My old man limped into town today on his way back from Sturgis. I guess he's spent the past four days trying to get the bike running, has had a hundred different guys look at it, and gotten a hundred different opinions as to what could be causing it. I've never gotten anything but great advice from you guys, so I figured I'd toss this one out there and see what came back. A little details:

1988 FXLR Evo Lowrider (5 year limited manufacturing run)
New coil, plug wires, plugs, new top end gaskets, including heads, carb torn down and cleaned/rebuilt, new ignition "sending unit" (?), new relay box off the ignition, and other stuff.

Starts relatively fine, idles okay, (not great) can hit throttle in neutral and it sounds fine... the second you put it in gear or try to maintain speed in the lower gears, it pops, farts and misses horribly. Does the same thing while decelerating. Accelerating or idling, it seems fine (more or less). It sounds (in my limited scooter knowledge) to be the ignition module (its a dual fire) or perhaps something fuel related?? I dunno.

Guys, my dad needs this bike. He literally lives on it, and until it's back up and running he's stuck here which means he won't make it to Milwaukee for Harley's 100th. Any ideas or assistance anyone can throw out, I'd seriously appreciate it. Thanks!!

 

I don't know much about motorcycles, but if it were a truck I would suspect a timing problem. Does it backfire often?

 

Pressed on gear on the camshaft has slipped. Cam timing is retarded.
Just my 2¢

 

Thanks for the responses guys... tomorrow afternoon we're gonna do a few things with the carb, then on Monday we're gonna take it in to the local harley shop to see about checking timing on it. I have a light and everything, but from what I understand, it's not that simple on a bike. I really appreciate the ideas guys, and if anyone has anything else to throw out, keep 'em coming!

I'll keep ya posted.

 

You said it accelerates and idles fine...probalbly already checked but,

1) double check the vacuum line (VOES) running to the intake...
(stock kiehn carb or aftermarket?) I always forget to reconnect when I do carb work...gives similiar symptoms

2) double check the ground wires...(loose batt ground ?)...doubtful
3) intake leaks...maybe
4) igniton module...maybe, but doubtful
5) stator...doubtful

Usually, once the timing is set on a harley ya dont need to mess with it...unless ya did a cam swap?
To check the timing ya need a clear plug to insert in timing hole...it keeps the oil from sloshing out.

My .02

 

thanks wabiker, you're probably right on. We took it in yesterday after completely tearing apart and rebuilding the carb AGAIN, (S&S E series) and the Harley mechanic's first impression was something to do with the VOES also. He's still got the bike, so hopefully we'll hear something today. Thanks again for all the info guys!

 

...Good luck with that...Keep us posted on the results

 

need to replace the bearrings in the hamster wheel! ok seriously, i dont know anything about bikes but am anxious to hear what the problem was

 

What kind of ignition module is he using? A friend of mine put in an aftermarket module ( can't remember the brand ) and had about the same trouble. Put in a Screamin Eagle and it runs great.

 

S&S carbs are so simple they rarely hard fail, so the thing to do is run the usual checklist any shop does.
Check compression in both cylinders, even if you are "sure" you don't need to.
Check for manifold-to-head vacuum leaks, and install an all-metal manifold if not already using the nice S&S part that comes with the carb kit.
Check the grounds and inspect the wiring carefully.
Rubber-mount HDs are known for ground problems.
(Besides working on scooters I have an '88 FXR and experienced this firsthand.)
If you suspect the ignition, and want to get home ASAP, just bolt in a points kit! (Available at most shops.) You can block the VOES, disconnect the ignition module but leave it in place, and use whatever coil you have handy. Easy quick fix.
Coils fail often so always swap one in for troubleshooting.
Time it by ear (I never use timing lights on HDs) so it starts easily when warm and does not ping under load.
Note that NOBODY makes a durable mechanical advance for HDs, so while points run OK an electronic ignition is what to use long term. The nice part is that HD points are interchangeable with Chevrolet so replacements are cheap.
Hope this helps.

 

Thanks for the additional advice folks, it's sincerely appreciated. The bike's been at Dillon Brothers HD for the past two days. They're amazingly busy, so they haven't gotten it in yet. They did take a quick look earlier today, and found the regulator was bad, so they're gonna change that, but nothing definite yet. I'll keep you guys updated.

 

...Bad regulator huh...?
When mine went out, I couldnt even get the bike to start...it would crank but not fire...usually they dont "go" bad, they either work or stop working....interesting...
I hate electrical gremlins...speaking of which, with all this stuff going on with the bike dont forgot to check the battery charge/condition if its been awhile since replacement..

 

Well, so much for that. They stuck him for $200 for a new regulator because one of the wires was broken. I know for a fact it wasn't when we wheeled it in there. This friggin blows. Even if they admitted that they broke the wire, all they would've needed to do was a quick splice to repair. Instead, they got a quick $200 and didn't fix a thing. I hate mechanics.... all of 'em... Harley or otherwise. It never stinkin' fails. Mechanics are the sole reason I started learning about cars 'n trucks so I'd never have to take mine in again!

Anyways, well... we're back to square one. *sigh*

 

Post more details.
Does it run rich? Lean?
What are your cold compression readings?
(Hold throttle full open when checking, disconnect ignition coil of course)
When in doubt, hit the basics one by one., and post what ya get.
Grab a factory shop manual if you don't have one, since neither the Chilton or Haynes are adequate.

 

Okay, little update. (I'm so tired of working on this thing. I love the old man, but he's quite stubborn and daft, so he's probably not going to listen to anything said...)

We know it's not electrical. The ignition's been replaced by a Screaming Eagle, new coil, plugs, wires, all grounds checked/cleaned/greased (dielectric). Compression's fine on both cylinders (don't remember exact numbers, but rear's within 10/20lbs of front) To me, it's acting like a fuel delivery problem, so we're looking for a rebuild kit for the carb, and sometime today we're going to check the in-tank filter.

Oh yeah, we also ran a full bottle of SeaFoam threw 'er and it helped a bit, but still not right.

I'm not sure what other details I can mention, but any other questions, let me know.