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Discussion Starter #1
I'm reaching out because I have hit a road block with two major issues on my motorcycle. I have a 1998 Yamaha Vstar 650 bobber style. Rear and pipes are cut. Side license plate/brake, also a jet kit.
My two issues are as follows:
1. While installing a new side license plate bracket, I think I might of damaged the wiring. Now when I try to brake, the light doesn't come on. I was wondering if you know of a site that has diagrams or a how to video so I can go in there a see how to fix it. I know nothing about electrical. I would also need to know where to buy parts etc.
2. This second issue has to do with the engine. Recently, I have been losing power either while riding at highway speeds or on the street. For example, I will be going down the street at around 45MPH when all of a sudden I feel the bike die down. It feels like I'm losing horse power. It also sounds a lot different, like a 250cc.
So far, I have had the jets check out. Mechanic said they are within spec. I changed out the spark plugs and I bought new coils.
 

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Hello Andre, The regular shop manual has the schematics for the electrical on your bike. And it is color coded so you can see what color wire does what and where it's located for example.

I assume you moved the tag /brake/ running light to the side tag mount.

You must understand that the stock rear light uses an isolated ground.
The light bulb housing does not touch frame ground.

If your assembly is shorted to the frame there's your problem.
To fix it you might need to isolate the light so it does not touch metal
when mounted. (possible) I do not know what you have done or what it looks like so it's just an example of what to do.

Next, A loss of power can be from multiple items or a single item
that has malfunctioned or is in need of replacement.
The very first thing I would do is make sure the gas tank is clean inside. And change the fuel filter. This means pull the tank off the bike and drain the gas into a container to check for sediment.
This can also be done by disconnecting the fuel line to the rear carb.
If the tank is clean (no rust or sludge ) and you replace the fuel filter with a fresh one. try riding it again. See what changes.
If it still does this most likely you have an electrical or Carb, issue .

You must be ready to wrench on a bike thats 18 years old.
Or be ready to pay a shop or repair man. If need be.

These issues could be why the Owner sold it.
 

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Also how many miles does this bike have on it.?
 

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1. "damaged the wiring" sounds kind of vague. did you purposely move or cut any wires at all during this install? if you need to replace part of the wiring, then first you need to locate where this damage is. as for fixing it, any auto parts store or Home Depot or Lowes or such has just about anything you might need to fix electrical wiring. if you are replacing any of the wiring, make sure you are doing so with the same gauge. bring a portion of it to the store so you can match it with the correct thickness/size you need.

2) don't know much about carbureted bikes, but i would say the next thing to look at is the carb. it may need to be synced, or the float bowl/needle adjusted. if you are looking for videos on anything, just search youtube.
 

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Discussion Starter #5
Thanks for the replies guys. Let me give you more info on the bike and the issues. Restorider00 the bike has ~60k miles.
1) The bike came with an aluminum side license plate/brake light mount, but it was rusting/breaking off. I bought a steel (I think) black powder coated bracket. In order to install it, I had to cut the wires and pull on them a little to get some extra slack to mount on the new bracket. The brake lights worked before the cut, so I’m thinking I either messed up the splicing or I pulled on it to hard and something got unplugged. The cables just seemed to be original, so I would rather just get new ones. I’m using the following manual, www.technohillbilly.net/vstar.650.manuals/vstar_650_main_man.pdf and I’ll visit my local Lowes to get some wire. Thanks for that tip.
2) Some more info on the engine. While riding it the other day, the problem came up again. Riding down the street and all of a sudden I get loss of power. Also, the sound of the bike changed. I placed my hand a few inches away from the ends of the pipes. I noticed my rear head is firing but not my front one. Exhaust on rear head was hot, front head wasn’t. Not sure what to check first.
I’m at work all day today, but I’ll getting working on it tomorrow. Any info would be greatly appreciated.
 

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This sounds to me like the front carb needs attention. Or your having some issues with the coil or wiring to that front cyl.

If it only does it sometimes and not all the time I would point a big finger towards the carb and or related parts, Filter, fuel pump, gas tank
petcock, etc.

When I first got my 650 the tank was so bad it would run for a while
pretty decent and then go into a fit of sputter and back fire cutting out
and so on. The entire fuel system was serviced, cleaned carbs, new intake boots, Caswell coated the gas tank , new fuel lines and filter.

Runs like new now.

Use a Multimeter to check continuity on your rear light wires.
Most have a (beep) function to check for this.
 

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my stupidity may help

this may sound stupid, but did you get the correct plugs when you changed them? I had an fzr600 that was doing the same type of thing. I went through all the same checking fuel filter, cleaning carbs, checking coil ect ect. even replaced the plugs with same number plug that I took out. after like two weeks and a lot of needless work did I find out that the plugs were supposed to be a cr8 and not a cr7. bike ran fine after I put the correct plugs in.
 

