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Discussion Starter #1
Just wanted to offer a word of caution to those of you out there dealing with engine knocks. In my case I acquired a 2002 750, with under 4700 miles, that had a " rapping" sound that seemed to be coming from the upper portion of the front cylinder. I got a lot of advice about acct's. valves, etc. and did a lot of checking to try and determine the cause. After finally deciding to remove the engine, I removed the front cyl. head and cyl. exposing the front piston and found that it had obviously spun the connecting rod bearing. Just wanted to let you know because the longer an engine runs like this, the more the damage will be.
 

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Linkmeister Supreme
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Thanks for the word of caution dodger. We always want to believe that a problem noise is something easily and inexpensively fixed. Your experience shows that we are not always so lucky, and a complete engine teardown is required. Good luck with the repairs. :smiley_th
 

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Calif Rider
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The previous owner must have really over torgued the engine. At 4700 miles the engine was not even broke in yet. Sorry to hear about the damage, to bad it was not something
simpler.
 

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Could have been a defective bearing. But how did you determine it was the con rod bearing without splitting the cases?
 

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Discussion Starter #5
Jerry: Once the cylinder (Lower portion) is removed, both connecting rods are visible where they connect onto the crankshaft journal. The front connecting rod was extremely loose and able to be moved up and down. The damaged bearing had been mulled up between the rod and crankshaft. After I split the case and removed the connecting rod, what was left of the bearing was paper thin.
 

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Ok. I have never had a Vulcan 750 engine apart. So did it destroy the crankshaft? I noticed a new crank is $650.
 

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Discussion Starter #7
There was some light scoring on the journal and connecting rod. A local machine shop has already got them back to specs. Just waiting for a bearing to arrive so they can set it up with the right clearance. Going to run around $ 350.00
 

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Just wanted to offer a word of caution to those of you out there dealing with engine knocks. In my case I acquired a 2002 750, with under 4700 miles, that had a " rapping" sound that seemed to be coming from the upper portion of the front cylinder.
Not sure what you meant by "acquired" ...are you saying you knowingly bought a bike that made a noise like that?

Hope you got a break on the price.
 

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Discussion Starter #9
Call me a gambler. Yes, it had the sound when I bought it. Based on the sound, mileage, and my then thoughts about Kawasaki, I didn't think it would be a rod knock. The rest of the bike is in like new condition. I'll have about $1,400 in it when finished.
 

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1986 VN750
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Call me a gambler. Yes, it had the sound when I bought it. Based on the sound, mileage, and my then thoughts about Kawasaki, I didn't think it would be a rod knock. The rest of the bike is in like new condition. I'll have about $1,400 in it when finished.
$1,400 total investment after repair? Pretty solid for the year and mileage.

My '86 with 24k miles ran me $1,100. It was fairly mechanically sound and in fairly good visual condition. I look to have to put another $200 into it, totaling it up to around $1,300.

I'd say when all is done you made out well :beerchug:
 

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Grambo Trick Works !!!

Noticed my '85 Vn700A was having a start up "clinging" sound the last couple of times ive started her up.Once warmed up the sound would stop. Had this bike for 2 years now and never heard this sound before. Did the Grambo Trick and now she purrs away like she did when i first got the bike. Its totally amazing, i think she sounds better than ever no more noises! How simple of a thing this is to do!! Im thinking about including the procedure every time i do an oil change.
I started the Grambo Trick on the front cylinder since that seemed to be where most of the noise was coming from then did the rear cylinder. Also did it with the engine off after she had been warmed up.
 

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If only it had 6th gear..
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Noticed my '85 Vn700A was having a start up "clinging" sound the last couple of times ive started her up.Once warmed up the sound would stop. Had this bike for 2 years now and never heard this sound before. Did the Grambo Trick and now she purrs away like she did when i first got the bike. Its totally amazing, i think she sounds better than ever no more noises! How simple of a thing this is to do!! Im thinking about including the procedure every time i do an oil change.
I started the Grambo Trick on the front cylinder since that seemed to be where most of the noise was coming from then did the rear cylinder. Also did it with the engine off after she had been warmed up.
i think you should do the manual conversion. Then you'll really experience quiet :smiley_th
 

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Thanks Dave your probably right, but shes really quite right now. Didnt you put a post up that showed a threaded bolt with a lock nut holding the bolt in the housing? Or, was that someone else? Duh, weak brain cells here tonight :)
 

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Linkmeister Supreme
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Thanks Dave your probably right, but shes really quite right now. Didnt you put a post up that showed a threaded bolt with a lock nut holding the bolt in the housing? Or, was that someone else? Duh, weak brain cells here tonight :)
wib did an ACCT to MCCT conversion like you describe:
http://www.vn750.com/forum/showthread.php?p=169878#post169878

Check out dirtrack650`s post #29 for a very simple conversion which requires only a hole be drilled and tapped for a set screw. :smiley_th
 

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In my experience with those ACCTs, they are junk. Both the design and materials are defective. My first ones failed at around 15,000 miles, I replaced them with new oem ones, they failed after only about 10,000 miles. The vibration simply wears out the threads between the plunger and the body. The Grambo trick will last for a couple hundred miles or so, and then the noise will come back. This is because the worn threads allow the plunger to back out. I gave up on the ACCTs at about 25,000 miles and went with the manual ones from TOC. 71,000 miles and counting, still no problems. I have not even had to adjust them. I did adjust them once, about 2 weeks after installing them, because I apparently didn't get them tight enough the first time. No problems since. Probably the best mod you can do for the Vulcan engine.
 

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..have a vulcan good day!
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Probably the best mod you can do for the Vulcan engine.
x2 !

:smiley_th
 

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Captive New Yorker....
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Hi. I'm going to have to pull my engine to replace my Stator, but I'm also noticing a knocking noise that is intermittent. What is the manual modification from TOC?? Thanks!
 

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Captive New Yorker....
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And what are ACCT's??
 

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