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Discussion Starter #1
I was given a 85 VN700 by my father in law a few years ago, finally able to start working on it about a year and a half ago. When he last rode it the ear shave had been done and a lot of other work, he had pulled the carbs because of fuel issues after the shave I'm guessing, carbs were rebuilt and then he never got around to getting them back on. So it's been sitting for at least 15 years. I still need to get the:
tank mounts
different alternate petcock
moly paste for the drive after I took it apart to inspect it (woohoo it was dang near perfect!)
Carb rebuild kit
tires
fuel cap (original or weld a different style on)
and a couple other things I can't think of.
It's almost there. So I got bored yesterday and decided to rig up the tank on the bike because I really wanted to see if it would even start. It's on the center stand right now with the final drive off. Battery would turn it over really easily when the spark plugs we're out, and yes Sparks from all plugs, but would quickly lose juice after a few tries. Hooked it up to my car and much better luck, after a bit of false starts it finally started and it was awesome.
Now I have a couple issues to look at based on running it a few times, very slow and erratic throttle response (thus the rebuild kit), and knocking from what sounds like the rear cyclinder towards the top, maybe, have to do it again today and narrow it down.
Researched on here last night, and it looks like it's either the ACCT or the lifters, question is can I get to the lifters without completely removing the engine if that's what it is? Really hoping it's not cyclinder slap because that would just suck. I know it ran well when my father in law was riding it, he's no mechanical idiot. Thanks for any help!

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Good luck to you! This is a great place for information. I'll help you where I can.
 

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The air bypass system has a valve just behind the top of the rear cylinder. It makes a knocking sound at idle. Some people remove that altogether when they do an ear shave. I didn't, because I like how it pops when I decel. That system might still be intact on your bike.

Try removing the vacuum hose from the right carburetor (and blocking off the nipple). That is the vacuum supply to that valve. If the knocking changes or stops altogether, than it was just that valve making noise.

For the erratic throttle response, you could have vacuum leaks too. Before replacing the carb boots (between carb and engine), check/replace all vacuum lines, and rebuild the carbs. (Ask me how I know if a bad seal in the carbs can cause a vacuum leak.... ) I was able to replace ALL the vacuum lines with a $4 piece from Farm and Fleet.

If the carb boots themselves are leaking, you can coat the outer surface with RTV Black Ultimate to at least temporarily seal them. This saves you from $70 boots, only to find they weren't the source of leaks.

Get yourself some Teflon spray and spray the inside ends of hoses/boots before putting them on. They slide in much nicer that way.

Check your slide diaphragms and your enrichment diaphragms (watch for the tiny o-ring and the large spring under the enrichment covers!!!) for cracks.

Spray your slides down with Teflon spray so they slide easily and don't build up deposits.

Good luck!
 

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A loose cam chain does not make what I would consider a knocking noise, more of a rattle, and lifters usually make a clicking noise. Hopefully it is not the rod big end bearings or the crank bearings. If you believe you may have a vacuum leak, take an unlit propane torch, open the valve a little, and with the engine running, move the torch around where you thing the leak might be. If there is a vacuum leak, engine idle will increase instantly as it sucks in the propane. I had both the enrichener diaphragms fail on my '02. They literally melted, leaving a gooey mess. I believe it was caused by ethanol gas. I use good old WD-40 on the boots and hoses. I even use it for mounting tires, though I prefer Vaseline.
 

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Discussion Starter #5
So I realized yesterday I never actually tightened to boot clamps, did that and finally got the bike to idle regularly. Still slow on throttle response but seems better. Bike does sound better as it warms up.
While my wife was on the throttle I got down with a screwdriver to narrow it down and it does seem to be comming from the top of the cyclinder, but it's hard to narrow down.
I'll take a look at the ACCT this week when I get a chance and see what that does. But leaning towards the idea the engine is coming out.
Currently no vacuum line on the right throttle, grabbing a cap today for that, and the other side. Have the correct TW200 petcock on the way, I guess I didn't pay enough attention when I ordered the first one.
I am making my own coasters, will get them on this week, but the little vents aren't making much noise.


