Hi all I just found this wonderful site/forum and thought you guys could help me with my motorcycle troubles. I was reading through the most recent topics and found some similar problems, but I didn't want to thread jack from them. Either way here is my problem. In August of '09 my 86 Interceptor started leaking gas from the petcock. I took it in to my local bike shop and they replaced it and cleaned the carbs etc. Well everything was running nice on the ride home for the first mile and I was perfectly happy. Then out of nowhere she died on me on the freeway. Well that wasn't anything big it was just out of gas (I should have checked the tank but I figured they had left enough gas to at least get the ten miles back to my house). Anyway someone came with some gas and we put about a gallon in and I got home with no problems. Well 2 weeks later I got back on her and took her to work. She started up fine and everything was going well until about ten minutes into the ride. Then the bike started losing power and I would have to keep on the throttle just to keep the bike alive. If I didn't stay on the throttle the bike would just die. Either way I got to work and was worried most of the day and asked a few guys that are more mechanically inclined then I am to take a look after work. Well when they did, it started up perfect and ran fine when they got on and road it. They had no answers and I ended up just going home and the same thing happened. I wanted to get it fixed but I didn't have a ton of money and I just let it sit in my garage (stupid on my behalf). Well now in late February I'm ready to get her up and running. I have about a half a tank of gas that I never ran out and has been sitting since August. That is my first mistake and not my only one. Now the bike starts up but struggles to keep going. I ran it for about 10 minutes with the choke on and was working it back up to idling with the choke off but gave up because someone on the first floor of my aparment complex didn't apreciate the noise in the underground parking. Needles to say my battery is now dead and being tendered. I also noticed when I took my seat off and my fairings that the coolant was empty. After that long post my question to you guys is: What do you think my main problem is? Carbs? Petcock? Coolant? I'm not mechanically inclined in the least and appreciate any and all the help you guys can give me. Thanks in advance.
I really hope the carbs aren't in need of a cleaning seeing as the place I took it too cleaned them 2 weeks before this started. I certainly hope it is something as easy as overheating. You would think by filling the coolant up I would be good to go correct? What kind of coolant would I use in my bike by the way? Either way when the battery is fully charged I will have to give this all another try. It's tough though in the underground parking with the constant snow that keeps on falling. Thanks again for the suggestions and the welcome!
Bump. Anyone have any other ideas that I can check? In the other overheating after 10 minutes thread you guys seem to think it could be the fuel lines? When I ran the tank empty could the lines have gotten clogged with sediment at the bottom of the tank? Also what is the best type of coolant to use in this bike? Thanks!
someone might have a better answer but in an '80's vintage I would be fine running an all purpose coolant from NAPA. The overflow is under the tank, the radiator cap is up in the front left, hope you at least had some coolant in there. If you aren't very comfortable with your mechanical skills, I think you're going to come up against your knowledge and comfort level pretty quick on this one. Provided you weren't overheating the thing and causing mechanical problems, you could either pick the ignition system or fuel system to troubleshoot. If you ran it out of coolant and there wasn't anything in the radiator, best start with a compression test. As I said in other posts, it's a simple test that elimanates a lot of possibilities. You don't often find a problem there, but at least you know what you're dealing with (i.e. a mechanically sound engine with the primary and most basic element required for proper combustion.) My first stop on this one based on the troubles in the parking garage would be the fuel system. You'd check for ample fuel flow to the carbs by removing the fuel line. Next I'd check for able fuel flow to each carb by cracking the drain screw on the bottom of each float. If all that checks out, it's remove the carbs baby.
Thanks for the info tinkerin. I charged the battery up yesterday and the bike started up relatively easily. There is more of a problem just trying to keep the bike going. I have to keep the choke on fully at first just to get around 1200 rpm idle. About a minute in the bike realizes the choke is fully on and then starts taking off into the 4,000 - 5,000 range. I'm guessing this has something to do with the gas sitting in the tank from the summer and going bad? Either way I think my best bet is to drain the tank and then work on the trouble shooting suggested, unless the gas can be used since it has only sat since the end of summer?
