Valve Adjustment And A Coolant Leak And ...

First post and I'm afraid I'm asking for something. A little help.

I'm the proud owner of a 1984 VF750F with about 45,000 to 48,000 kilometers on it (about because the odometer stopped working at 41,300 kms last summer and I've been riding).

I was thinking it was good timing to do a valve adjustment on the bike. I've read a lot of posts here and other forms. I looks doable if you take you time and have some semblance of mechanical skills. I'm somewhat skillful and I don't mind picking up the tools that I needed over and above what I have.

Sooooo ... I start by taking a look at things, noticed a coolant leak from one of the water pipes ... nice, now I know why I had to top up the coolant rather frequently. I order up all the bits I think I should need for the endeavour. They get here and I start doing my thing. I've taken my time with this as I have no need to rush it. At first I was thinking I could just reach under and pull out the water pipe after loosening the hose clamps. After ogling things for a bit I figured there wasn't enough room to do so. The carbs are going to have to come out.

I wrestled them out ... I gotta tell you guys, holy f^c% are you kidding me???? Here is where the questions start.

First with the carbs, should the "assembly" of all four carbs have some stability to it? Once I got them loose they are sorta hang'n together like there's some taught elastic allowing them to float around some. It certainly wasn't what I expected. Is that normal for them?

Second, the valves were noisy. Not overly so, just with what I figure being 48,000 kilometers on the bike I should check them. I have two "service manual sources" one that says .005 the other says .006. I know that's pretty close but, almost all of the valves were way tighter than this. Less than .003 and only one that was .004. I thought I was measuring them wrong so I dug out the service manual and followed it through and double checked it all. They're all tight,

I was expecting things to be "loose", meaning to me that I would easily slide .005 feeler gauge under them.

Am I wrong in my thinking? I don't have anyone around to compare engine noise with. I haven't found any older VF guys in my neighbourhood just yet. All my riding buddies are more into newer bikes and when things get beyond an oil change they're challenged.

Some thoughts. Some help. A few jokes. Anything to set me in the right direction would be appreciated.

Cheers, Guy

aka, canuk_guy

First of all, welcome!

There should be some 1st gen owners along in no time with advice. We do love photos here, and as you're likely to hear from others, without a photo of your bike, it doesn't exist! :biggrin:

With your buddies riding new(er) machines, it's great that you're keeping a vintage machine going. I'll bet none of them sound anything like that V4 growl!

Carbs - It sounds like you removed the baseplate all the carbs were bolted to before removing the carburetors themselves. Not a good idea. Leave them as a unit. It does make them harder to remove and reinstall when cold. If the machine runs, always do it hot. Not always possible and in this case (cooling system issues) recommended. Remove hot, leave to cool. Try using a hair dryer on the carb boots when reinstalling.

The carbs are only held together by pipes and linkages otherwise. Speaking of pipes, removing/installing without the plate in place can (in my experience, will) damage the plastic fuel/vent tubes and desync the throttle plates.

Valves - The early v-fours are always noisy. Some lose clearance, some gain. Generally, losing clearance is valve seat/valve head wear and gaining is wear between the rocker arm adjuster and the top of the valve or cam lobe/rocker arm pad wear. It's unlikely the heads and valves would be worn out at this mileage and the camshaft/rocker arm wear issue is well documented online.

Leave the carbs attached to Plenum while removing. If you try to remove them separately the fuel tubes will crack. How do I know that? Been there done that. Good Luck on your work

Just to let you guys all know ... I'm not just a one hit wonder. I've been having trouble finding time to work on the VF750F. This is how my valve adjustment is coming along. :goofy: What can I say. I did put the plenum back on the carbs, thanks for that tidbit. I had to chase down a couple springs that tried to run for freedom. Other than that it's a waiting game ... waiting for parts, seals for the carbs.

[image: 20160311_164434_001-M.jpg]

Cheers, canuk_guy

You should probably order a stator gasket also. You'll need to remove the cover to turn your engine over to get to TDC on the compression stroke for each cylinder. You'll need two feeler gauges, an offset 10mm wrench, a flat head screwdriver and a 17mm wrench or socket to turn the engine over. If you use the short gauges then you probably should attach something to them in case they come loose and fall down inside the engine. I bought some from McMaster that are about 10" long. The valve adjustment tends to get tighter as the engine runs. Usually the noise is the cam chain adjusters getting old. If the sound goes quiet during acceleration and comes back during the decel, this might be the problem. You shouldn't be able to get much slack between the chain and the cover between the gears, it should be pretty tight most of the time with just a little slack at times.

