Hiccups at cruise - '82 R65LS

[Red_Hen]

Hi Gang,

Hope everyone has had a fun & safe riding season.  I didn't get as many miles in as I'd have liked but certainly have had some fun rides!

On the last a couple rides on my R65LS, I'm cruising along and all of a sudden a quick hiccup - like someone shut off the ignition and quickly turns it back on again.  Also, getting a little more popping nose on deceleration - my K75s does that so I'm not overly concerned about that.  Valves were recently adjusted so I think I'm okay in that department.  I may re-balance the carbs in the Spring.

About the only area I haven't gotten into is the Bean Can.  I plan to take her off and disassemble, clean and replace the Hall sensor.  My carbs are only about a year past a complete rebuild, including new diaphragms and my coil & spark plug wires/caps are new.  Somehow, I'm thinking the sudden hiccup could be bean can - I have a voltmeter and voltage is consistently pushing 12 volts.  Open to your suggestions.

Thanks much,

Ken

[Bob_Roller]

Does the tachometer go to '0' when this happens, or at least heads in that direction when it happens ?

[Session101]

does your hiccup backfire?

[Bob_Roller]

Mine did when it happened, it was more of a small explosion, than a backfire !!!!!

I'm surprised the rusted cracked mufflers held together !!!!!!

[Red_Hen]

No - just a quick on/off sensation - like turning the switch off and quickly back on.  Tach needle doesn't change.  Hiccup doesn't backfire.

[montmil]

Before you start throwing money at the bike, Ken, do a very thorough check of all electrical connections and grounds, especially those related to ignition.

Vibration could be the culprit. Or corrosion in connectors. Clean up all grounding points.

It's a stretch, but when was the last time you freshened up the heat sink paste between the ICU and it's heat sink? Sneaky little devils, they are.

Doesn't sound like an ITU / bean can issue... unless the wiring connectors are dirty. Be sure you have not pinched the bean can leads between the front cover and timing chain case, causing an intermittent short.

It's something simple, simple, simple. Now go find it, Ken.

[Red_Hen]

Hi Monte,

Glad to see you're back and on the mend and ornery as ever!

Not sure I've approached my Ignition Control Unit before - I did replace the Werhle unit like the one you bought from Rick Jones - is that the ICU?

I haven't used any heat sink paste ever - I have, however, recently cleaned all (most?) my connections on the bike and used dielectric grease.

[steve hawkins]

If the rev counter - i.e the ignition did not move, and you coil and HT circuit is fine, I would be looking at fuel or a contaminent thereof.  

If your tank screen is intact or, if you have them, extra filters are ok, I would check your float bowls.... looking for signes of water or a little debris or some such.

If you find water, I would drain your tank.  Too much washing of your bike or leaving it out in th rain, or crappy fuel can be the culprit.

I have had this with my R100, normal round the town running is not normally an issue as the water sits in the bottom of the bowel and does not get drawn into the engine - hence the 'cough'.  But if there is a lot, in the 'cruise' it can almost act like a diaphram issue.

Just another thing to add to your list of worries.  Curiously, I have never done this paste thing that people talk about - perhaps we Brits get away with it in our climate.

Rev. Light

[Red_Hen]

Thanks, Steve - it could be bad gas or too much Ethanol - carb engines are always more fussy than fuel injection.

Monte - what is the procedure for applying heat sink paste to the ICU?  Does anyplace sell the paste?

[montmil]

The Ignition Control Unit is under the fuel tank and forward of the relay stack.

It's the black "block" mounted vertically on an aluminum heatsink. There is a long, muti-wire connector at its bottom.

Removing the ICU will be obvious once you see it. The ICU is "bonded" to the heatsink with, wait for it... heat sink paste, available in small tubes at any Radio Shack.

If the existing paste has hardened, it may be necessary to gently pry the ICU free. Gently. Clean off all the old paste and apply new; using enough to get a slight squeeze out around the perimeter.

Refit all and call it done.

[Bob_Roller]

Just a note about the ICU's there are some that are bonded to the heat sink, you can't separate the two without damaging the ICU itself .

I believe these are later parts, possibly the mono shock bikes, but there are some that were OEM spares as well .

[montmil]

True, Bob, but Ken's '82 is going to be have a removable ICU... unless he's replaced it with an oddball bit.

BTW, these Bosch ICUs are found in many German automobiles, including my 1986 VW Cabriolet and can be purchased for far less money from several sources including my favorite, Autohaus AZ in Phoenix.

http://www.autohausaz.com/

[Session101]

dammit so since this post my bike was doing the same now...
i still think its coil related, basically the same with my bike, it turns off, then it backfires because it turns on again and there's fuel/or no fuel in the cylinder, also have notice that on my tach that the rpms would jump randomly up but no change in motor sound.... weird stuff and i have cleaned every connector in the system, also this seemed to have happened today when the bike was running hot too...

[Red_Hen]

Thanks guys - I only have a few rides left before it gets cold and I start getting busy again with work related stuff.  When the time comes to winterize, I plan to change der fluids, remover de bean can, and remove de tachometer.  Wirespokes is gonna spruce up my tach - he did a great job on repairing my tripmeter & cleaning up the speedometer - the speedo & tach don't look like they belong together at the moment.  The redline is yellow and spokes says he can paint it red for me & get out the cobwebs surrounding the idiot lights.  
Bean can needs to be explored and will redress the ICU with fresh heat sink paste.  After that, I"m sure they'll be other issues - there always are!

Thanks again!

[montmil]

I like "Tina Patina".  A mature babe that's kept her good looks. [smiley=thumbsup.gif]