Newbie question '84 Interstate fuel tank venting

[MonkeyWrench]

Hi, I signed up here a couple of weeks ago and posted about a '78 GL1000 that I was considering buying as a project, but sadly came to the conclusion that it was going to be too much work to get roadworthy. It had a single carb conversion that I was not cool with. I decided to invest a little more $$$ up front for a unit that was already roadworthy.

A couple of days ago I picked up an '84 GL1200 Interstate that I could ride home, and super happy with it so far – except that it decided to stall out and not restart, luckily at our side gate about 30 seconds after returning home. Would not fire back up. :-P

So fuel or spark ? It had run fine on the 30 minute ride home except for annoyingly low idle (set at about 250-ish) so I thought most likely fuel. Opened the fuel tank cap and it sucked enough air that I could feel it flow by my hand. It started right up after that.

So my newbie question is: At a glance it doesn't look like a vented cap ? Does the tank have a vent tube and/or some sort of breather that's obstructed somehow, if so is this a common problem w/common solution ?
It just had some fairly serious work done before I bought it (broken spark plug that couldn't be extracted, resulting in head replacement on right side.) So perhaps something got connected wrong there ?

I'm planning on sourcing a user manual and service manual ( PDF would suffice.) Previous owner says he has an owners manual that he has misplaced, so probably getting one that way eventually. In the meantime I'm a Goldwing newbie with no resources besides the interwebs.

Thanks in advance,
Al from Alberta

[ritalz]

Welcome and congrats on the purchase. The cap should be vented unless the PO sourced the wrong type of cap. Soak the cap in some cleaner for a couple of days and it should open it up. Or you could drill a tiny hole to create your own vent.

[CYBORG]

What ritalz said. Vent is a one way valve. Lets air in, but not out. As the fuel in the tank goes down, it must be replaced by air. If not the vacuum created by the fuel workes against the vacuum of the pump, until it overcomes it. Fuel stps flowing, and engine dies. As the engine cools off, the fuel cools off, and the pump can do it's job again. Can happen easier in hot weather. Drilling a hole in the cap will work, but in a turn over accident, it will allow fuel the leak from the tank at the cap. I would replace the cap with the correct one if cleaning doesn't work

[gltriker]

now, scroll down this page to Similar Topics for discussions and remedies

[MonkeyWrench]

OK thanks !

I’ll see if I can spot any insect-related issues and maybe give it a good soak for good measure. Might be a good excuse to pick up an ultrasonic cleaner ! (^_^)

I’m also going to stop by the shop that did the recent work and have a chat with them, I’d like to hear about what was done straight from the horse’s mouth. Mostly wanting to know if they put in new timing belts while they had it apart. For the cost, I sure as hell would have but… I’m not going to assume.

Thanks again !

[MonkeyWrench]

Update, three days later:

Well it seems that I jumped to the wrong conclusion. It was not the venting of the tank that let it start up again, it was the fact that the engine was totally cooled off. I have since had it out a couple more times and if it gets a decent run at highway speed that gets it right up to running temp and then it gets switched off, it will not re-start for a good 15-20 minutes.

I took it out last night for about a half hour run on the highway at 120km/hr (70-75 mph) and stopped at a roadside turnout out in the middle of nowhere for a few minutes. I was dismayed to find that once again it wouldn't start, opening the gas cap did not release negative pressure this time, and did not resolve the problem.

After sitting and cooling off for about 15-20 minutes it finally started (thank god) and got me home. Some manner of vapor lock happening I guess ? I'm thinking it's not a spark issue as it runs/idles fine when it's up to running temp, just don't f@%king shut it off !!

Wondering if anyone has run into such a situation before.

I'm guessing its recent trip to the shop did NOT include a carb clean/rebuild. I'm hoping they at least put in new timing belts...

[redglbx]

If they didn’t change the belts and not knowing how old they are it is a must do thing ! Their life is determined by age not miles and a belt failure is a catastrophic event.

On my 76 when we moved back in 98 my brother & I were going to eat in a town 50mi away, nice meal ! On the way home I swung out to pass a car and as I pulled along side the car I heard a faint ppphftt and lost power so I coasted to the side of the road. A little roadside investigation showed the left cam/ignition no longer rotated.

So I figured the motor was toast ,,, but I got lucky and just bent all the valves in the left head,, luckily they just put some smal dings in the top of the pistons, so about $400 later I had rebuilt the head and it was running again w/new belts.

So, the details are that I bought this bike brand new in October of 76,, the broken oe belt occurred in either 98 or 99 so 22 or 20yrs later,, but the bike only had 13k miles on it !!! I still have the belt and looking at it shows no evidence of wear except where it had broken, no cracking or stress is evidenced. CHANGE YOUR BELTS !

I’m getting ready to change them again which will be the third time since that day waaay back then,,, the bike is around 60k mi now, so if my back is co-operative I will change them along with some other work I’ve been putting off, the only good (?) thing is that I really haven’t been able to ride it for the last several years. Anyway that’s my belt sob story.

[CYBORG]

don't know what ign you are running, but I had a simalar problem, that was caused by a dyna ign modual getting hot and dieing. But was fine when it cooled off

[Sagebrush]

I was thinking ignition component as well.

[Track T 2411]

Iwould agree with Dean and Cyborg ...
Does it actually die, or not start after being shut off?
When you do try to start it again right away, does the starter really labor, like it's barely able to turn the engine over, or does it just seem to spin, maybe making some clunking noises?
When it dies or won't start, do you notice any other electrical issues such as lights flickering?

