Gidday guys I'm new to this forum and I've joined in the hope of some exchanges of ideas and knowledge but initially I have a 1988 softail standard that I'm having trouble getting to run properly, she starts great, idles well, runs well but when she warms up she starts coughing under any acceleration and runs crap unless at low revs. I've drained and cleaned the carb also replaced the ht leads and spark plugs is it possibly the coil failing when warm or am I on the wrong track. I really want to fix her as shes an old classic and was such a pleasure to ride until she started playing up. Many thanks in advance for any info or ideas offered.

Regards Shrekster

Hey mate,

Welcome to the forum, if its coughing and spluttering it is most likely the carby. I have a similar problem with the 98 Dyna I just picked up, she struggles a little when you crack it. Pretty confident that the bloke I bought it from was a bit of a backyard hack, he's played with the mixture and idle (you can smell it running a little rich); find the factory settings for your carby (assume its a CV) and start again. I've been reading the HD service manual I picked up and it says that there is a plug at the back of the carby that is put there to stop you messing around with the mixture; mines missing, if yours is as well might a good place to start.

Hard to say without seeing it in action, but sounds like a similar problem to what I currently have.

Good luck mate

Waz

Thanks Waz,

for your welcome and prompt reply, Im pretty sure it is an aftermarket carby on her as it has a Kuryakin air cleaner and a few other mods as well. She desnt actually struggle when I crack it but she actually nearly stops in her tracks like she's starving. I will have a look and see if i can find out if the carby is original or not and see how i go unfortunately circumstances dont allow me the luxury of a mechanic at the moment until I get back to work but soon I hope , meantime I'll see what I can sort with regards to your info and once again thanks heaps.

Shrekster

possibly cam position sensor in th nose cone?....had similar probs til replaced..sometimes will see visual degradation with goo melting down th wires exiting cover...link below for more experiences...
http://www.hdforums.com/forum/evo-classic-models/137936-cam-sensor.html

Thanks kiwidave I will check that out when I get a chance and get back to you along with a photo of the carby too. I really didn't want to start mucking around with the carby as I have had nothing but bad luck with toying with them in the past hahaha. I really luv this old girl and can't wait to get her running again.

Cheers all

A huge Grassyass to both Kiwidave and Jimbo for your input I have spent the day tooling with the softy and have come up with these details so far with regards to voltage and also got a photo of the carby. 

Volt Readings

Key off.                           12.45 V

Key on.                           12.43 V

Key on / Lights on.        12.10 V

Idling.                              12.76 V

Reving.                            8.0 - 14.0 V

After warm up.                12.51 - 14+ V

This sensor that your talking about Jimbo I assume that it is on the side of the crank case. Are they easy to test or check with a multi tester or do I just check if it's soft as was described in the link you provided. 

Once again I can't say snuff how much I appreciate your advice. 

Thanks for that dave,
I had a look at your post on the GB site and yes that's pretty comprehensive and I'm not scared to say a little over my head at the moment but I'm gonna sit down an have a damn good read of some stuff and see if I can actually nut out some of your advice without setting my bike on fire lol.

Actually if by chance the battery wasn't charging correctly and it was causing the bike to sputter for want of a better description would the battery not have enuff charge to even start the bike afterwards. Just a query. ???
Thanks heaps mate.
Shrekster.

apologies for th bit of a bum steer on th 88 nose cone set up guys ( tho well documented that nose cone ignition modules can indeed meet th same fate from heat?)....my experiences have been with my later '94 Evo that have never been able to afford to take to a shop since first purchasing near new, way back....had to try to learn for meself if i wanted to keep those wheels turning eh..!
Anyhoos, fwiw, heres a further coupla links of another experience i had with a dud charging system....hope its of some help to you shrekster...im sure Kiwidave will fill you in if theres any differences to yours in this regard too..cheers
http://dinosmc.com/Tech/new%20stator/New%20Stator.htm
http://dinosmc.com/Tech/nnew%20stator%202/stator%202.htm

Cheers guys and don't sweat it Jimbo all cool mate advice is advice - whether it's accurate or not, helpful or otherwise it is all put forward with the best of intentions and believe me it is certainly appreciated and taken as such cause as far as this electrickery goes mate I wouldn't know my ass from my elbow but as Baloffski put it "Online and Inline" it has opened my eyes to a genre of maintenance that I should really have paid more attention to years ago and given me a new challenge to say the least.
BUT !!!!
Hmmmmm,
My confusion continues the old girl starts no problem after I stop her after a sputtering session and even though the volts are low they don't go below the current batteries " normal " 12.4 odd volts so I would be reticent "shit bit big a word for me today" to suggest that maybe it's not a charging issue. Perhaps I can isolate whether it might be as discussed before a coil or ignition module problem with it breaking down when hot maybe ???. Is ther a way that I can test the coil or would I be advised to just replace it and see whether that sorts the problem out.

once again thanks boys. 

shrekster. 