You can still get the coolant tube O-rings from honda. The are flat and not your typical O-ring. The round ones can be a little tricky to get seated correctly.

You may already know this but its worth saying, do not mix the carb parts together with the other carbs. The front and rears have different jets, needles, springs and emulsion tubes in them.

And one more thing, if you soak your carb boots in a 50/50 mix of wintergreen oil and alcohol they'll be as soft and flexable as new ones when you put your carbs back in. ...and your bike will smell good for a while.

WELCOME and more pics please .

Thanks for the info on the tools required. That's pretty well just what I used. Took my time about it and have them set at a "snug" .005. It's a good thing to have small hands at times. With two feeler gauges, a wrench and a screw driver you really don't have a lot of room for fingers. Once she's running again I'll keep that info in mind about the cam chain.

I was surprised at the condition of the gaskets as I took everything apart. The rubber gaskets were a lot more pliable than I thought they would be. I think someone else was in there not to long ago and must have replaced all the rubber valve cover gaskets at that time. I reused them and I'll keep the ones I purchased for next time. Same with the stator cover gasket. I fully expected to have to replace that one, being paper. But nope, the cover came off clean and the gasket in one piece with the cover. Nice!

I got as far as finishing the valve adjustment today. I'm still waiting on the carb bits to come in. I'll see if I can find that wintergreen oil around here. I'm guessing a great deal of cursing will ensue with the carb installation, anything to make it easier is appreciate.

I'll get to the coolant leak when I have time, hopefully later this week.

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This is how the carbs are coming along. :blush2: One I can take credit for, I think. The other looks like it's been eff'd for a while. I sure hope I can source these things from Honda or wherever. The parts guys are closed today, Good Friday so I'll just do the soak and overhaul in the mean time and troll the innernet :computer-noworky: looking to see what they're going for on eBay.

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Cheers, canuk_guy

http://www.v4market.com/Fuel-Vent-Tubes_p_256.html

Ordered a set for my 86 VFR. They are good quality and worked perfectly.

Dang!!! Those look great and a good idea too. Gets rid of worrying about those plastic tubes. I'm trolling through the site checking out other things as well. Double dang!!! This could be an expensive place to hang out!!! :unsure:

Captain 80s

http://www.v4market.com/Fuel-Vent-Tubes_p_256.html

Ordered a set for my 86 VFR. They are good quality and worked perfectly.

Stretch: "u should probably order a stator gasket also. You'll need to remove the cover to turn your engine over to get to TDC on the compression stroke". :huh:

Why waste the time ?? It's easy to remove the crank-end access cover window to turn the crank or, with the plugs removed, just bump over the rear wheel to turn the crank. The EXACT alignment marks are vital to cam timing, but mostly UNimportant when setting valves, as they can be measured and set ANYWHERE the lobe is generally pointing away from the valve tops. :comp13:

As for the alloy tubes, about half the money is wasted becuz the alloy vent tubes supplied are just about NEVER needed as the OEM tubes don't crack or deteriorate like the fuel tubes do. :491:

ALSO, canukguy, judging by the ruddy dust in your float bowl, you need to drain, flush, and remove rust from your petrol tank b4 remounting carbs. :wacko:

Oh the tank will get a good flush before it all gets back together, that's for darn sure. I think I'll just order the whole set all the same. That way I won't have to worry about it.

squirrelman

Stretch: "u should probably order a stator gasket also. You'll need to remove the cover to turn your engine over to get to TDC on the compression stroke". :huh:

Why waste the time ?? It's easy to remove the crank-end access cover window to turn the crank or, with the plugs removed, just bump over the rear wheel to turn the crank. The EXACT alignment marks are vital to cam timing, but mostly UNimportant when setting valves, as they can be measured and set ANYWHERE the lobe is generally pointing away from the valve tops. :comp13:

As for the alloy tubes, about half the money is wasted becuz the alloy vent tubes supplied are just about NEVER needed as the OEM tubes don't crack or deteriorate like the fuel tubes do. :491:

ALSO, canukguy, judging by the ruddy dust in your float bowl, you need to drain, flush, and remove rust from your petrol tank b4 remounting carbs. :wacko:

I ordered them in ... first ones were definitely the wrong ones. Parts guy was embarrassed at that mistake and promptly ordered the right ones in. They showed up ... looking just like regular o-rings. He also made the comment that they should be flat like the ones that came out. These ones however, aren't, they look just like the run of the mill o-rings.