One quick way to check for an ignition component failure is pull a spark plug cap just loose enough to hear the spark jump the gap while cranking the engine. Cylinders one and two run on one coil, three and four, the other. You might try it once while the engine is running so can hear what it would sound like.

[MonkeyWrench]

Hi everyone,

Thanks for the input !

So FYI the GW is NOT dying when it gets hot, it will run/idle fine in that state. It's only after shutting off that it fails to re-start.

I took it out for a spin one evening, stopped and filled gas, tooled around for about 20 min. making a few stops around the neighborhood. It never failed to re-start, but the engine was barely warmed up - essentially just idled around within a mile or so from home.

Then I rode it to work and back a couple of days this week (approx 5 km/3miles of city + 15km/9miles of highway each way.)
I arrive at destination, engine is running fine – no missing, loss of power, or anything that might indicate a spark issue. When I shut it off it will not re-start until cooled off (15-20 minutes.) It is perfectly consistent in this behavior.

I will check for loss of spark when hot Cyborg, Dean - thanks for the tip. I’m starting to look into sourcing a vacuum gauge, bits & pieces needed for carb sync so as to be ready for carb rebuilds if it comes down to that.

I'll be digging into this further as soon as I have time but I'm a little busy with other family/work stuff just now. I've decided to keep it parked for now as it's not a pleasant prospect that if I happen to carelessly stall it out somewhere, I'd be stuck there for a while. Not the worst thing ever I suppose, as it has always re-started after cooling. Until it doesn’t….

I do appreciate your concern redglbx but just so you know, you are preaching to the choir here about the belts !! I will definitely pull the covers and have a look at them. I’m told that the engine work was completed just before purchase so it should be very obvious at a glance if they were changed at that time or not. Unless they are obviously brand new I will absolutely change them myself. Seems like the PO is a pretty decent fellow and took pretty good care of the unit, says he's owned it for more than 25 years and decided to sell it after purchasing a much newer H-D. But he seems to be dodging my request for a copy of the shop's invoice for the recent work, I suspect that it was an off-the-books "cash" job, and he doesn't want to admit it. As it happens the two guys running the shop are both off on vacation until later this month, I intend to pay them a visit for a firsthand chat as soon as they’re back.

Also replying to Track T – As mentioned above, no it doesn’t die on its own when hot. When trying to re-start, no apparent issues with the starter, it engages perfectly and gives the engine a good strong crank. Not seeing any flickering lights etc. so in general I would have to say no such obvious indications of electrical problems. I haven’t tried a load test on the battery but it seems good and strong, looks quite new.

[redglbx]

Monkey, sounds like you have a bad ignition pickup or the little modules (my pick) but I guess I’d start with chasing the wiring making sure the connections are clean and secure. If that is good then I’d move to the ignition modules. But if you get it hot and you get the “no start” condition check for no spark first.

Update: looking at the ignition diagram on Partzilla shows that your wing doesn’t use the little ignition modules that thought might be the problem but instead uses a single ignition module (pn 30400-MG9-005) which would explain no spark on all cylinders vs the little ignition modules that I originally thought which control 2 cylinders each. Unfortunately none of them are available at Partzilla. Again this would be a no-spark condition when hot.

[MonkeyWrench]

Oh and one more thing...

I've started looking on Ebay etc for physical copy of an owners manual, would also like a genuine Honda shop manual if I can get one. In the meantime if anyone has a suggestion for where I might download PDF copies for the short term, it would be much appreciated. I did a google search and found some sites that are *selling* downloadable copies but the sites seem a bit sketchy and I'm a little leery about whether I would actually get what I pay for ?!?

Maybe I should update the subject line on this post ? I guess I'm wandering a ways off the subject of gas cap venting !!

[MonkeyWrench]

Monkey, sounds like you have a bad ignition pickup or the little modules (my pick) but I guess I’d start with chasing the wiring making sure the connections are clean and secure. If that is good then I’d move to the ignition modules. But if you get it hot and you get the “no start” condition check for no spark first.

Update: looking at the ignition diagram on Partzilla shows that your wing doesn’t use the little ignition modules that thought might be the problem but instead uses a single ignition module (pn 30400-MG9-005) which would explain no spark on all cylinders vs the little ignition modules that I originally thought which control 2 cylinders each. Unfortunately none of them are available at Partzilla. Again this would be a no-spark condition when hot.

I really appreciate everyone here taking time to offer suggestions, I will definitely follow all these leads. Certainly my current lack of experience with the GW engine & associated systems is not helping, but I'm sure I'll get there! My only point of skepticism ( for lack of a better word ?? ) regarding the spark suggestions is the fact that it doesn't die on its own when hot, that it continues to run fine until it's shut off.

I suppose if some component of the ignition system is being affected by the heat such that the spark gets weak, but is still there, that might explain it ? It could have a weak spark that is able to keep the engine running, but not enough oomph to get it started back up again? But I'd expect to start noticing some loss of power if the spark is getting weak, which I have not.

Anyway sorry this is kinda pointless speculation, better to just start digging into it and troubleshooting, but still tied up/busy with other things. I will update when I have more info.

Thanks again !

[CYBORG]

thought about the ign sw.? I've seen a probpem that when turning the sw. off, the engine would not die. Perhaps when you turn it back on. a bad sw connection won't let it start. Try turninging if off and on a few times, and see if it starts. who knows, and it doesn't cost anything