Fuel Issue??? Help!

[iowasculptor]

I'm new here, and a new K-Bike rider.  I've been riding my 1985 K100RT with 72,000mi, for a couple months with no complaints or worries, but... the other day after riding, I filled it up, put some sea foam in it and I parked it in the garage, it sat for a few days while I was out of town.  When I came back I got it out to ride and tried to start it and it would chug chug and die, If I give it throttle it dies.  If I twist the throttle then start it with it wide open I might get it to rev, but it will soon chug down and die, sometimes it doesn't rev, I can't keep the revs up either, if it tries its very spastic its revving... This all happened out of the blue.
I have three thoughts but don't know where to begin:

1)  Fuel system
        fuel pump
        fuel filter
        Injectors

2)  Vacuum leak (I have no idea where to start looking though)

3)  Electrical malfunction of some kind (no idea of where to look)

If anyone has any ideas, I would greatly appreciate it, I miss riding my bike
Matt
 

[Laitch]

If anyone has any ideas, I would greatly appreciate it, I miss riding my bike

:laughing-on-ground:
There are 61,000 posts on this forum, Matt. Quite a few of them contain ideas about why K-bikes don't start.

First, explain exactly how long you've had the bike, how many miles you've logged on it and what maintenance you've done on it already. Next, explain why you put Techron in it when it had been running perfectly well. Have a look at this to get an overview of what you're riding.

Next, tighten your battery connections if they're loose. Check, or get checked, the output of your battery to be sure it's not below 12 volts.

Now, use this post to check and clean a connector under the tank. On your bike you may find it on the left side rather than the right side. After that check the main plug under the seat to be sure it is tightly connected. Then look at this guide. Finally, familiarize yourself with this section.

Instructions for vacuum leak diagnosis, fuel filter changing, selecting an appropriate firearm, and using brute force are covered in many posts on this forum.

Good luck!

[iowasculptor]

Thanks for the links Laitch,
I've had this bike for about 2 months, I have the receipts from the previous owner going back at least 9 years with all the regular maintenance.  He got sick last fall and had to quit riding it so it sat over the winter and spring.  He replaced the battery on 6/03/2016 so its a new battery.  Other wise the maintenance was up to date from the receipts, oil, spline, tires, etc...  I put the sea foam in it just to try to clean out anything from it having sat for that time, there were a couple times that for a very short amount of time it seemed a little off, it cleared up but just wanted to make sure things were clean.
Matt 

[Laitch]

. . .  but just wanted to make sure things were clean.
Matt

A better way to determine the state of the fuel system is to remove the fuel from the tank, carefully remove the cap assembly and take a look inside. If there are deposits in the tank, you'll need to clean it, and maybe replace the fuel lines for good measure. Large chunks of degraded rubber don't get "cleaned out" by chemical treatments. They get dislodged to dam up the flow somewhere.

A "new" battery may be a defective battery, too. Checking the output is good practice.

The links give you plenty to go on, especially the ones concerning checking the tank plug and electronic control plug. The hardest tasks for many of us is getting started with diagnosis and avoiding theorizing or presuming anything.

[Martin]

Techron does no harm, however I don't know what effect Seafoam left sitting would do. As the bike was running fine before you added the Seafoam, I would drain and flush the tank replace all the hoses and filter.  I would probably also clean the injectors, there are sites on how to clean them.
Regards Martin

[Laitch]

Techron does no harm, however I don't know what effect Seafoam left sitting would do.

I should have written "SnakeFoam" or "SeaOil"—whatever those two products were that Kennybobby doesn't seem to admire. :hehehe  Anyway, they all harken back to JC Whitney's Ring Job-In-A-Can, Motor Honey and the late Reverend Ike's Sanctified Prayer Cloths.

[Martin]

Laitch fortunately we don't have Snake foam or Miracle sea oil in OZ. And generally I have found most additives to be of dubious value. However Techron does seem to work or it could be wishful thinking, or possibly something from the sixties. :dunno
Regards Martin.