I don't think this is your problem. Since the VF carbs use a fuel bypass (effectively dumping in more fuel) instead of butterfly valves (cutting off air flow) to enrich the mixture when cold, I would expect this behavior. IIRC this is what my VF500 does (it's been a few months since she's been started). It sounds to me like the bike is being starved of fuel once it has really warmed up but I don't know what would be causing this. Check fuel flow to the carbs. It may be possible that you have some blockage that is preventing them from filling fast enough. -Jake
That first time you left the shop and ran out of fuel......you sucked rust, dirt, water, whatever was scumming up the bottom of the fuel tank into your carbs. Now the small filters located above each float needle seat are clogged with debris and need cleaning, along with the idle jets. Remove the fuel tank from the bike, shake it vigorously and drain leftover fuel into a can where you will see evidence of whatever junk is still in there. Coolant: refill at both the radiator cap and overflow bottle and watch level in bottle to check for any loss.
Sounds like a classic case of a bad pulse generator. That's normally how they operate when they are just starting to fail. They get heat soaked which takes at least a couple of miles of riding to do. This will progressively get worse to the point where it will behave like that even when cold. Get yourself a voltmeter and Honda manual. Identify the harness plugs where you check the pulse generator resistance. Ride the bike around until it starts acting up. While it's still running poorly, shut it off and check the pulse generators right away. I'll be you find one of them is either out of spec or right at the limit. If nothing else, it's a relatively simple and free check. Good luck!
The lower idle at startup with the choke fully on is because it isn't running on all 4 cylinders. You can prove this by starting the bike while it's stone cold. Quickly place a finger on each header pipe and you'll bet money you'll feel 2 header pipes that are hot and two that are cold. Once the idle jumps up, that's because the engine has warmed up enough that the two cylinders that weren't firing on a normal fuel mixture, finally starts to atomize the fuel properly and combust. When the idle jumps up, you'll feel the other header pipes heat up within seconds. This happens because the choke circuit or enrichement system runs off seperate fuel pickup tubes in the float bowls and seperate passages in the carbs. They will clog up in certian one carb and not another. I'll bet money and it's an easy check because all you need is a finger. It's not the same issue as the bike dying on the highway except that it points to possible gunk in the carbs plugging both the inrichment circuit and the main jet circuit.
Thanks everyone for all the great info and help. It is a lot to take in but I will have to troubleshoot all of the possible problems and solutions everyone has stated. I will start with the easy finger test and work my way out from there. If the finger test is proven I'm guessing that means the carbs need cleaning then? I figured this was one of the main problems but I thought I would check to see if it was something bigger. I hope it is not a bad pulse generator because that seems way out of my league to figure out. Either way I think my best bet is to just clean everything and winterize it now: Change oil / coolant / drain the fuel / clean the carbs. That way by spring time my bike will be atleast to a point where everything has started fresh and should be ready to go. Unless of course it is the pulse generator. Then it looks like I will be going back to the shop. Thanks again for all the help and I will keep you guys posted with my progress. Of course if you have any other suggestions just let me know!
Well, it doesn't really prove anything other than whether you are running on all 4 cylinders at startup. The most likely cause if it isn't running on all 4 is that the choke circuit in the carbs for the cylinders that aren't firing initially are plugged. The enrichment circuit of the carbs is different than the idle and main jet circuit of the carbs. So, if the enrichment circuit is plugged in a carb or two, that is not related to your original complaint: However, if more crap from your tank found its way down into the carbs, either the filter screens above the needle/seat or down into the bowl, dirty carbs could be causing both off your problems.
TRY OPENING THE GAS CAP WHEN IT STARTS TO BOG, AS LONG AS IT HAS SAT YOUR GAS CAP VENT MAY BE PLUGGED. iF WHEN YOU OPEN THE TANK (AFTER IT STARTS BOGGING) YOU HEAR A SOUND LIKE BREAKING A VACUMN SEAL..... SPISSH, LOOK CLOSLEY AT THE GAS CAP, FIND THE LITTLE HOLE (BOTH SIDES) AND POKE IT OUT WITH A PIN. i HAD A SIMILIAR PROBLEM WITH MY OLD GUZZI, AND THAT TURNED OUT TO BE THE CULPRIT.
