling today while I did some yard work and the battery was dead when I shut it off.  I forgot the alternator doesn't charge under a certain engine speed.  Do you sell the battery cover grommets on your website?
Title: Re: New K-Bike Troubleshooting Questions
Post by: frankenduck on July 04, 2012, 10:08:04 PM
No. Best bet is to get them from a dealer.
Title: Re: New K-Bike Troubleshooting Questions
Post by: argent brick on July 05, 2012, 02:04:09 AM
I remember reading about someone that had a similar problem with the front brake on their flying brick. They replaced rotors
and problem went away , but only for a short time. the real culprit was the front wheel bearings.
Title: Re: New K-Bike Troubleshooting Questions
Post by: Rick G on July 05, 2012, 06:26:43 AM
Some times there is a spare grommet on a K.  Look in the hole just in front of the rear shock mount at the top and occasionally there is a grommet in it. I have no idea what it is for but its the same and not used in that place.
Title: Re: New K-Bike Troubleshooting Questions
Post by: Inge K. on July 05, 2012, 06:49:09 AM
I have no idea what it is for but its the same and not used in that place.

Crash bars in front of the tragkorbs, often used on police models.

Inge K.
Title: Re: New K-Bike Troubleshooting Questions
Post by: Rick G on July 05, 2012, 08:12:46 AM
Thanks Inge I will put that in my knoledge bank and loose it for all time :lol:
Title: Re: New K-Bike Troubleshooting Questions
Post by: Inge K. on July 05, 2012, 03:06:44 PM
Quote
Mine dies about 75% of the time after a quick deceleration unless I rev the engine when stopping. Even if the engine is hot. It's the only problem I have with the bike.

Mine only does it about 10% of the time so I'm probably not going to worry about it unless it gets really bad.

Also check that the spark plug caps are pushed fully home and seated.

This that not quite make sense, did happen to me some years ago....

Now and then, and only during a deceleration.....it was running only on three cylinders, when adding throttle again...
the few times this did happen I wasn`t closing in to a roadcross etc. so no need to pull the clutch...
most times this did happen I was going downhill.........so two kicks with the left foot to get some more rpm
and adding good throttle opening.............welcome back #4.

It turned out to be a broken spring at the connector, inside one of the plug caps.....

I don`t say that this is the problem on your bikes, but it could be worth checking.........
Have some experience with loose caps on K`s, but only one time the behaviour has been like this.

Inge K.
Title: Re: New K-Bike Troubleshooting Questions
Post by: Inge K. on July 05, 2012, 03:10:03 PM
Thanks Inge I will put that in my knoledge bank

Put it four different places, at your 30 Terror Bite :loopy:.

Inge K.
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 05, 2012, 04:25:38 PM
Thanks, Ingle I'll check on those suggestions.  I have read about the front wheel bearing a few other places also so I am going to give that a try.  The pulsing goes away with hard braking but the wheel doesn't feel loose or anything while riding
Title: Re: New K-Bike Troubleshooting Questions
Post by: maverick42190 on July 10, 2012, 10:36:28 PM
Took the fairing off and adjusted the idle adjustment screw.  Problem with idle is solved! Thanks for the help everyone!
Title: Re: New K-Bike Troubleshooting Questions
Post by: TimTyler on July 12, 2012, 06:52:00 PM
My stalling problem went away after I calibrated my exhaust valves. http://www.motobrick.com/index.php/topic,2734.0.html (http://www.motobrick.com/index.php/topic,2734.0.html)