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Discussion Starter #1
Hey guys!

I've had 2 Vulcan 750's in the past. I was riding Ortega Highway here in So Cal a couple weekends ago and I ran into the owner of a local Kawi dealer when I stopped for a break at The Lookout Roadhouse.

We started talking about old bikes we've owned and I brought up the 750.

He said the motors were only good for about 50,000 miles then the timing chain tensioners would go bad and he mentioned another engine problem that I don't remember. He said they were the most complicated V-Twin he ever worked on and they were expensive to work on becasue of that.
He said with 50,000 miles or more they wern't worth fixing because it was so expensive and the bikes wern't worth much with that many miles on them.

I had about 20,000 miles on my 750's when I sold them.

So my question is this......How many miles do you have on your 750's AND have you had any engine problems with yours??
 

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Her personality traits

Hi:

I have a 93' VN750 with 15K. These are not problems that I have but are worth mentioning. When she warms up really well. She wants to start but doesn't. Very rare that this happens.
In the mornings after sitting all night. I hit the starter switch and nothing happens. I roll the bike forwards a few feet and try again. Sometimes it works, other times I have to roll it backwards, then try to start her. It could be just me or her traits. Most scariest thing she does is rattle on cold start ups. I mean I hear this metal on metal sound in side the engine. right below where the seat meets the tank. Sounds like the piston is bang against the inside wall of the engine. But what do I know. After she warms up the sound goes away.
I ride 100% of the times with no problems. This bike shows no signs of slowing down. In fact, maybe if she did have 50k plus on her she'd slow down and not be so quick to get up and go.
Sometimes I feel that she picks up so fast that the front wheel wants to leave the ground. Weather she has 15K or 50K on her. It's the ride she gives that makes the world of difference.
Thank you
Ray
[email protected]
 

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Discussion Starter #3 (Edited)
Hi:

I have a 93' VN750 with 15K. Most scariest thing she does is rattle on cold start ups. I mean I hear this metal on metal sound in side the engine. right below where the seat meets the tank. Sounds like the piston is bang against the inside wall of the engine. But what do I know. After she warms up the sound goes away.
That "metal to metal" sound is not normal....I'd have the motor looked at, you could be damaging the motor more by running it like that every time you start it.


30 views and only ONE response?? C'mon guys don't be shy!
Then again maybe not many people have a lot of miles on their 750's??
 

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I have a 2002 750 that I bought in the spring from the original owner. He had never done anything to the bike other than plugs, oils and tires. It had 16500miles on her at the time. I have put just under 5000 miles on it in the last 9 month. I replaced the rear tire, oil, speedometer wheel drive,and battery to start the season. Then added a Saddlemens seat and a Protec drivers backrest, replaced the rear tire, had it repainted, and added the K&N airfilters. Bike was running great!! Stopped at a new repair shop and the owner asked if I had had the input spline on the rear diff checked for wear. Showed me one he just replaced a month earlier that had the pinion splines totally eat away. He put it on a lift, unbolted the diff from the swing arm, slide the 2 apart just a tad, shinned a light in there and it about made me want to carry it to a dealer and trade it off when he told me what it would cost to repair it. Splines where all but none existenting. I called 20 plus salvage yards here in the sourthern states before a found a rear diff with a good input shaft splines. Didn't have the $1200 for the new diff and coupler, plus labor, so I went with the used one. Still cost me $450 for the used diff plus $80 for the new coupler just in parts.
Don't know if it has ever been mentioned on this form anywhere but the shaft coupler and the input shaft was not greased from the factory. The coupler and the driveshaft have a lock ring to kept then in place but the pinion and the coupler float freely for the rear tire travel and without grease they eat the spines away over time. GET IT GREASED if it has never done yet.
 

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Otherwise the bike is a great looking bike, runs great, handles great, and mine gets 49 city/hwy to 53 hwy miles to the gallon on fuel.
 

