Why would it die?

[ridinghard]

Hey all, I am new here and there may be another post about this but I can't find it so if there is another post please send me to it.
I have a 1980 XS 1100 Special I just bought a few months ago. I test drove it and it ran great! I drove it home (the long way of course). After about 50 miles it felt like it may be out of gas the way it bogged down, but all I had to do was pull in the clutch and let it idle down. I let go of the clutch and it came back to life. The next few times I rode it I got a similar occurrence. The more I rode the more it happened and the worse it got but it only happened after a 10 to 20 mile trip. Anything shorter than that and it rode smooth. I took advice and cleaned the carbs (5 times now) replaced the in line filters and petcock filters, cleaned the tank to ensure no more particles could get in the system, and it still does it. Now it actually dies when I pull in the clutch and it back fires real bad. It always starts great but once it rides for about 10 miles it starts doing it. I don't want to spend over $200 on ignition coils and find out it isn't the right fix again.
Any ideas on figuring this one out?

[randy]

There is a vent in the tank cap, you'll have to remove the cap to take it apart. Chances are the vent hole is clogged.

You can do a quick test by opening the cap when the trouble shows up, if the trouble goes away, then you've nailed it.

[TopCatGr58]

Hey RidingHard,

Yea, a clogged tank cap can cause a lack of fuel flow due to a vacuum lock so to speak, but you didn't mention whether you still had the Octy or not? If so...switch the petcocks to PRIME, and see if that fixes it. IF so, then the Octy isn't working right, and most folks find it easier to remove and just remember to turn OFF the petcocks when parked, vs. trying to fix it with a rebuild kit that regrettably has the wrong sized piston on the replacement diaphragm, and often doesn't work to shut OFF the fuel when the engine is OFF!
T.C.

[edavi394]

It is Probably the vent in the tank cap as stated but i did have a xs750 for a while that did almost the exact same thing and it turned out to be a electrical problem took for ever to find it but once I did I never had problems with that bike again

[ridinghard]

I tried putting the petcocks on prime and it still did it but I took the octopus off any way to see if it helped. I do still have it. I'll try the gas cap tomorrow and post the outcome.

[melbxs]

Coils and leads from MIKESXS will only cost you about 80 bucks. Seriously do it. I had exactly the problem you describe and new coils were the best money I ever spent.

Your coils and leads are ancient. They cannot be any good after 30 yrs.

Replace em.

I am a coil nazi. I wouldnt help anyone work on a problem bike if they hadnt already changed 30 yr old coils and ht leads.

[trbig]

Your coils and leads are ancient. They cannot be any good after 30 yrs.

Hmmmm... And here I was thinking my bike ran pretty dang good on the original ALMOST 30 year old coils.

I understand changing coils if there's a problem with them, or you're just trying to find a H/P or two more... but I'm no fan of fixing stuff that isn't broke. Forcing someone to spend money they don't need to before you'd even help them... well... I guess Nazi is a good word.

I'm glad they can come here for help then.


Tod

[79XS11F]

GG . I guess that makes me a "beer" Nazi. I refuse to work on any bike that does not have a fresh supply of beer. I don't like the 30 year old stuff :-)
Rob

[olebiker]

Originally posted by 79XS11F
GG . I guess that makes me a "beer" Nazi. I refuse to work on any bike that does not have a fresh supply of beer. I don't like the 30 year old stuff :-)
Rob

What about the recycled stuff Rob?

[Tusler]

Just a thought, backfire is caused when the combustion is not happening at the right time, like a valve is open or the timing has move- which is unlikely, your best bet is to go after the coils, wires and or plugs cause if they mess up when they get hot - common for old ones - the spark can hit at the wrong time causing your symptoms.

[melbxs]

Originally posted by trbig


Hmmmm... And here I was thinking my bike ran pretty dang good on the original ALMOST 30 year old coils.

I understand changing coils if there's a problem with them, or you're just trying to find a H/P or two more... but I'm no fan of fixing stuff that isn't broke. Forcing someone to spend money they don't need to before you'd even help them... well... I guess Nazi is a good word.

I'm glad they can come here for help then.


Tod

Yeah - good point except we're not talking about your bike - we're talking about his. His bike exhibits all the signs of knackered coils and/or leads and the quickest and easiest thing to do is spend a paltry 80 bucks on coils and leads because in a very high percentage of cases this will be his problem.

He's already ripped out his carbs on somebodies advice (how helpful was that?) - I know they are troublesome at times but going to those lengths before changing the 30 yr old coils and leads (a 2 hour job) is IMHO madness.

My reply might have been a bit "in your face", but it makes a lot more sense than tearing your carbs apart.

[ridinghard]

I looked at Mikesxs and only found coils for a 650, nothing showing for a 1100. Not that I have over looked things or searched wrong before....... I'll look again.

[melbxs]

Same coils.

TopCat wrote a superb rundown on them here:

[thewiz]

Ahhhh, (belch) ... a man after my own heart, Rob

..... "beer" Nazi. I refuse to work on any bike that does not have a fresh supply of beer....

[Dennyz]

I hate to see parts shot gunning. It is an awful expensive way to find an inexpensive problem. While it is possible the coils could be the problem, it is very unlikely both are bad.

There are a number of possibilities that could cause this problem. Give these a try before dumping big $$ on coils. I am sure there are other suggestion that chould help.

first check to see if you have any colder( or cooler) exhaust tubes. This should be one of the first places to check. It can give an insight to fuel or electrical.

Clogged tank vent - ride with cap unlatched and see the problem persists. I know, I know, it is a bit risky, but hey, we are trouble shooting here.

Bad Octopus - run on 'prime' or completely bypass Octo with fuel line.

Stator coil (and/or Rectifier) - I just got bit by this one. has the same symptoms as running out of gas. It heats up and shorts the electrical to ground. Unplug the stator coil and see the problem persists (must have a good battery).

Pick-up coils - These are a pain to trouble shoot and typically don't behave like this problem. But don't rule the out.

Bad solenoid - heats up and drops voltage to the TCI. Run jumper wire from battery to TCI.

Bad wire connector somewhere - same as above (jumper wire).

Bad kill switch - same as above(jumper wire).

FYI - trouble shooting is an art. It is like playing Master Mind. Change only one things at a time. keep a log. be patient. The biggest problem with trouble shooting is introducing a new problem and sending you down a wrong path. Trouble shooting is about chasing symptoms. If a symptom changes while trouble shooting, back up. This is the first warning that a new problem may have been introduced. And, always keep in mind that you could actually have more than one problem (especially on a new bike).

Most importantly - Don't give up! take a big breath, have a beer, talk to us. tell us what you have tried. A fresh point of view is a valuable source to even the most experience.