Gidday Bangkok Bob,
Thanks for your input I'm pretty sure it's not a fuel issue as I have recently installed a brand new set of 6 gallon tanks and replaced all the fuel lines and filters etc on her as the previous owner had left her sitting for about a year and she had rust in the tanks due to condensation. Which was all successfully removed from the carby before I replaced the plugs and HT leads. So hopefully a process of elimination will sort the problem as finance permits (hahaha). I will persevere with her as I have a soft spot for the old girl and she sure is fun when she goes well (and believe me she goes real well).
Thanks again fellas.
shrekster.

I tried tracking down an intermittent muss on my Evo and in the end just replaced the ignition system. It did the trick.

Gidday Tussuck,
Yeah I'm considering new electrics ie: stator, coil, regulator, rectifier etc etc etc but wondering if it might be worth putting EFI like the newer models or if that might be going over the top.

A checklist to start with:
- What model carb are you running - you need to have a look at the side of it for the numbers or attach a pic.
- What size pilot jet is in there
- What size main Jet
- Do you know what needle your running
- Remove the small round cover off the cam nosecone and tell us what Ignition system she is running - is she still stock or aftermarket
- Single fire or duel fire?
etc

I would stay away from an EFI conversion - if you want EFI then buy an EFI harley as a retro fit is not as simple as one would think.

Gidday Dynoharley and Tussuck,
The carb is the one that was on the bike when I bought it and has only been cleaned out a couple of times (by a bike mechanic) as I had a rust in the tank issue which didn't become obvious for a couple of tank fills after I got her home, the only things I have done is replaced the tanks with new tanks and replaced all the fuel lines and filter/s, what makes me think it may be electrical is for those reasons alone and that it runs fine for quite a distance then shits itself after a period of time. She doesn't seem to foul plugs either we'll not lately anyhow. 
I will see if I can get a photo of the ignition system today and put it up I can't seem to get any other photographs to show other than the first pic of the carby I posted earlier to show Kiwidave. (Bloody technology).

shrekster.

I notice kiwidave said its a CV Carb ....
"starts great, idles well, runs well but when she warms up she starts coughing under any acceleration and runs crap unless at low revs"
I just holed a diaphragm in my CV and the symptoms were almost identical.

I found this quick vid pretty helpful when rebuilding my carb and the parts were a lot cheaper than a battery


http://www.youtube.com/watch?feature=player_embedded&v=iTPPP8jkje4

Gidday fellas,
And hi Drew71. We'll geez you guys are all so bloody helpfull that I don't know which way to turn now hahahaha. I really appreciate all the input I sincerely do and it has certainly opened a few avenues of inquiry to me as to what to check, I think I'll plod along and see if the electrical system might be the cause before I attack the carby as I'm no mechanic or Gynecologist for that matter that's for sure but I'll sure as he'll have a good look at it for her.
I'm still trying to sort out the bloody photos on this forum as you can see so what hope do I stand with an electrical system or a carby - FML.
Anyway as before thanks heaps fellas I will post any outcomes or developments on this thread as they happen.
Shrekster.

Gday guys i just bought a 1988 softail a few months back off a so called motorbike mechanic. a1 condition lol yes sure 

is a solid engine but was having trouble with the charging system and also a few backfiring issues ,did a bit of research and found the stator was buggered "no volts" replaced the stator and sorted the charging problem.

now 14 1/2 volts at idle. Its a bit of a job to change and if your not handy with a spanner get someone else to fix it

but still had a few idle and backfire issues ,so i pulled the carby off and waiting a rebuild kit for it.Now the point of my post is before ya take carbys off etc there is a vacuum hose that operates the voes switch which advances and retard for  the ignition system.

mine was cracked and might have been as old as the bike ,any vacuum leak will cause a mixture problem and might not be advancing the ignition when needed

cheap and easy to try that first .Hope this helps someone

Cheers n Beers 

Gidday Boney and cheers mate I will certainly put that on my check list to have a look at.
Shrek.

Gidday fellas latest developments are as follows the electrical system is fine apparently and it appears to be a carby problem so bugger me aye !!!  

Ive been told to take the carby off and either strip it and make sure it's got no sh!t in it or make sure that it has been put back together properly as it is a later model carb than the original one for the bike. I found a good bloke that used to own a motorcycle wreckers for a number of years who said he'll check it out for me if I'm not confident in doing it myself. 

Big thanks again to all of ya for the info and I'll let ya know how I get on. 

Shrek.