Low Power

[spotsy]

I have a 99 2nd generation and about a month ago I was riding in some of the hills of West Va and it almost felt like the power was not up to par. Then I convinced myself, yep it's fine. Then I noticed one other time that going up a hill it just seemed down on power since I had to roll the throttle all the way up and it was slowly picking speed. I'm thinking, was the hill steeper than I thought. Once again I convinced myself after a few miles all was good. Mileage is still the same so no change there. Last week I ran it up to about 95 on the interstate with no problems.

 

Yesterday the wife and I went for a ride about a 130 miles in the ride I noticed it felt like it was running out of gas and it was about due so I switched to reserve. Stop at the next exit and as I was taking off from the stop sign it felt like there was not enough fuel going to the carb's. Like I was trying to take off in second. I fueled up and switched back to normal. As we got back on the interstate I noticed it did not have the power that it should. No doubt about it this time. It was not missing and appeared and felt like all cylinders were firing. Up and over a mountain on the interstate in slowed down to about 55 mph and that's all she would do. On that mountain I would normally be at 70 or better going over the top with more throttle. I headed back to the house and figured when I got home, first thing to try was see how much gas was coming through the line and see if the fuel pump was running. For the 100 or so miles home the bike ran fine just did not have the power. It did backfire through the exhaust as I slowed down at several stop signs and I was figuring it was not getting the proper fuel.

 

About 5 miles before the house my wife said it's running better isn't it. Yep, sure is. Get home and all is good. Ran it through the gears and no problems.

 

Not sure where to start since no lights or anything. Now the bike is fine until it happens again.

 

Question, has anyone had this happen before? If the pump was to quit working any idea what systoms you would get? Would it quit all together or would gravity give enough fuel to make it run and act like low power.

 

As usual, any suggestions would be appreciated. Thanks.

 

Spotsy

[Steve S]

Spotsy,

My first thought is the fuel filter needs changing. If you have already done that and it didn't change anything, check the milage on the plugs. And then of course there is the fuel pump. It could be pumping, just not enough volume to keep you going under a load.

 

I'm sure others will come in with some really good ideas, but those are the first ones I would look at.

[spotsy]

Thanks Steve. I just changed the filter and plugs over the winter. Been about 3000 to 4000 since then.

 

Rider Duke had Muffin man give me a call and we figure the best place to start would be the tank and another new filter. I also plan on putting a test light on the pump and running the wires up top so I can tell when the pump is getting power and putting some dieelectric grease on the pump wires. Maybe something has happened with the pick up but I doubt it. Time will tell. It's at times like this you wish it would go ahead and wuit so you can find the problem. :-)

 

I just need to check the simple things to start with and was asking before I started that. Thanks for the suggestion.

 

Spotsy

[Redneck]

The symptoms do not act like fuel stavation. If you were not getting enough fuel to the carbs the engine would just die. If your filter was plugged or the fuel pump was not pumping enough the symptoms would be idle fine and run out and die under heavy throttle. It is possible that you have one carb starving from a stuck or pluged float valve. Open the drains on all carbs then turn on the key check the flow comeing from each carb. they should all be runnung a stream of fuel. The symptoms you describe could be a bad coil except for the no loss of fuel mileage. If it is possible when it starts running bad stop and pull all the spark plugs if you find a wet one replace that coil. When the coil fails it may still fire the plug with it out but won't fire it under load.

[Guest Saddletramp]

Could you possibly be carboned up? If your AIS is still functional try some "ring free" available at your dealer. Expensive but it will free up any carbon deposits in the combustion chamber.

[BoomerCPO]

Last year my Venture was doing exactly as you described. We discovered a weak coil was the problem. Found a wet plug on the right-side rear cylinder.Yamaha ate the Bill for the coil and a new plug too.

 

Boomer.....who knows the Venture will still run like a scalded ape on 3 cylinders.

[spotsy]

Thanks to all that replied. Right now i plan on checking the petcock and see how much fuel is pumped. Then change the filter which I doubt is the problem since I changed it a few months ago. I will check the connections on the ruel pump and put some di-electric grease there.

 

I see several have made comments about the coil's. I work on vehicles all my life however whenever there has been a coil issue you had a miss. Is it possible to have a bad coil and the bike not miss?

 

The next time it happens I hope to be able to pull the tank and the plugs to see if any of the plugs are wet. Once again thanks to all.

 

Now let me search for some coil posts problems.

 

Spotsy

[Redneck]

On the rsv it is possible to have a miss and not realize it.

[BuddyRich]

Check your air filters. Don't ask me how I know this.

 

Mike, I sure felt mine when it started to miss.

[Yammer Dan]

What Redneck said. These V-4's can miss and you have a hard time telling it.

 

And like Boomer said run like a scalded Ape on Three.

 

Just how does a Scalded Ape run anyway? Believe my 1st Gen could take him....

[BoomerCPO]

What Redneck said. These V-4's can miss and you have a hard time telling it.

 

And like Boomer said run like a scalded Ape on Three.

 

Just how does a Scalded Ape run anyway? Believe my 1st Gen could take him....

 

In the interest of maintaining a sensible blood pressure for certain members of this Forum I will not respond with any comments regarding the performance,parentage,or lineage of the 1st Gen motorcycle..........

 

Boomer.........who could be up for Sainthood if he can keep this up.

