Rough running Bike

[TheKid]

I can crank the bike up with full choke and it will warm up fine but with a lot of popping. I push the choke in and it slows down, pops a lot and then cuts off. When I give it gas it will rev up but not hitting on all four cylinders. I have checked the plugs they were just replaced not even 8500 miles ago. The carbs were cleaned also at that same time. I also replaced the fuel pump because it went bad at that same time as well. I have ran sea foam through it also. I am thinking the carbs are out of adjustment real bad. Does anyone have any suggestions on what else might be wrong. My mechanice is 3.5 hours away and I really don't want to have to trailer it all the way down there if I can work on it here at my house in my garage.

 

Thanks for all the help in advance.

 

Robert 'TheKid'

[Eddie Fulmer]

Just a thought. You might try looseing the drain screws on the carbs. I did that and some water came out of one of them. You most likely have a lean condition there. That will also tell you if you have gas in all carbs. After the water was removed the bike ran great. Just a start. Remember gas is made to explode. be safe.

[TheKid]

Thanks I will try that. It has to have something to do with the gas system or carbs I think.

[TheKid]

I have drained the carbs and there was fuel in all four bowls. I have rain sea foam through the gas. I have also drained the tank and added new 93 oct with sea foam in it.

 

The fuel pump is working and clicked a lot once the bowls were drained. Turned the bike off and it click a few times then stopped. Turned of and back on. Started with chock full out and ran real rough for few mins. Then I pushed the choke in and it idle real rough. Gave it gas and it sputtered real back and cut off. It is not firing on all cylinders and I can hear that. It sounds like it is getting the air but no gas to two cylinders. It cuts off when giving it gas.

 

I have checked the plugs and they look good, they were replaced not even 8000 miles ago.

 

I don't know what else to do other than check and see if the carbs are aligned. Would that make a difference?

 

What other advice do y'all have?

 

Thanks for all the help.

 

PS: I have read through a lot of the posts about carbs and I have tried almost everything that has been mentioned.

[LilBeaver]

Just as a warning here, I am certainly no expert when it comes to carbs or this stuff, I am not a professional mechanic by any means (nor do I pretend to be) and I did not stay at a holiday inn express last night... But I'll offer a few thoughts as maybe something might help...

 

A few things come to mind:

 

First of all: You said that the carbs were cleaned less than 8500 miles ago and the plugs were changed at the same time. was there something wrong with performance or the carbs at that time? How long ago was that and how often was the bike run in between those times? How much time has passed since the bike ran well and the current behavior (was there a time that the bike sat?)?

 

The book has an 8,000 mile change interval on plugs (I believe) so if you are close to 8k since the last plug change, that could be an easy check.

 

Next: If you do have a passage that is completely plugged in the carbs, you could run all the seafoam in the world through it and it wouldn't help; so if you do have a fuel delivery problem (caused by a blocked passage in the carb) cleaning the carbs is probably the next thing. But pulling the cabrs off and checking for proper setting and positioning of floats, jets, etc could also be benificial here. Before you pull those puppies off I do have a few other ideas or things to check out (if you have not done so already; my apologies if you have already done any of the following but here they are anyway)

 

Running with pops while choked and then hardly running while at idle could certainly be a caburator problem and that may be the way to go. However, something else to check is to see if you are getting fuel all cyliders at all and also to ensure that you are getting spark to all of the cyliders. I know that you said that you pulled the plugs and they look fine but here is an idea (if you have not done it yet).

- Pull the plugs and clean them with a wire brush, gap them appropriately then put them back in

- Crank the motor (with the choke fully in) but do not start the engine (ie turn it over a few times)

- Pull the plugs (noting which one came out of which cylinder, of course) and look at them again while also smelling very carefully to see if you smell any of them with an overwhelming fuel smell. Also carefully inspect each one to see if they all look the same. If any of them look different, note which one(s) appear different and compare them to pictures (or a vehicle that you know is running fine) to see if you can determine whether you are actually getting fuel and combustion at that particular cylinder.

- While you have the caps off of the plugs, I would go ahead and pull the ends of the caps off and check and clean the little spring inside each cap. Some of us have found that those get heavily corroded and inhibit the ability to deliver the appropriate spark to actually fire properly. (Goose has a real nice write up on this in the tech section, by the way).

 

 

Oh yea, something else to do to determine which cylider is not firing (if that is the case) is to start it up (cold) and while warming up, monitor the temperature of each exhaust pipe as it comes right out of the motor. If any of them are colder than the others then you have identified a cylinder that is either not firing due to an ignition problem or a fuel delivery problem (well, fuel-air mixture delivery problem that is).

 

Some folks have had some luck with filling the carbs with straight up seafoam and letting it sit over night (by draining the carbs, turning the fuel off, then running the hose that goes through the fuel pump and into the carbs into a bottle of seafoam and letting the fuel pump suck some seafoam into the system). I do maintain that if you have an idle passage that is 100% blocked this will probably not be helpful, but who knows - :shrugs:

 

Some other thoughts are things like make sure that the vacuum caps/hoses and whatnot on the carbs are all run to the right places and that the caps seal properly.

