okay,excuse my ignorance here,but came home from nightshift to try and determine whether my ignition needs the adaptor harness(as auction closes tomorrow),i'm stumped,what looks to be the ignition module appears to be below the battery box/holder.As i am no wrench but would like to learn more about the bike(without making new problems along the way)it would seem that i would have to remove either the battery box(which appears to,but may not be welded to oil tank,or the oil tank,and or the starter motor?,am i missing the obvious here,or showing i'm outta my depth (i've got broad shoulders you can be straight up),one of the concerns i have is how many thing s do i remove to access it,but more importantly,what else does my moving these things i CAN see affect things i CAN'T see,1 thing that looked to happen was if i removed battery box(if it isn't a weld holding it) is it looks like there is circuit breakers and their associated wires bolted to it,or if i didn't have to remove these things and could in fact undo the 2 module mounting bolts am i going to be able to unplug the various wires and re attach them almost blind?.Sorry for all the what may seem 'dumb' questions ,but whilst at work i thought i was gunna come home remove a cover or 2 to either see the 6 or 7 pin plug set up,or a part # stamped on the module so i could bid or as you guys have suggested replace module,on that,what would i be testing for?continuity between each plug and?, being that it'll be removed from the battery and anything connected to it?,stop me anytime,i'd hate to make an **** of myself clogging up your forum,i'm 41 and have been riding road bikes since 15 but have only recently collated enough decent tools and confidence(haha) to have a crack,thanks yet again

 

Welcome .
If you are confident that there are no carburation problems " including leaking gaskets etc. " and the motor itself is ok., then that leaves us with the spark.
My own experience with electronic ignition control moduals has shown that they either work fine or dont work at all and you will have no spark .
If i understand correctly , the motor runs ok. when starting off on a run and then starts to crap out under load when part way through the run ?
If this is the issue i would suggest your coil is failing.
See page 8-15 of manual #99483-90
If you dont have a manual , get one .
Coil test states... coil primary should read 2.5 - 3.1 ohms.
Secondary should read 11,250 - 13,750 ohms.
Look for a crack in the coil housing also.
In short ... coils tend to fail as you have described , they will be ok. cold but after they warm up during a run they will become weaker .
Hope this helps.

 

hi machinehead ,thanks for taking the time to reply,coil was buggared(1 terminal looked completely burned out), that much we have determined,so in a way iguess my theory was to work backwards from the only ''definite'' fault we could find.What i am curious about is,my initial concern and reason for taking it to my mechanically minded friend was it cutting out/firing intermittantly which tended to happen mainly when powering on from a near stop,also,after googling causes for coil failure,found corroded ground wire to starter relay.As opposed to an intermittant no spark type of fault before the bike doesn't feel in anyway like it's going to let you down,idles well,starts good,it;s just that ,almost on cue,if i was to wind throttle on too fast,or,once i get to a certain rev(guessing 2500/3000 rpm) it starts to fart,not in a i'm gonna cut out kinda way,as soon as i back off it's sweet,it feels as if i'd be able to ride all day ,IF,i didn't have to go up a hill or pass traffic,

 

I work on quite a few older Japanese motorcycles. When they start acting the way you describe I know it's time to clean the carburetors. It may have been mentioned and I might have missed it but have you clean the carburetor? This sounds like a fuel delivery problem to me.

 

yeah mate,twice,and checked float and jets and intake,tank,fuel lines,cleand fuel filter,petcock,i'm 300ks from the nearest dealership with dynotune facilities and no-one at the motorcycle shops in town will test it under load so i'm doing the best i can,with the help from you guys and the net,i'd hate to trailer it up the road for them to discover it's something i could've fixed myself,i have the factory manual,unfortunately for my skillset,whilst i can follow the wiring diagram,it reads simple when they say replace this or check that,in reality,in some cases,it looks like removing a bunch of things to get to said part MAY be do-able, getting into these places to reattach the stuff i removed is where i can see myself creating a new headache,i'm certainly learning heaps already which always helps when you're passionate about your bike and as embarrassing as some of my questions are i'll be proud as punch if i can post on here what i have found one of these days,really appreciate that people are offering the advice,as old school as some of us are,you gotta love that technology allows forums such as this, cheers

 

You are asking all the right questions "little budda" and that is appreciated ., especially were uncommon misfires etc. are involved .
My opinion is same as stated earlier ... the ignition control unit will operate normally or not operate at all and you will have no signal to the coil to fire the plugs. If you are certain that the carb. and the valves etc. are ok. then i would look to the coil and associated connections .
Repair or replace the bad connectors and ohm. test the coil as previously descibed . Also check the coil body for cracks.
FYI ... coils usually fail in a way that you have described . They will operate fine at start up and after heating up during a run they will begin to provide less and less power to the plugs to fire under loads such as you describe.

 

i shoulda stated that it has a new coil now and since then it doesn't die intermittantly now but makes a ba-babababa-ba(so much easier mimicking sound i tell ya)when throttling on,i will do some tests working back from coil though,gotta sick daughter to look after yet again today so look forward to getting out in the garage tonight or tomorrow,thanks again

 

just waiting to get bike back from engineering workshop to remove stripped rh handlebar bolt(still need in there to test killswitch/ignition wire) and io bloody also snapped the regulator mounting stud, so will get back into trying to diagnose in a day or 2,cheers

 

Whereabouts in NZ are you? These misfires drive ya nuts but are usually something stupidly simple.

Yours could be anything from carby issues to ignition...If you are north of Auckland I can take a look at it for you...first time is free....still cheapo after that...especially compared to Auckland H-D Dealer!

But assuming you are probably way down in the King Country or Ruakokoputuna and can't get to me....I would check carby diaphragm, needle and intake seals. Accelerator pump diaphragm and stuff like float height, fuel tap filter before assuming its electrickery.

But first of all I would put new plugs in it...Evo Big Twins will run like ***** if the plugs are just slightly dirty.

What jets are you running and what pipes/air cleaner?

 

thanks for the offer spanners 39,i'm in invercargill,can't remember the jets, will find out,my mate that did the fuel check stuff did take the jets out and gave the #s to his mate at mciver veitch harley dealership in dunedin(the nearest hd)and they were supposedly correct, i have had it 3 years(bought from wellsford) and it has run pretty sweet until the it started cutting down to 1 and intermiitanly no cylinders, coil weas fried and replaced and now it is doing symptoms as described in my previous posts,i got it back from the engineering workshop yesterday(e striiped handlbar control screw,and busted regulator stud),so on my next days off will do the ignition switch/killswitch multimeter test,if you know though,1 thing i am a bit uncertain of is how to check the continuity/resistance of the regulator wirer that runs to the main circuit breaker,1 part has already had a join put in place and i noticed yesterday that there is a little bit of exposed wire a bit further along,i get the place a probe on the circuit breaker part,but ,as the regulator is a sealed unit i am unsure of how and where i would attach the other probe(just anywhere on the regulator,or on a mounting post), thanks again for your kind offer,wish i was a bit closer to your neighbourhood mate,oops,running screaming eagle hi-flo,and v&h short shots