[Yammer Dan]

In the interest of maintaining a sensible blood pressure for certain members of this Forum I will not respond with any comments regarding the performance,parentage,or lineage of the 1st Gen motorcycle..........

 

Boomer.........who could be up for Sainthood if he can keep this up.

 

 

YAMMER ....... Who wonders what Boomer is trying to keep up???

[spotsy]

Okay, I started out by putting the fuel line in a can and starting the bike up and it's pumping plenty of fuel. Went ahead and pulled the filter and replaced it. Drained the tank and checked for water, no water. A few little specks of crud but nothing out of the norm. Pull the petcock and it was clean. Pulled the plugs and all look good however the two front one's are a tad bit cleaner than the back two. Pulled the ignition switch off and check that and did not see anything. Cleaned the bottom and regreased and reinstalled. Like soneone else said, I unplugged the pump and without rerouting the lines I'm convinced the fuel is not the problem. Some as I unplugged that the bike will shut down once the carbs run out.

 

As for air filters, I have the K & N's and I just cleaned and reoiled them a couple months ago. I pulled one side and it looked fine so I didn't bother with the other side.

 

On Friday I will get it all back together and ride it for a while. Hard to fix if it ain't broke. I'm sure it will rear it's ugly head again.

 

Spotsy

Edited June 25, 2009 by spotsy
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[Cutty]

I would definitly check the side where the two plugs that wasn't as clean. Maybe the air filters are OVER OILED, clean them again and test ride with no oil on them. Check inlets for blocked passages. Install two new plugs for the hell of it.

[spotsy]

I went through and changed the filter, cleaned everything, checked the plugs and put it back together. I started up the raod and right away this time I could feel a miss. Then it wouldn't miss but was low on power. I stopped and pulled the right rear plug wire and left it off and as soon as I tried to take off it stalled. Put that one on and then did the left rear. I was able to take off and it rode pretty much the way it was last week. I guess when I left to house is was hitting some and that made me feel the miss. Just wouldn't have thought that it would run that smooth last week and not be able to feel a miss. I know Redneck and several said it could be a coil. Good assumption.

 

So left rear is missing and I'll assume it's the coil since a lot have had problems with that. That's easier than pulling the carbs off. I will see if anything drains out the carb today to verify.

 

Anything else I can check?

 

Spotsy

[Cutty]

Try REPLACING the plug, cheaoer than a coil.

[spotsy]

Thanks for the suggestion Cutty. I had already done that. :-)

 

Spotsy

[Monsta]

You say you fueled up in your first post. Prior to that had you fueled up at a station that you typically do not frequent?

 

Given that the symptoms disappeared I would look more at the gas quality than any mechanical problem.

[spotsy]

A follow up to my low power post.

 

Sorry it's been so long however I did order a set of coils from one of the junk yards and about the the time they came in I went in for a hernia repair. Not fun.

 

Well, since I was off today and feeling better it's about time to install the coil. I installed the left rear coil and started the bike up and there was no difference. I scratched the ole pumkin and said I know that's what it was. Then after the bike cool down I realized ole dummy had actually replaced the right rear coil and not the left rear. Things are backwards once you remove them from the bike. LOL So I have now replaced the left rear coil and all seems pretty good as far as I can tell. Another couple weeks before the surgery will let me ride again but the engine does not have the back fire any longer so I'm sure that was it.

 

Lessons learned, When you think things aren't running exactly right, then chances are they are not right. When many on here say check the coils, then check the dang coils. On a 4 cylinder with a carb for each cylinder, it's possible to have a miss and not realize it.

 

Been working on engines for 30 years and never would have thought I could have a dead cylinder and not feel it. :-)

 

Thanks to all that provided assistance.

 

Spotsy

[Cougar]

Yep mine was the inward coil as well. bike runs

great now! this just happened to me as well last

month. $24.95 at pinwall for all (4) coils. now I

gots spares I thought I was going crazy:think:

I did all the filter stuff , plugs , air filter yadda yadda

nothing helped. weak coil was it. also, bench

test will not tell you a thing when they are cold. what I think

is that the inward coil is getting way to HOT! from the engine

and ya get all that water on it, also the wiring faces to the bottom

of the bike. These Darn bikes run pretty good on three cyl.

don't they? *lol*

Jeff

[Seaking]

Yep mine was the inward coil as well. bike runs

great now! this just happened to me as well last

month. $24.95 at pinwall for all (4) coils. now I

gots spares I thought I was going crazy:think:

I did all the filter stuff , plugs , air filter yadda yadda

nothing helped. weak coil was it. also, bench

test will not tell you a thing when they are cold. what I think

is that the inward coil is getting way to HOT! from the engine

and ya get all that water on it, also the wiring faces to the bottom

of the bike. These Darn bikes run pretty good on three cyl.

don't they? *lol*

Jeff

 

do you have the URL and P# for those coils? I'm going to be doing the oil, filters and plugs this week to hopefully remedy an issue, but if that fails, I'm willing to part with 30 odd bucks for coils.. can't hurt, good price.. ?

[Cougar]

http://stores.shop.ebay.com/PinWall-Cycle-Parts-Inc_Yamaha-Venture-Royal-Star?_fsub=5820835&_sid=12458664&_trksid=p4634.c0.m14&_pgn=1