Where to start with 86' VFR700F that hasnt been touched in over 5 years?

The rear clamps (if they're like mine) seem like they can take forever to be fully tightened up, due to the pitch of the threads. That also lets you get them very nice and tight. Mine are stainless t-bolt band clamps. The ones at the header to collector joint are stock clamps. I think I like the t-bolt style better.

A though: Have you tapped the cores out of the trapps and made sure that there is still fiberglass packing in there? Just remove the clamp, undo the bolt at the foot peg, and then use a long dowel and a hammer to gently tap the endcap and core out. It's surprisingly easy.

 

I have not tried that. What would that do? If you scroll up in this thread, you can see a picture of a hole in the muffler. That brown fur stuff is fiberglass im pretty sure.

 

The hole certainly isn't going to help, but the purpose of the packing material is to absorb the high frequencies of the exhaust note. The packing heats up and "burns out" front to back. And as it does so, the exhaust note gets raspier and crackly/popping in sound.

My "other" bike had a few exhaust leaks at the collector joints, and it made an awful racket when reved up. Nothing like the deep sound my bike makes.

So I'd at least double check that there's no leaks all the packing is in place. And the hole could be patched with some aluminum sheet and a pair of pope clamps. Not pretty, but functional.

 

Your bike, I imagine, sounds exactly as it did 20 years ago with a fresh set of pipes. It sounds great.

I've been in the middle of a waiting game working on the brakes and upgrading the chain and rebuilding the forks. Its been really slow though as I was waiting on parts and was borrowing someones aircompressor to clean out the brakes. He took the compressor back a few weeks ago so I was at a standstill. Went ahead and just bought one of these babies. I hate borrowing from people.

SENCO Air-Powered Nailers, Staplers, and Fasteners

I tried craftsman and harbor freight compressors and they were literally pieces of shit right out of the box. The compressor I was using was a 1 gallon senco and it worked perfectly, so I just went ahead and bought the next one up. I havent been on the bike in at least a month. So sad

 

Well, given that mine sat for over 10 years barely being ridden, until I got it, it hasn't seen a lot of mileage over the years. Half the mileage I've put on it in the last 5 years, and most of that within the last year. But it's already losing about 1" or so of the packing (on the one side that I checked), so with more mileage (and especially with the hole in the side of the can), yours might be down more packing.

added:

And yeah, not being able to ride sucks. I'm currently waiting on my glasses to come back, and while I can drive without corrective lenses (legally), I don't like riding without the extra definition.

 

So I put on new SS brake lines and new organic pads... Either I'm just still terrible at bleeding or organic pads are just shitty. The old pads werent really bad but I ordered new ones before inspection and just put em on. The bike actually feels like it brakes worse than before but I read that new brakes need to bleed in. Is it possible my rotors might need resurfacing and that I have old brake glaze on them?

I notice with the engine (this has always happened I just never posted about it), that right when I roll on, the bike aburptly accelerates and when I get off throttle, it abruptly decelerates. Another weird thing it does is if I rev it and let off, as the revs go down, it will fall below idle then come back up to idle.

 

What kind of poor braking are you seeing? poor feel from the lever? or no matter how hard you apply pressure, the pads don't seem to bite into the rotor? With the SS lines, you should feel the lever come back a little ways, and then *stop*. No movement (or very little) after that this is the system pressurizing and pushing the pistons against the pads, and then once it's moved the pistons, there won't be any more movement to be had. From this point, the rubber lines would expand, given a "soft" or "spongy" feel. If the brake lever feels at all soft, then you probably still have air in the lines. And getting all the air out is a major PITA. I found that there was a bunch of air in the banjo bolts at the master, since that's the high point in the system. Getting the air out of there was an adventure.

I ended up pulling in the brake lever, and then cracking open the banjo bolt and closing it (like the brake bleeders down at the caliper), and releasing the brake lever. About 50 times. Messy, but it got the job done.


I've always thought that the bike had a pretty sensitive throttle, it's just something that I've learned to control. As to the dropping below idle and then stabilizing, that may or may not be ok. How much does it go down? and what do you have the idle set at? (it might just be running rich for a moment as it settles out).

 

The front brake would just never really stop the bike once its fully pulled in, and additionally, I have the brake lever adjusted so that its all the way forward so I can continue to pull it in as much as possible. I'll try bleeding again. I did it probably about 20 times... When do close the banjo? Once the lever starts to pull in more?