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Discussion Starter #6
Also I did remove that valve and the two hoses last week, before I started it.

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I would not consider pulling the engine unless you have no choice. Especially if you don't really know what you are looking for. There are 2 ways to do it. Quick and dirty, and slow and methodical. I did mine the slow and methodical way. I disassembled a good part of the bike to get things out of the way. I bagged and labeled every part, and put them in large boxes. The seat, tank, and sidecovers came off, the complete intake and exhaust systems, the cooling system, battery. all the wiring connections were disconnected and labled, it took me the better part of a year to do it. I just couldn't find the time. One thing I did not do was remove the bevel drive gearcase. With everything out of the way, I built a homemade wooden dolly with casters on it, rolled it under the engine, put shims between the dolly and the engine. and using tapered door/cabinet shims, I was able to position and reposition the engine as needed. I was able to move it forward and turn it just enough to disconnect the front splines from the driveshaft. Then I just rolled it out from under the bike. That is something I hope I never have to do again. Then main reason for pulling the engine is to replace the stator. People have rebuilt these engines, but even as much as I like the bike, and as many miles as I have on 2 of them, it's just not worth it to me. Don't assume the worst until you've ruled out everything else.
 

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FREEBIRDS MC CENTRAL NY
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Pulled mine in less than six hours...

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Discussion Starter #9
Pulling the engine is the last thing I want to do ha. Sunday night while sitting there explaining to my wife what the possible issues were she suggested I just pull the engine and tear it down completely. I was not open to that. I already did the stator mod myself last year just to avoid that in the future, bonus when I ran it Sunday I checked the volts, she charges! Well at least when cold, we'll see what happens once everything heats up to running temps, wiring checked out so far, fingers crossed. Another reason I don't want to pull it is that once I do, I might as well check everything once it's out, rings, bearings, gears all the goodies. And that would take all summer since once fire season gets going I'm gone, and any chance to do some riding gets burned up too. Plus I don't think she realizes it could be a sizeable sum of cash for any parts needed, but mostly I'd like to ride it for a bit before doing that.

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Discussion Starter #10
Also since I think I reached the post minimum.... Here's my beasty!

From about two weeks ago before I started this last round of electrical, fuel, and oil work.


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Discussion Starter #11 (Edited)
So here's a video of my recent run up. Unless someone's got a great idea I haven't thought of, it looks like the engine is coming out. At least partially so I can get the top cover off. Screw driver trick narrows it down to the top of the cylinder. ACCT looks good based on grambos method of checking. Removed carbs and rear exhaust to check out the valves, intake looks good, have to grab a mirror from work tomorrow to check the exhaust. From what I can see through the spark plug holes those look good too. What do you guys think? Ill remove the ACCT completely to make sure it good, but I'm out of easy ideas.


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NewB to Vulcans
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Sounds a little like a stuck valve, have you tried a slug of seafoam in the oil?
 

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Discussion Starter #13
I have not, I have a bottle so I'll try that after I finish rebuilding the carbs. Thanks!

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Discussion Starter #14
Late update: after trying a few of the tips you guys gave me, engine is coming out. No change in ticking/knocking sound. Was able to go for a quick ride down the hill and around the school parking lot a few times to see if getting it nice and hot would loosen up a stuck lash adjuster if it was that, no change and just plain sounds like crap. No big deal though, been going through Roach's rebuild videos and doesn't look bad at all. Found some metal flakes in the oil screen so it needs to happen anyway. So my wife and I will tear it down this fall/winter and check everything and do needed upgrades. Will be a good time to do other stuff also. I'll update on progress and any issues found and total cost along the way. The bike was free but I really like it and am willing to put a good lump of cash into it to make it run great and give it another 20 years of road time.

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