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93 vulcan 750

I've got a 91 and a 93 I ride the 91, it has 43,000 miles on it, I've had them for about three years, I got them both for free, the previous owner was sick of trying to fix them and I've had a constant carb issue. I've also got an 86 Honda shadow that is always reliable.
So the rundown of the issues I've had for the past three years,
1. battery replacement-keep it maintained
2.cooling fan switch- just old
3.fork seals- keep them lubed
4.rust in the gas tank clogging the carbs
5.carb problems- sticking float(see #4)
6.Intake leaks from taking the carbs off multiple times(see#4)
I'm an auto mechanic so I do my own work, I've about about had it with this bike and the CV carbs. I'm thinking about building a custom intake and installing one carb.
It's all been pretty minor really, the carbs have been a pain because they were not tuned when I got it, they just don't like to stay in tune so I may just need to buy NEW carbs. Seems likethe Kein are like the Quadrajet of the motorcycle world, once they need rebuilt they are done. I've bought four rebuilt and none of them have been any good.
BTW I replaced the tensioner as soon as I got it, it was already on it's way out, luckinly the 93 had 15,000 miles on it when it threw a rod so I used the tensioner and cams from it
I also have the starting problem qxinfinity is talking about when you push the start button and get nothing, roll it in gear then push it again and starts
 

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Discussion Starter #7
That No grease on the spline is a COMMON problem with the Vulcans from what I hear. Kawasaki should have done a RECALL on the bikes because so many wern't greased at the factory.
 

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I have a 1989 VN750 (my 1st bike). For the first 3-4 months the bike was a dream, now i'm finding oil leaks out of every which crack, the battery never seems to hold a charge (even when brand new), and i hear this "bubbling" noise after running it a while, i thought it was lack of antifreeze but its not the case. Recently i cant get it to turn on, when it does, the RPMs drop, and i have to open the throttle just to keep it on, as soon as i open the choke, it turns off, then doesnt start again...

I hope its just the battery, it seems whenever it has a strong charge it turns on and runs fine, since i'm a total newbie with motorcycles, all i can do is try this, and maybe tow it to a shop if it doesnt work out.

...Other than that the bike's GREAT! I love riding it as it is (or is supposed to be) my daily commuter.
 

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50cc engine is about the least engine horsepower/torque I would ever consider. Anything smaller than that is not only dangerous in an emergency (to get “out of the way”), but is not highway worthy when traveling interstates or busy highways. THIS IS IMPORTANT! Many people underestimate this need.
 

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i just bought a 2004 vn750 with 33000 miles on her and he gave me the maintainence records for everything ever done to it.. had the shaft replaced and stator replaced and normal wear stuff tires and batteries,, but this thing starts up even in the cold and runs awesome i wouldnt be afraid to ride this thing to sturgis and back! but if she blows there are tons of low mileage engines to buy and swap thats the upside of owning a bike thats been in production for almost 20 years!
 

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Discussion Starter #12
Time to resurrect this thread......

How many miles on your VN750 and what problems in any have you had??
 

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The Vulcan 750 does have a lot of problems, but if you know about them to begin with, they can be avoided. I have owned two Vulcan 750s, both bought brand new. The first was a '93, and I put 80,000+ miles on it before selling it to buy another kind of bike. That bike didn't work out, and I kept it less than a year. I looked at all the other 750 size cruisers out there, and couldn't find anything I liked better than the Vulcan. So I bought another new one, an '02 model, which I still have. It currently has 92,000 miles on it.

Right now, the engine is out while I wait for parts. The stator failed, and the engine has to come out to replace it. While I have the engine out, I'm also going to replace the balancer dampers. These have a tendency to fail over time, and when they do, they allow the damper to wobble around, and grind right through the case. The stator and balancer dampers are two of the Vulcan 750s problems.

