What make of spark plugs?Problem Solved!!!!

[scuba]

do you have point ignition system? check condenser and short cable on points. it must never touch ben can (earth).

[Bob_Roller]

The LS bikes have factory electronic ignition.

[Chris_in_BC]

The start/stop switch generally that is a go or no go. Turn on ignition and the kill switch, With your 3 idiot lights on, push the switch gently to the side and up and down (don't switch off)  Just try to move the whole switch around . If flaky the lights will go off/ on.

There is one Phillips head screw at the bottom front of the kill/ starter plastic piece. You can take it off easily and maybe spray some cleaner in the back.
But DON"T remove the circlip on the kill button and try to remove it from the housing. There is a spring and detent ball that is a real pain to get back together after you have spent the first hour or two looking for the detent ball in your workshop.  :-/

Even if your carbs are out of adjustment a real long way the bike will still run So that isn't your most pressing problem. If you rode it Sat. and it wouldn't start Sunday (before doing any fiddling) then it could very easy be coil or plugs or HT leads.
Follow suggestions of others. Lay plug on top of cylinder to ground..do you get spark? Firing on one or both or neither?

[beemer]

Well i did all the tests as recommended by all you helpful guys!thanks again for the advice! found the stop control was working ok,but i did take the time and apply some switch cleaner,the plugs were sparking well,although i did get some new ones i will install tomorrow,the major problem seems to have been the HT leads!!!i made up my own leads,easy enought to do,i'm a radio ham,not sure if iv'e mentioned this in the past,so i had some really good cable to make up the leads,the caps are fine,as soon as i installed the new leads she fired up!!!and is running as she did before,no backfiring or spluttering!!strange how the old cable can deteriate!i checked them with my ohm meter and although they were working, i guess the high voltage was causing them to break down,i also went through all electrical connections,so,all back to normal,i hope she starts in the morning!!!!thanks again everyone,J.

[Bob_Roller]

Did you use copper conductor or resistor type wire ?

Our bikes use non-resistor leads, and resistor spark plug caps.

[Rob Valdez 79 R65]

Along with the fuel line mentioned in another thread, HT wires and caps are two more items I treat as consumables and replace every 2-3 years.

[beemer]

Did you use copper conductor or resistor type wire ?

Our bikes use non-resistor leads, and resistor spark plug caps.

I used copper wire which has a corrosion tin plating,it consists of 2 inner conductors,a insulater,and a braided outer conductor,and a final tough outer sheath,all wires were strapped and solderd together and then soldered to the brass connector stub that fits into the coil,this is used in my ham radio hobby to handle thousands of watts of RF power,and will handle very very high voltages,the caps are fine,and have a capacitor fitted,the impedence match of the new"home brew" HT leads and the old are the same,the bike now runs fine,i have new plugs to fit also,but the ones fitted now are fine,i guess these are the problems one can expect if the bike hasn't been used for some time,i'm very pleased with the results from these HT leads,let's see how long they last!!!cheers,J.

[montmil]

the major problem seems to have been the HT leads!

Guess I should've chimed in earlier...

When I drove to Austin, Texas to check our my new/old R65, the current caretaker (not!) could not get the machine to start. Hum. Me, with my decades of experience in such matters, showed the lad how to turn on the fuel tap. This is a true story. Really.

After getting the bike lit up, said lad mentioned the bike was cold natured and that was why the left cylinder was missing, sputtering, backfiring, richly smoking. Hum. Number two of several hums to follow.

I rode the bike down the drive and turned onto a small residential street, all the while feeling the left jug starting and stopping. I went around the corner, parked, and looked. Sure 'nuff... the left plug HT lead was laying directly on the engine top cover and there was a burned spot where the plug lead was arcing to the engine case.

I moved the lead, the engine cleared up, and I eventually negotiated the poor guy down about 25 percent of his asking price with that issue and several other maintenance concerns.

This here R65 forum is helping me rehab a basically solid 1981 scooter. What I continue to be pleased with is that the bike's needs are basic. Nothing over the top. Old wiring. Poor grounds. Corrosion on terminals.

Check the simple stuff first. It usually don't cost nuttin'. And, as you have discovered, there's a number of fairly bright folks living here. Enjoy the ride.

Monte

[Justin B.]

Spark plug caps with capacitors in them?  That's a new one on me, where did you come up with that idea?  Usually caps are used that have a certain amount of DC resistance, especially important for keeping the electronic ignition models happy...

[beemer]

Spark plug caps with capacitors in them?  That's a new one on me, where did you come up with that idea?  Usually caps are used that have a certain amount of DC resistance, especially important for keeping the electronic ignition models happy...

They are known as anti interference type,you surely must of heard of that!!the capacitiors are built in to stop people picking up your ignition noise on their radio or tv!
Look here    http://www.freepatentsonline.com/4082980.html

[Justin B.]

Interesting, sounds like one of those "Install and double your HP while decreasing fuel consumption" snake-oil products.  It's always been my understanding that resistor caps/wires were used for RFI suppression.  The abstract you linked to indicates the capacitor caps are for "intensifying" the spark...

[not-so-fast-ed]

Like yourself Justin, I've always considered the ignition spark "Radio Frequency Interference" noises to be handled by the resistance portions of the wires/plug caps/sparkplugs.  Electrical generation noises and blower fan noises were handled by capacitors.  The capacitors tended to act like shock absorbers and smoothed out the fluctuations/noise.  Of course they have had their uses in the sixties to produce a hotter spark from a "Capacitor Discharge Unit" ignition system. a sometimes favorite of "Hot Rodders".
Never forgetting the dampening effect of a capacitor in a points ignition system.
Plug caps with built in capacitive discharge abilities might be a great subject for a comparison test if Beemer can get some objective observations from a dyno pull or other equally valid documentation.
I wouldn't mind buying some "Snake Oil", if I believed it would improve performance without hurting the engine.

[beemer]

Interesting, sounds like one of those "Install and double your HP while decreasing fuel consumption" snake-oil products.  It's always been my understanding that resistor caps/wires were used for RFI suppression.  The abstract you linked to indicates the capacitor caps are for "intensifying" the spark...

Does it really matter?iv'e posted the info,it's up to you to believe or disbelieve it?iv'e been working in electronics all my life,hence my ham radio hobby,wether you think it's valid or not is entirely up to yourself,we all have our own opinions,cheers,J.

[nhmaf]

Even regular resistor plugs have some capacitance to them, so I suppose that with a plug cap that incorporates
a specific capacitive component with the (primarily) resistive component, that can create a more effective
1-pole RC filter for very high frequency noise suppression.

There is also a newly introduced "spark plug" product that has its own form of CDI type circuit intended to generate
a much more energetic spark.    I don't know how good these things are, and they claim to produce a very intense, rapid
spark.   If there happens to be one of an appropriate reach, heat range, etc. it might be interesting to try in an airhead.
But, if your timing is off, particularly if points are worn and the timing is retarded, I could see these as possibly making
a bad thing much,much worse.  Here is a link to it -

http://www.pulstarpulseplugs.com/default.asp?KID=3340

Hmm, initial search with the website turns up no matches for the typical airhead plugs, so this is probably an academic exercise only,
though if someone wants to try these in their car and write up a report that would be cool..

[Bob_Roller]

At $25US per sparkplug, I think I'll pass until I see some 'real' world results.