1984 Honda Interceptor vf500f

I'm glad you haven't listened to these haters and still have chosen to dive into fixing this bike! I think you'll find it to be a terrific motorcycle that will offer years of enjoyment. Keep up the good work!

 

Thanks for the encouragement! I think they're awesome looking bikes.
It turns out it was my stupid mistake. I took the tank off and set it on a couple sawhorses. So that means the front of the tank was lower than the rear so it wasn't getting fuel. Propped the front up and it runs great.

 

Glad to hear that you are making good progress!

 

Great work dustin!

 

Good Luck!

GL with the fix!

I purchased a similar mileage bike almost 2 years ago. I'd say I got about 1 full season out of it before things started failing and now I spend most of my 'moto-time' wrenching unfortunately. I probably should have posted up a thread like this haha

Anyway, Good Luck and prepare to live on fleabay for parts!

P

 

I finished my MSF course this weekend and I'm hoping to get some riding in this week. It seems like when I start the bike (with the choke on ), it is only running on two cylinders (the back two). It seems to take between 5 and 10 minutes of idling before it will run with the choke off and then it sounds and feels like all four cylinders are firing. Where do I start with this problem?

 

Could be that your front plugs are fouled and not sparkin till they get hot.

 

They don't look fouled.
It seems like the cylinders get warm in order. (1, 2, 3, 4) The left rear cylinder gets warm first, which happens to correspond to the farthest left carb (where the fuel inlet is), so it's almost like the fuel is being restricted as it goes through the carbs. Does that sound right? Did I just not do a good enough cleaning job? It seems logical, but it seems to run alright after it is warmed up. All cylinders are firing also.

 

Interesting observation. Have you checked the fuel pump? Flow rate from the petcock?

 

If interested, a great tech book on rebuilding V4 carburetors is published by Mike Nixon. Really a must have for the library shelf for those owners taking on this work, IMHO.

The Motorcycle Project Book Nook

 

I made sure fuel was coming out of the fuel pump, and it "looked" sufficient to me, but I have no way to measure if it is. I basically rode it for the first time today. About 10 miles. It runs fine when it is warmed up. Is that just something common with the engines/carbs? Or should I just see if it works its way out of it with some riding, fresh gas, and Seafoam?

 

You mentioned that you cleaned the carburetors but you were not sure if you did a thorough enough job. If I could ask, how did you go about cleaning & inspecting the carb circuits?

My recommendation is to pull the carbs and carefully inspect all the circuits. While you are there, I would recommend removing the cam covers and inspecting the valve train and checking the valve lash.

 

what you've got going on sounds like what I HAD going on last week and before. It seems like it's fine, but sometimes dies for no good reason, or won't maintain low rpms for very long, yes?

In my case it was the fuel pump. Mine looked like there was sufficient flow as well, but then there were a few times when out riding it would die like it was out of gas. It idled beautifully otherwise. As it turns out, it appears that the fuel pump was overriding the vacuum line to the head and intermittently shutting fuel flow off. Same fuel pump since 1984, it had a good run.

I took my fuel pump out on sunday, it's pretty easy to do if you're not interested in losing the vacuum line at the same time (I wasn't- vac was acting okay otherwise): unplug the fuel pump, take the lines from the pump to the carb off, 1/2 of the line from the fuel pump to the petcock.. then route the remaining 1/2 line from the petcock to the carb.

If you want to take it a step further, I know Jamie has something on his site about modifying the petcock to be gravity only, doing away with vacuum altogether. I'm happy with extracting only one layer of complexity at the moment.

 

That does sound very similar to what happens to me. It has died on me twice during the 30 miles I have put on it. Once while I was downshifting before a turn, and another when I was sitting at a stop sign. I didn't quite follow what you were saying though. Could you try to explain that again?

I have noticed a small spot of oil underneath the bike since I've had it. (1-3" in diameter) Tonight I took the left side cover off (hydraulic clutch cover, behind gear shift lever) and discovered that it was coming from around the rod that sticks out of the case. When the bike is running and I push the lever off to the side, fluid squirts out. That probably means the oil seal is bad right? And you can't replace it without splitting the case? Is there anything I can do about this? It's not leaking a whole lot, it's just kind of annoying.

 

That does sound like the oil seal for the pushrod. I haven't had to replace mine (yet), but check some parts fiches at cheacycleparts or bikebandit or cmsnl and see if it's still available. At the very least, cmsnl gives proper OEM part numbers so you *could* possibly find NOS.

As for the fuel pump, let me try to explain it a little better. If you follow your lines from the fuel valve (petcock) to the fuel pump in the triangular cavity under the seat (all on the left side of the bike) you will probably notice there's a break in the line in the middle where there is a brass fitting. It's like that from the carburetor to the fuel pump as well. You may have even used those breaks when you've had to take the tank off for carb cleaning.

So far, so good? OK.

Take the line that goes from the petcock to the fuel pump and detach it at that middle join. Take the brass fitting out of the line if it ends up on the not-fuel-pump side. Now, working the other way, take the fuel line off the carb. Okay, you've disconnected the fuel pump's gas flow, now disconnect the fuel pump's electrical current (you'll see that join when you're pulling the pump out of it's spot under the seat). Put said pump on a shelf for cussing at later.

OK now here's the fun bit: take the remaining fuel line that's attached to the bike (should still be coming from tank) and work it around to join onto the carb. Join that line up to the carb. The line may be a little stiff or small, I used a touch of vaseline to lube the carb inlet. While you're there, make sure your vacuum line is still intact (it's a much smaller line and should go from the fuel tank to a port on the rear-left head).

With that, you're done. Fire 'er up and see if you have dying issues when riding. It should be all good unless you have further fuel flow issues.

FWIW, here's Jamie's link for petcock valve mod, should you also want to pursue that option:

Daugherty Motorsports - Tank Valve Petcock Modification

I hope that helped, and I hope it wasn't too simplistic and made you feel like I was patronizing. I was mentally going through the steps as I did them and was trying to remember every detail.

 

Hopefully I can take a look at the fuel pump tomorrow or Sunday. Thanks for the help.
It looks like the oil seal is available, but it doesn't look like it can be replaced without splitting the case. I don't really know how to explain why - I was hoping someone knew what I was talking about.

 

wait wait, that wouldn't be the pushrod per se, that could also be the gearshift linkage. Do you have a Factory Service (or even Clymer) manual?

If you don't (yet) I'd be glad to look up the procedure for you, provided you can tell me which part number (or which fiche and part#) you're talking about. I couldn't imagine you would have to split the case for a simple oil seal..... but then again....

 

It is the pushrod. I've been looking around on the internet and have found that you are "supposed to" split the case the correctly replace the seal, but people have done it without (temporarily). I also found a cheap fix that I'm willing to try - slipping some shrink tubing over the rod where it meets the seal.
Yes, I do have the Clymer manual, but I haven't checked it yet.

 

+1 for the cheap, easy and revertable fixes. Sometimes the cheap and dirty fixes last longer than you'd like, too. :-D

That suuuuucks about having to split the case for that, I was going by memory on what I had to do for an older Honda in my stable's pushrod seal; it was as simple as drain oil, pick out seal, put in new seal, put oil back in. But there again, it's also a simpler bike. I'm wary of splitting cases- it tends to break the magic oilproofing and will somehow find a way to leak no matter how well you bond it afterwards.