 

 

Sorry you are having trouble friend, and sorry that this probably isn't much help. Hopefully someone else can chime in with some more useful information/guidance.

 

Edited January 20, 2010 by LilBeaver
Re-read initial post and realized I had missed a few key things...

[KiteSquid]

are any of the spark plug wires crossed??

 

E.g.: are wires for #1 and #2 cylinders on the wrong cylinder?

[TheKid]

Thanks for the help. First the spark plug wires are not crossed. Second the bike doesn't sit long at all the longest it has sat is probably a week or two when I was sick and it was real cold in the teens.

 

Reasons the crabs were cleaned last time is because of almost the same issue. the bike would run of full choke but once you push the choke in it cut off. The mechanic said there was a lot of corrosion dues to bad gas and having around 30K miles on the bike at the time. I thought it was a little strange but hey I am no mechanic.

 

Once the carbs were cleaned I took a 7000 mile ride out to Sturgis, Wy, and back. Then the bike sat for maybe a week and rode a little here and there. Then the bike now has been sitting for maybe two weeks because I was sick. The battery died so I replaced it, forgot to hook up the battery tender and it got to cold.

 

I did not know that the book says change the plugs every 8k so maybe I should do that again, even tho the plugs looked good.

 

I also know i need to change the oil but want to warm up the bike to do that so the oil drains a better.

 

I have a feeling all the carbs are getting gas though because when i drained them last night each one had a good significant amount of gas in them.

 

Steps I will take to see if they work.

1. Check plugs and or replace them all

2. Clean all connections

3. Check temp of the pipes when running from cold start.

 

I am def not a mechanic so pulling the carbs I reckon is out of the picture and I would have to trailer it to a mechanic that I trust, to bad they are 3.5 hours east of me. Hopefully if it is a carb issue I can talk them into making it a warranty case. I don't think I should be having carb issues already when the bike barely sits still and only had like 45K+ miles on it and it was bought in Late 07.

 

Thanks for all the help guys, I will keep you posted.

[Mel]

For what it's worth------- if the fuel tank is dirty or contaminated you can clean the carbs and fuel pump forever but they will get clogged up again. I had this problem on my '84 VR, had the tank cleaned and some kind of coating applied along with the carbs being cleaned and the problem was gone.

 

Mel

[Condor]

It's still under warantee. Take it to a dealer....??

[Sleeperhawk]

If it is under Warrenty, and you are going to trailer it, then take it to Extreme Sports in Sumter, SC, about 2 hours from Charlotte, family owned Yamaha place that I have no problem taking my bike to for warrenty work or something I could not handle.

[Kirby]

You might want to pull each plug, insert sparkplug back into the cap, and ground each one against the motor and bump the starter(not enough to crank the motor) and watch the plugs to see if they each are actually producing a good spark. If one is not sparking, it should be wet with gas. If you find one not sparking, pull the plug out of the cap and stick a small screwdriver or something with an insulated handle up inside of the sparkplug cap(be careful not to damaged the clip that snaps onto the small end of the sparkplug). Then holding the insulated end of the screwdriver, hold the bare part of the screwdriver about 1/8-1/4 inch from the engine cylinder fin or a grounded part of the engine. Bump the starter again and watch to see if the sparkplug wire itself is producing a good spark. If it is, then you've probaly got a sparkplug problem. Clean, regap, and recheck.Do this for each sparkplug and you will be able to narrow down your problem. There's much more to check but this will get you started. There are basically 3 things to make an engine run.., fuel, compression, and ignition. I have always tried to check ignition(spark) first. Someone else here may go into the more detailed ignition problems. Hope this helps.

[Cougar]

Just for the heck of it. have you tried taking you fuel cap off to hear if it

makes a swish sound? and maybe your vent is clogged? Just a simple thing

to look at, As I had this happen 2 years ago. and my bike would just die out

on me. come to find out the whole time my vent was rusted closed.

Drove my crazy

probably not it, but worth a simple check. run the bike with out the cap on

for a few.

Jeff

[VegasVic]

my number 3 cyl. wasn't firing, and if I drizzled gas into it at idle it would fire. So, had a mechanic friend pull and clean carbs, adjust valves and now bike is running on all 4 again.

When you start up your bike, put your finger on the exhaust pipe near the cyl. head to see if it is getting hot. Be careful, they get hot quick. If you find one or more, that stay cold, you know which cylinder is not firing. Then you need to check for spark, if you have spark, it will be a carb problem.

[Chaharly]

Whenever my Fuel Injected Tempo wont fire on all pistons, i usually just run it at highway RPM's until the problem either gets worse, or solves itself!

[Cougar]

Did you OR have you got any closer to figuring out what the problem might be yet?

 

Jeff