Bike Dies

[Mroadrunner3]

ok here we go again, "78xs1100f, got the bike last year, rode most of the summer after putting it back together, had to put used set of carbs on it because the ones that came on the bike were rotted out. only did a basic clean befor i installed them. now this year, got the bike out of storage, fired right up. i did have new carb kits on hand but was gona wate a few weeks, the bike changed my mind only after 2 trips of about 20miles each. removed and cleaned the carbs, instlled original kits as per the spects i have from the manual. did all the pre adjusting and installed back on bike, got all lines fuel and vac hooked up no kinks, cleaned out the tank screens, checkd fuel flow good to start. runs way better than it had befor, ok here is the problem, after only about 10 to 15 mins of idleing it quits, will want to restart but wont till it sets for a few min 3 to 5min. will run another 10 to 15 min,acts like its running out of fuel but as i said the lines are ok, the pet cocks are working as thay are supose to, there is NO SPIDER in the works was never on the bike when i got. so fuel runs from tank to carbs one side feeds 2 carbs each. was wondering about tweeking the floots to let a bit more fuel flow into the carbs.
any other ideas would be grate

[TopCatGr58]

Hey RoadRunner,

Your Profile says the proper 78E model, but your post says "F"....think it was a TYPO! The "E" didn't have the Spider/Octopus, it uses vac. controlled petcocks! There is a small nipple on the front/forward end of the petcocks where a vac. hose connects to one of the Intake Boot Nipples on both sides. There is a PRIME function on the petcocks, so you can switch it to that to see if it will keep running after the 15 minutes? If you're just idling, doubt that it's getting that hot, but a fan blowing on it wouldn't hurt! Also, possible clogged gas tank cap vent, can pop the cap to see if that helps also.

Also, with it idling, it's not charging very well, and IF you have a weak battery, could be draining it down to close to the low voltage limit for the TCI...10.5 volts? JAT? Have you checked the charging system? How old is the battery.

T.C.

[Mroadrunner3]

your right it was a typo, did all the tank isues, cap, i did pop the cap and it still only runs for about the 10 to 15 min, the bike did sit all winter, the battery was new last fall, but no i didt check the charging voltage, i have always ran the bike on the prime position, i do turn it off every time i park it. i dont think its getting hot eather its been real cool here. I will check the charging tomaro never thought about a low volt problem, as soon as i get it to run more than 15 min i can cynk the carbs,

thanks TOP CAT

[WMarshy]

How new is the fuel, did you put in new fuel to start it the first time this year? Was it stored with fuel in the carbs and tank over winter? How does it run in those first few minutes, smooth or rough? When its idling have you tried to give it throttle, does it bog or pop, or rev nice and smooth?

[TopCatGr58]

Hey Again,

Marshy has some good points also. If you didn't put any fuel stabilizer in it, the fuel looses 1 octane point every month, and once it gets down to near 80 or so, it doesn't work, or at least not in our machines very well!!

I essentially killed my battery this past winter by also not tending to it like I should have when it was stored for the winter, and several cells plates got exposed due to considerable evaporation!

A new battery made a nice change to how quickly and strongly it now starts!
T.C.

[Ken Talbot]

Your post reads to me like you're only one cleaning into the triple carb clean sequence. It sems like it runs for a bit on a set of full float bowls, then runs out of gas when the bowls are not refilling properly. I would look closely at the screens above the float valves, and make sure there are no kinks in the fuel lines.

BTW, the petcocks on a '78 Standard do not have an "off" position.

[WMarshy]

I agree with Ken, define a "basic clean"... taking the bowls off and hitting the floats and jets with some carb cleaner might give the impression that they are clean, but its not. Anything that might seem like a short cut never is. "Warnging: Full disassembly required."

[oldyam80sg]

With the bike running spritz the pipes with water to see if they sizzle.If they don't something else is happening.Like mentioned before, the carbs need more than just hitting it with carb cleaner.I took the float pins out and pulled the needle valves(think that is what they are called)-screens were full of crud-that will definitely stop fuel flow.Also you might want to install inline fuel filters to catch crud before it enters carbs.

[Mroadrunner3]

i should define basic clean, should have said major, the carbs were taken down as far as they would go short of splitting them apart, the screens in the floot neddles were cleaned, and check for blockage. the bike was stored with fresh fuel and stabilizer, and the carbs fogged. i had the carb kits on hand but was gona wate for a few weeks till it got a little warmer. but as i said the bike changed my mind. the bike runs real nice and smooth, no poping and all exhaust pipes are hot. and with the new carb kits i drained the older fuel out cleaned the tank screens and addded new fuel. during the cleaning the cross over tubes were clean, as i said all but splitting the carbs apart, but the tubes were blown out using low pressure air. from the carb side and the cross over tube. did do what top cat sugested, checked battery was at 12.5 at no start and running with some throttle was 13.7. got all back together and tried again, same thing but this time it ran for about 100 yrds and dies. so the push home was not all that far, got it home pulled plugs and none would fire, so that ledd me to the TCI, so i tried a little love tapping and the bike would fire and than not. ever heard of tunnal vision, well i must have a bad case of it, i keep thinking it was a fuel problem because thats how it started out, have new box on order. i want to thank all for your imputs. i will keep you posted as soon as i get new box. again thanks all.

[bikerphil]

Had a similar problem, bike would run fine, then just die. Sometimes it would start right back up, sometimes it wouldn't. I traced the problem down, it was bad pick up coil wires.

[randy]

pulled plugs and none would fire, so that ledd me to the TCI, so i tried a little love tapping and the bike would fire and than not.

Have you re-soldered the connector pins inside the TCI? That cures 90% of TCI issues.

[TopCatGr58]

Hey Road,

Sorry you jumped the gun and went ahead and found/ordered a replacement TCI! As Randy posted, he's the TCI guru that actually repairs them. Check out his web site linked from his username, and you'll find info about Resweating/soldering the connections. That might get it working, and then you'll at least have a working SPARE!

Another weak link is the ballast resistor, can get cracked, and when it heats up, spreads apart and no more power to the ignition coils! You can bypass the plug to the B.R. by just unplugging it from the BR and plugging the wire harness ends together for a test. If the bike runs longer, like 5-10 minutes or such, then you may have found the other possible problem, then just replace the B.R.. It'll burn up the OEM coils if you run it very long bypassed!

T.C.

[Mroadrunner3]

Not a bad idea ill check the BR just in case and make sure its not bad, not sure if thats avail after market, i rember that the old old dodges had one mounted on the fire wall and when it went bad the car would not start does any one think that may be a good replacement. its only about 2.5 in long and aprox 1/2 wide. its been a long time sence i had to solder some connections on a ckt card, i know i can get what's called a track kit and replace burnt or broken tracks on the card.

[mperes01]

Gas Tank Cap

I know this is an old post but I have something that may be of help.

I had this same issue shortly after replacing the gas tank lid on my 80 special. The problem only showed up about 10 minutes after filling the tank. For no reason the bike would die. I noticed that if I opened the gas tank lid and re-closed it, the bike would start and run without issue. It turned out that the rubber gasket created a tight seal and the vent holes were clogged. The tank was in a vacuum state and fuel would not flow to the carbs. The fix was so simple. With the tank lid open, I rotated the gasket and cap about a quarter turn. The problem never returned.