As mentioned, the biggest problem with the Vulcan 750 engine is probably the cam chain tensioners. They are defective from the factory, both from bad design and poor quality materials. I went through 3 sets of them on my '93. They have a steel plunger inside of a soft aluminum body, and have a spring which lets them advance as the cam chain wears. But the spring is not supposed to hold them in place once the plunger advances. There are large coarse threads on the outside of the steel plunger, and matching threads on the inside of the aluminum housing. These are what actually hold the plunger in place, so it cannot back out. It works when new. But as the tensioners wear, and mostly what wears are the threads inside the aluminum housing, the tensioners will no longer stay in place. The threads wear because the pressure on the plunger, which pushes against the cam chain guide, is not constant. The cam chains whip around a bit while the engine is running, hammering on the plunger, which in turn hammers on the threads in the aluminum housing, which wear fairly quickly, and the more they wear, the faster they wear. I cut a worn out tensioner body in half, and the threads had almost completely worn down to nothing.

When the tensioners become worn, they don't tension the cam chains properly, and the chains get noisy. If you notice this when it first starts to happen, and replace the tensioners quickly, you can avoid cam chain damage. Way back, your only choice was to replace the tensioners with new oem parts. That can get expensive. On my '02, they started to fail at around 25,000 miles. I replaced them with more oem parts, and they started to fail at just over 10,000 miles. It seems the newer the tensioner the faster they wear out. This may be caused by them being made with worn tooling. The Vulcan 750 had a 22 year production run, and the later models likely has sloppier tolerances than the older ones. But now there is another solution to this problem. A company called TOC (http://www.tocmanufacturing.com/Products.htm) makes MANUAL tensioners for the Vulcan 750. I got some of these at around 35,000 miles, and they are still working just fine. I have adjusted them once between 35,000 miles and 92,000 miles. Some people have rigged a manual tensioner out of a oem tensioner by using a hardware store bolt and lock nut to replace the plunger and spring. Do this at your own risk. I certainly wouldn't trust it. Especially since the TOC tensioners cost less than the oem ones, and last forever.

Next up is the final drive splines. I also consider this a design flaw, but if properly maintained, they will last forever. While the splines that mesh with the rear wheel require lubrication on all shaft drive bikes, The Vulcan 750 also needs the splines on both ends of the drive shaft itself, which is inside the swing arm, to be lubed about every 10,000 miles. Obviously that requires some dissassembly. I recommend using a moly paste. Either Honda Moly 60, or what I use, Guard Dog 570, which is 73% moly.

There is another issue with the final drive splines. Most were not lubed at the factory. On my '93 I waited until the mileage recommended in the manual to do this job, and found the splines completely dry, with some damage. I cleaned up the damage as best I could, and soaked them in moly paste every 10,000 miles. They never failed. On the '02, I did this less than a week after buying the bike new. I found the same thing. Splines completely dry. Only this time I got to it before any damage was done.

The Vulcan 750 also has starting issues, which I believe is caused by a weak starter and ignition system. The starter seems to turn slow no matter how strong the battery, and at that slow cranking speed, I don't believe there is a good spark from the ignition system. The problem seems to be worse when the engine is hot. I don't know of anyone who has found a sure fire answer for this.

That's about it for major problems. I've had carb problems, petcock problems (which I believe to be caused by ethanol gas) the flimsy toolbox door breaks off right away, and the chrome plastic swing arm caps tend to fall off unless glued on. Also, completely removing the CA evap system and the air injection system will make the bike run better, and solve some ridability problems. The evap system can prevent the gas tank from venting properly, and the air injection system causes the exhaust to run hot, and lean backfiring. Turning the pilot air screws out 2 1/2 turns also helps, especially at idle.

The Vulcan 750 IS a very complicated engine, with twice the parts of many v-twin engines. Four overhead cams, eight valves, four cam chains with a jackshaft, a counterbalancer, hydraulic valves, liquid cooling, four plugs, shaft drive, very complex carburetors, it has more in common with a Ferrari engine than a Harley.

Nevertheless I love it, and wonder what I am going to replace my '02 with when it finally does wear out. Other than it's mechanical issues, it's the perfect bike for me. Tubeless tires, a centerstand, shaft drive, lots of power for a 750 v-twin, and it is hands down the most comfortable bike I've ever ridden. I expect mine to make it well past 100,000 miles. But I bought it new, knowing about it's problems, and took care of it. I probably would not buy a used one.
 
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