Running Really Rough All of the Sudden

[davidon]

Patrick

You're in my neck of the woods..if you need someone else to look at it let me know.

 

[Patrick78]

Patrick

You're in my neck of the woods..if you need someone else to look at it let me know.

My dad actually lives in Clarksburg so I'm in Md fairly often. You wouldn't happen to have the Carb Sync tool that I could borrow do you?

 

[gamorg02]

if u need a carb synch tool, mines on its way to Massena NY and could be shipped there afterwards.

 

[Patrick78]

if u need a carb synch tool, mines on its way to Massena NY and could be shipped there afterwards.

Yes Please! That timing may actually work perfectly in conjunction with the previous owner mailing me back all the stock carb jets, needles and springs. So then I could get everything done at one time.

THANK YOU.

 

[gamorg02]

Yes Please! That timing may actually work perfectly in conjunction with the previous owner mailing me back all the stock carb jets, needles and springs. So then I could get everything done at one time.

THANK YOU.

oh no problem. I'll touch base with kyle (kaboom) when he gets it. its only a 2 port model, so it takes a bit longer, but works perfect.

 

[Patrick78]

So I got home today and it was nice out so I thought I would test the bike to see if it would start up since I was having so much trouble with it over the weekend. It fired right up the first time, but man it is still rough. Much worse when its cold. There is definitely two different sounds coming out the mufflers. Once it warms up and I can close the choke it does smooth out, but its still rough. It has a slight surge to it, you can see if in the tach needle. It sits right at 1k rpm, but it moves up and down with the surging sound of the motor and this is something that it's never done before. When I blip the throttle while in neutral there is a loud cracking sound from the right muffler that doesn't come out of the left.
So what do you guys think could cause this? And my other question has to do specifically with the idle mixture screw on the carbs. What exactly does this do and how do you adjust it to make sure its right? I had to take these out when doing the Shotgun and I tried to turn them in and get a count so I knew how far to back them out when I reinstalled them, but I think I was getting an inaccurate count because the little springs were seized up with crusty crap so I wasn't getting a consistent feel to the screws as I was turning them in. Is there a thread somewhere that explains how to adjust these or can that be done during the carb sync process? I obviously don't know a whole lot about carbs or exactly how they work. I can follow instructions well so I usually do well following people's tutorials or how to's. So if there's one out there, let me know.

 

[dannymax]

Patrick, just set them at 2 1/2 turns out from seating....that'll put you close enough.

 

[Patrick78]

Patrick, just set them at 2 1/2 turns out from seating....that'll put you close enough.

Ok I'll give that a shot and see how that goes. The instructions in the Shotgun how to tells you to screw them in until they seat but he was very specific about doing it GENTLY. Do I screw them in until it completely stops turning or just until you feel the tension on the spring thats behind the head of the screw?

I think thats where I might be messing up. I'm too worried about over tightening them.

 

[dannymax]

Ok I'll give that a shot and see how that goes. The instructions in the Shotgun how to tells you to screw them in until they seat but he was very specific about doing it GENTLY. Do I screw them in until it completely stops turning or just until you feel the tension on the spring thats behind the head of the screw?

I think thats where I might be messing up. I'm too worried about over tightening them.

Lube the screws up good, so it screws in smoothly and you will feel when it stops. It will go several turns after you feel the screw make contact with the spring.

 

[RaWarrior]

Since you're saying there seems to be different sounds from each muffler, maybe it's dropping a cylinder at idle? Use a spark tester on the cold bike, hook up all 4 wires and crank it. Some auto stores rent these, one near me does. It will be obvious if one isn't firing at all, and if you watch carefully for a couple seconds you should be able to tell if it's intermittent or randomly firing.

Working on outboards I've seen a bunch of cases where the motor runs like crap and everyone instantly blames the carbs, when it turns out to be faulty/dying ignition system components. Ignition components tend to have very short lives on outboards, espically older Mercs from the 70's. Might be worth checking out, always good to look at different angles of the problem.

 

[Patrick78]

I've never heard of a "spark tester" before. Is that the actual name of the tool? I'll see if the local parts store rents them, but just wanted to make sure I'm calling it the right then when I ask.

 

[Patrick78]

Ok well I screwed all the idle screws in and turned them out to 2-1/2. They were all out way more then 2-1/2. I must not have screwed them in all the way when I reinstalled them after the shotgun.
But that didn't fix the problem either. The bike fired up and is still about 3 times louder out of the right hand muffler then it is out of the left. I guess I'll see if I can find this spark tester to see if I'm having an issue with ignition next.

 

[dannymax]

Start it up cold start & check your pipes to see if one isn't warming up like the rest....just be careful, they heat up fast!

 

[twistedmax]

Start it up cold start & check your pipes to see if one isn't warming up like the rest....just be careful, they heat up fast!

if you dont want to touch it..... you could buy a infer red temp gun ,there not real expensive.

 

[Nicki66]

Start it up cold start & check your pipes to see if one isn't warming up like the rest....just be careful, they heat up fast!

I must add a word of caution about doing this when you have stainless pipes. You can very easily leave a oily hand print on your pipes that you wont notice until it cooks into it. Don't ask how I know.

 

[EAGLEPI]

I had sleeves made for my cans and use cloth to cover rest of pipes.. but that was when I was riding my VMAX

 

[Patrick78]

I shot an email to the PO just to see if he had an opinion on what the issue could be since he had the bike longer then I have. He's a mechanic as well so I thought it could be a good source. Anyway, he stated that the Vmax carbs can be sensitive and easily become out of sync, but more importantly he did say that he recalled a time that one of the coil wires had come loose at the coil. He didn't recall which one but did remember it being under the seat. So I guess that gives me something decent to look at first.
I'm been watching some ebay auctions and I'm pretty sure I'm going to go with some R1 COPs now as it may kill two birds with one stone.