 

It's like bleeding at the caliper:

1) pull in brake lever (it should stop before it gets to the grip, but maybe no if there's tons of air in the system)
2) crack open the bleeder (or the banjo bolt)
3) wait for it to stop hissing out air/fluid
4) close bleeder/banjo
5) release the brake lever slowly, over the course of a few seconds

repeat until no more air comes out

Did you start with fluid in the lines, or from empty lines? (it's a long process if you start with empty lines)

 

Empty... I'll give it another shot.

 

After having not ridden the bike for about a month, it has developed this issue when accelerating, at around the 3.8k and again around 4.5k, the bike sounds like it has been starved of fuel or air or something for a split second. I think think its misfiring, but its kind of like a quick chug, where you actually dont hear the engine for a split second. It only happens at roughly those 2 rpm ranges and only during a steady roll-on. If I rev it quickly, it wont happen.

 

anyone got any thoughts on this? also I just bought a new fuel filter, but obviously it'd be too late for that if theres junk in the carbs. The engine has that issue all the time even when warmed up and its always in the same spots.

 

Sparks, I've enjoyed following your progress on this thread. Kudos to you for being willing to learn the hard way (i.e. mistakes) and wanting to get your hands dirty. Having refurbished several second gens, I think this bike has tolerated your "learning curve" very well, as Honda's are prone to do.

However, any thorough refurb should be approached systematically as opposed to the scattered approach taken here; compression, valves, plugs, timing check, carb clean, etc. For example, the so-called "dust seal" issue with the brake caliper is a serious safety concern -- long-inactive brakes need to be completely and systematically inspected, bench-cleaned, rebuilt and correctly installed. Diagnosis is much more difficult when jumping about.

Having said that, I think you've overstepped your abilities regarding the carbs -- I suspect all your continuing drivability issues are carb-related. I would suggest a professional rebuild, about $300 (I know; easy for someone else to say...).

And, these bikes don't have noisy valves, sensitive throttles, gas leaking out exhaust ports, spongy brake levers, flat spots, variable idle, etc, etc. Nor do they require re-jetting (outside of racing use). They're Hondas; that stuff's not "normal."

My 2 cents, and zipping up the flame suit.

JOE

 

All the issues I've mentioned in the thread have been fixed except this one.

 

Unless you know your carbs have been thouroughly cleaned out of potential gunk by hand and compressed air and wire you won't know what the problem is.
Also look at fuel cap vent, fuel pump, fuel cut-off relay.

 

And I had a similar issue when I vented the float bowls to the airbox, instead of to outside air. The vacuum level in the airbox was enough to upset the fuel flow into the carbs (pressure in the fuel bowl vs. pressure in the needle tube, or whatever it's called).

 

I started the bike today and it just idle'd violenty so I checked the plugs and took the carb apart. Everyhthing looked good to my eyes as far as the carbs go. Maybe theres a bunch of crap in the circuits and the main body itself.

Woody can you explain that process exactly? I dont know what you mean by "vented the float bowls." How does one do that?

These plugs have around 150 miles on them.

 

There are air vents for the fuel bowls in the carb. It sets the pressure in the fuel bowl to the same as outside the bike (so that the air rushing past the slide creates a vacuum that can pull fuel through the fuel tube/jets). I ran the vents to what I thought was the right place (the filtered side of the airbox), but the airbox would be under enough of a vacuum that it fuel starved at about 6K rpm. Then I remembered how things were routed on the carbs for my wife's Hawk, and just left the vent open to the atmosphere (which could allow dirt into the carbs), and it's been much happier ever since.

 

Your plugs look OK, but plugs can only be accurately read (for jetting purposes) after a hi-rpm run and shut-down... or after a few thousand road miles for general cylinder health. Yours look wet and dark, just what you'd expect with incomplete combustion -- like your violent idle.

The four air vent lines gather together at the rear of the carb set, very near the fuel inlet line. The vent can be left to terminate there or the line continued downward with the others near the footpeg. Follow the vent lines to each carb and visually inspect them for leaks/cracks. They have o-rings at the carb ends, which can leak if mis-handled, though I've never had an issue with these o-rings.

If your erratic idle appeared this one time upon start-up, I'd focus on the carbs as the culprit. It could also be caused by very bad gas, meaning old stuff with water introduced into it during storage from warm/cold cycles.

Keep at it, you'll win.

 

how new are your carb boots? old ones need replacing especially if you have ripped the carbs off a dozen times..... and when you get new ones make sure you install them correctly( yeah there is aright way and a wrong way)