[Laitch]

However Techron does seem to work or it could be wishful thinking, or possibly something from the sixties. :dunno

Well, johnny uses it regularly in his bike which takes his thrashings gracefully so that's a convincing testimonial. I'm just not as considerate when it comes to my bike. Regardless, it seems to worship me.

[Mike Flores]

Since the bike starts and idles, and only dies when you try to give it throttle, my guess is that it's a fuel flow issue. I bet your in tank fuel filter is plugged up. Like what's been said before, drain the tank of it's fuel, clean it out, and replace the fuel filter and check the status of the fuel lines... probably a good idea to replace them too. Cleaning the injectors certainly wouldn't hurt.

[kennybobby]

check all the fuses, but especially #6 for the fuel pump (1 is at top, 7 is at bottom), it's not clear if you're saying that it's really starting but won't take throttle, or not starting.

snake foam (sea oil) msds

pale oil   40-60%   (diesel fuel)
naptha   25-35%   (coleman lantern fuel, or gasoline)
IPA      10-20%   (Isopropyl alcohol + water, Isopropanol)

i'd rather have pure gas in my tank, alky hawl is fer drinkin'

When you drain the tank, catch the contents in a separate jug and see what's growing or crawling around at the bottom of the tank:

[bizzaro]

There is speculation that Sea Foam has ethanol in it which can attract water.  Now on the other hand, I use Techron, and it is great voodoo magic for me.  I don't see how the comparison to a fuel system cleaner, and an engine oil additive for low compression equate Laitch.................Totally different products and outcomes

[Chaos]

probably worth pulling the plugs, see of they're fouled or wet. 

[TrueAce]

Sounds like fuel flow to me,too. Check to hear the fuel pump is running. If it's not, then check the battery voltage and the under-tank 4-pin connector Laitch mentioned. If the pump still isn't running, then you've got to get into the tank. But before everything, why don't you put in fresh fuel while you are doing your diagnostics?

[Motorhobo]

Since the bike starts and idles, and only dies when you try to give it throttle, my guess is that it's a fuel flow issue. I bet your in tank fuel filter is plugged up. Like what's been said before, drain the tank of it's fuel, clean it out, and replace the fuel filter and check the status of the fuel lines... probably a good idea to replace them too. Cleaning the injectors certainly wouldn't hurt.

Having had exactly this problem before, I'd go with Mike -- first, pull the fuel filter and blow through it. If it's at all constricted replace it. Especially considering the Seafoam thing. If anything got dislodged, that's probably where it would end up.

[Scott_]

My question to OP, how much seafoam did you put in the tank. If you used the whole can, that's probably too much.
I've used seafoam myself with both of my LT's but I only used 1/4-1/3 can to full tank.

I'd drain the tank as others have mentioned and replace the filter, then get yourself some fresh gas(without ethanol) and see how it runs.

[obsessed]

My question to OP, how much seafoam did you put in the tank. If you used the whole can, that's probably too much.
I've used seafoam myself with both of my LT's but I only used 1/4-1/3 can to full tank.

I'm not sure if seafoam alone would cause problems.  I say this because the prior owner of my K75 said he put two full cans of seafoam in the bike just before I purchased it.  Maybe I just got lucky, but I haven't had any problems ... several thousand miles later. 

[Laitch]

I say this because the prior owner of my K75 said he put two full cans of seafoam in the bike just before I purchased it.  Maybe I just got lucky. . .

Maybe he was just telling you what he thought you might like hearing.

[obsessed]

Maybe he was just telling you what he thought you might like hearing.

Not sure why anyone would think two cans of seafoam is a good thing though...

[Laitch]

Not sure why anyone would think two cans of seafoam is a good thing though...

Maybe he's from the one beer is healthy, two six packs is a spa treatment school. You weren't put off by it, anyway. In the unlikely event that you have nothing better to do, call him up, ask him and share the answer with posterity. :giggles

[jjs1234]

my 2c:

Seafoam may have disloged crap/dissolved crap when left in the tank. You should run it w/o letting it sit. I would drain the tank put new gas in.