I'm going to go with them anyway as I'm tired of waiting for parts and want this together and running. If she starts to leak coolant again, I'll deal with it.

I picked up some of that wintergreen oil. That shit's expensive and comes in small bottles. I hope it works.

Stretch

You can still get the coolant tube O-rings from honda. The are flat and not your typical O-ring. The round ones can be a little tricky to get seated correctly.

And one more thing, if you soak your carb boots in a 50/50 mix of wintergreen oil and alcohol they'll be as soft and flexable as new ones when you put your carbs back in. ...and your bike will smell good for a while.

I found these same tubes on eBay and ordered them from there. That particular website can't seem to deliver to Canada. Thanks for the find, it sure helped out.

Captain 80s

http://www.v4market.com/Fuel-Vent-Tubes_p_256.html

Ordered a set for my 86 VFR. They are good quality and worked perfectly.

And now it's time to work on the carbs and then to the bike. Yea me!!! :fing02: :cheerleader:

Hey Stretch,

I gotta tell you that soaking the boots in that wintergreen oil and alcohol was the cat's a$$. The carbs slid right into place with just a little futzing around. I thought for sure I'd done something wrong as they popped right into place.

Stretch

And one more thing, if you soak your carb boots in a 50/50 mix of wintergreen oil and alcohol they'll be as soft and flexable as new ones when you put your carbs back in. ...and your bike will smell good for a while.

[image: 20160418_201419-L.jpg]

I have a few more things to do ... like clean out the gas tank ... before I start it back up. Replaced the fuel filter, some fuel lines and a couple of coolant and fuel clamps here and there that were starting to look iffy.

Thing looks dirty as hell. I'm going to have to give a good wash when I've got it mobile. The storage garage doesn't have access to a good pressure wash. One thing at a time.

Cheers, canuk_guy

Hey all,

I managed to get everything together and even get out for a few shakedown runs.

Notes: After a hard (quick). high rpm run up through the gears and you settle down to a cruise she starts to surge like she's fuel starved.  I have to say that running up there she's performing great!!  Once there and cruising she starts to shudder some.  After a bit ... feels like an eternity, but probably 30 seconds or so she's running smoothly again.  When I'm accelerating normally there's no problem and I can get up higher speeds without any issues.  I've tried this several times, each time same result.

I was thinking float height, but they're pretty well the same as they were before.  I only had to adjust one really.  And there was no issue like this before.  Although I'm not hauling a$$ like that hardly ever, it's not my riding style, if I had to accelerate hard to get back into traffic I don't want her to be surging and I'm sure on a longer run I'd be running out of fuel.

Collective thoughts?

I have to say that after the valve adjustment, it seems noisier.  I don't have much to base this on as I'm trying to remember it from last summer to this year.  I don't have anyone else to compare it to.  I've had it out for a couple of good runs, one long day ride and it seems to perform great!  Not running hot, accelerates nicely through the rpm range a little crisper than last year.  The fuel economy seems off a bit though, might be because it's running properly this year over last ... other than the surging after a hard high rpm run up through the gears.

I like riding this bike.

Thoughts on the surging would be great.  I'll do some web surfing on it to see what else I can find.  I also have to replace a leaking fork seal (again).  I replace both of them last summer before the riding season and the left one is leaking again.  Thought I'd try the OEM ones this time.

On that note ... what weight of fork oil should I try this time?  I was running 10wt Lucas Fork Oil.  Seemed to be fine, as I mentioned before, I'm not an aggressive rider any more.  I just like to sport tour my way around.

That's a long bit.  I'll let you catch up for now.  Time to get off to work to support this habit ... motorcycle tinkering.

Cheers, canuk_guy

As far as surging, try running a bit of Sea Foam through the system. I, too, rebuilt my fuel system last year. Once I got it started I couldn't get the idle down. I mixed in some Sea Foam and ran it up to temp then shut it off several times over a weekend. By Sunday night, it was running perfectly...just needed a final rinse  :)  

As for fork oil I decided to go with a heavier than stock oil (15wt) and will likely go back to at least 12wt if I can find it, if not I'll go to 10wt.  Just too stiff for daily riding for my taste. 

BTW 87 VFR700F2