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Discussion Starter #8
Moby, not a stupid question at all. I did double check the plugs, and they are correct. I have been looking on youtube and I found a video of a guy that is having the same problem as me. If you care to take a look, here you go.
--- Front head does't fire and only getting exhaust out of one pipe.
 

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Yeah well thats great but your condition may be totally different than
the guy on you tubes video.

Many different factors can have the same outcome.

Do not look at this video as being the cause of your problem.

If your having these type issues you need to be a Spy and start looking
for whats wrong.

Looking at videos will not cure or fix the problem.

1st : rule out ANY fuel related issues from gas tank to carbs.
2nd : Determine when the problem starts. As in cold start, after it starts to warm or fully warmed up.
3rd : Read the plugs : Sooty and black or grey ash colored, tan, ect.
 

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IMO....you're best bet is to get the bike into a shop and have somebody fix it right.

By admission some of the skills needed to do a proper job are lacking on your end.

With an electrical problem, you need to have a DVOM and know how to use it.

With the running issue, it could be electrical or carbs..... to fix either you need a some basic knowledge of how these thingss operate and how to fix them when they don't work right. So if you want, break out the books and start studying....there is a LOT to learn. Trying to fix an issue like this on a forum is extremely difficult...because there are literally a hundred things that could be an issue. since we can't see it or hear it, all we can do is make semi-educated guesses.

Or......as I mentioned, take it to somebody that can get you back on the road in a couple hours with a safe running bike. With any luck, they will help educate you on what was going on.
 

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Mick, If he even has the funds to go to the repair shop (which would be the best alternative) For novice motorcycle owners w/ limited skills.

I fully agree that a tutorial session with a repair manual might light the way to understanding whats going on here.

With 60 K miles it could be a circus act trying to find whats causing the problem or problems related to these issues .

If the OP wants to learn we are here to help. Just be ready to do some work on the subject at hand first.
 

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If you're gonna try to fix it yourself check this site.

650CCND.com Lots of 650 info, not as thorough as the 1100 KB but lots of info.
 

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Discussion Starter #13
Thanks for all the tips guys. I was able to solve the electrical issue.
Turns out the plate wasn't grounding properly since I swapped out the broken aluminum one with a steel powder coated bracket.
As for the forward head, I removed the tank, it was clean. Also, no debris on the petcock filter. Primered and painted the tank while I had it off. Checked the fuel filter as well, clean. I'm just going to take your guys advice now and send it to a shop. Don't feel there is much more I can do with my knowledge.
Going to put another coat on the bike. I'll post some pictures after she get put togeather.
 

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Discussion Starter #14
If anyone is in South Miami, feel free to hit me up. I'm always willing to get my hands dirty. I would love to learn more about how the carbs/fuel/air all come together and make teh bike work.
 

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That is the best alternative for you. A mechanic can pinpoint whats going on. If they are good :rolleyes:

If you have ruled out any fuel related issues as far as feed to the carbs go, thats fine. It does not rule out issues with the carbs themselves.
These are better left to someone with the savy to work on them.

It could be clogged jets or an Electrical issue.

I just hope for you it's not too expensive a fix. :eek:


jake :rolleyes:
 

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Loss of power could also be the result of cracked carburetor joints, the rubber 45 elbows that run into the heads. Mine was cracked for the front head and I figured if it was cracked and trying to suck more air in when I was trying to rev up to get onto the highway, that was a probable cause. Turns out both were cracked. Haven't tried it yet since it's winter but for $45 a piece it better fix it.
 

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These joints you refer to are the manifolds. They can have external cracks that do not run all the way through to the inside. As was the case with mine. From the outside they were badly cracked but from
inside smooth as glass. To be safe I replaced both of them as well as the nipple plugs for the sync connections.


jake :):)
 

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Discussion Starter #18
Update on the bike.
Took it to a mechanic, don't know how good he is , but he wasn't able to solve the problem. He did tell me the front head is firing, but not firing consistently. Going to pick it up today. As for a crack on the manifold, I can take a look at that. I know there is a crack on the front exhaust pipe. It's about 1 or 2 inches before it connects to the heads. Don't know if that could cause the engine to fire randomly.
 

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From the sound of what going on I would say inconsistent firing is most likely from carb malfunctioning, or Electrical Ignition issue. did you look at both spark plugs ? And ?

Some diagnostic work needs to be done to figure it out.

He may not have enough skills to figure it out. Time to find other help
or better mechanic.
 
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