Fuel Milage

[GilbertHall]

I recently bought a 1983 Venture 1200. I only get 25-28 miles per gallon. the previous owner sent it to Topeka Powersports for poor fuel mileage. They installed new Diaphragm assemblies. Is this milelage typical? or is something wrong? I have talked to two other venture riders, one on a poker run, and one @ the truck stop, and apparently fuel milelage is low. On the Venture history page, it states the average fuel mileage @ 42.5 mpg, it states the capacity @ 5.3 gallons, the owners manual says 5 quarts. The warning light came on and I put 3.92 gallons in. Trying to decide if another carb overhaul is warranted this winter?

Gilbert

[KiteSquid]

Just because the dealership replaced the diaphragms, does not mean they properly overhauled the carburetors.......

 

 

I would recommend a pint of Camp Fuel in the gas tank at your next refuel, and if that does not fix it, do a carburetor overhaul, with the help of a local VR member........

[V7Goose]

Your fuel mileage is way too low. Personally I would never put camp fuel in my gas tank, but there are several good fuel system cleaners that you can try, such as Techron, Sea Foam, or 44K.

 

But I'd look beyond the carbs for what is wrong. With that low mileage, I would not be surprised if you were running on only three cylinders. Read your plugs to see if they all look the same and check the heat on the header pipes right next to the head after only running for 30 seconds (one minute max). They should all be too hot to touch for more than a brief second.

Goose

[GilbertHall]

would you recommend clymer repair manuals? I'm not sure how to remove the the lower leg fairings to do the exhaust pipe touch or pull the plugs. there is no lack of power to be running on three cylinders. If the power I have is three cylinders, if I get #4 back, it should do a wheelie with the twist of the throttle.lol

[V7Goose]

I personally do not know much about the 1st gen bikes, but there are plenty on here who will jump in shortly and tell you all you need to know about what manuals are best and how to do the work.

 

But I can assure you that these bikes run really well on just three cylinders - it is hard to tell until you are pushing 85 MPH. Your problem could be either a completely dead cylinder or other things like bad plug wires that just make all of them run less than optimal. Of course, it might be a mechanical issue also, such as misadjusted valves or poor compression. But one step at a time. Keep us posted on what you find, and there are plenty of folks here that will help you eventually narrow it down.

Goose

Edited July 15, 2010 by V7Goose

[mike_kelly_68]

would you recommend clymer repair manuals? I'm not sure how to remove the the lower leg fairings to do the exhaust pipe touch or pull the plugs. there is no lack of power to be running on three cylinders. If the power I have is three cylinders, if I get #4 back, it should do a wheelie with the twist of the throttle.lol

 

 

These might help.

 

http://www.venturerider.org/forum/forumdisplay.php?f=90

[V7Goose]

FYI - I just noticed this thread was in the 2nd gen tech forum, so I moved it. Your bike is a 1st generation Venture. You will get lots more attention from the right people in this forum.

Goose

[utadventure]

would you recommend clymer repair manuals? I'm not sure how to remove the the lower leg fairings to do the exhaust pipe touch or pull the plugs. there is no lack of power to be running on three cylinders. If the power I have is three cylinders, if I get #4 back, it should do a wheelie with the twist of the throttle.lol

 

 

Remove the side panels and the chrome pieces right behind the radiator and you should have access to the exhaust pipes and can do the recommended touch test. This will also give you access to pull the lower faring if you need to.

 

I would also remove the air cleaner so you can see inside the carbs. Look to see if all four of the sliders are moving when you throttle up (I will probably run crappy during this observations because it will be getting too much air). If they don't all move, take a screwdriver and gentle pry the slider in a bit. It won't take much and they don't have to move very far.

 

Best of luck!!

[skydoc_17]

Hey Gilbert,

Welcome to VR.ORG! I think you will find all that you need as far as getting your bike running. First off, I would like to point out that you have posted your question in the "Second Generation" section. You have a "First Generation" Venture Royale. YOu will get more help if you post in the section that your bike belongs in. Just an FYI.

Here is a link to the Yamaha Repair Manual. You can download if for free. This Manual is much better than the Clymer books. V7Goose gave you some good info about checking to see if all 4 cylinders are functioning. I would also suggest a Carb. Sync. after you are sure you are running on all 4.

Next I suggest you find a VR.ORG member in your area, invite him over for lunch and learn a bit about working on your new to you VR yourself.

It will be fun, you will make a new friend, and you will save a ton of money doing the repairs yourself. If you have other questions, or need parts, please feel free to PM me.

Earl

[GilbertHall]

30 second run test, Rear cylinders hot, front cylinders warm. I pulled the front two plugs, one had raw gas on the threads. Even my wife said, "did you check the air filter?" A dirty air filter would cause all four to be flooded??? I will try removing the air filter and check the slides

[dingy]

Below is a link to a more complete manual than what is posted above.

 

The manual above is missing about 10 pages at various points throughout it.

 

Snaggletooth scanned the missing pages and I inserted them.

 

This manual covers 1983-1985 bikes.

 

http://www.venturerider.org/forum/showthread.php?t=43688

 

Gary

[GilbertHall]

All four carburetor slides are sliding. Going to concentrate on the ignition system, after I research the carbs (float circuit???) Seven circuits common to all carburetors. Choke, Float, Idle, part throttle, full throttle, full throttle full power and acceleration.

[CrazyHorse]

All four carburetor slides are sliding. Going to concentrate on the ignition system, after I research the carbs (float circuit???) Seven circuits common to all carburetors. Choke, Float, Idle, part throttle, full throttle, full throttle full power and acceleration.

On that model you should have adjustable needles with I think 5 adjustments. If it at it lowest setting you would only get the mileage your describing. I would check to see where your needles are set 1st.

[MasterGuns]

On that model you should have adjustable needles with I think 5 adjustments. If it at it lowest setting you would only get the mileage your describing. I would check to see where your needles are set 1st.

 

 

The above response leads me to this question.....Are the adjustable needles from an 83, 84 and 85 (I assume all had adjustable needles) interchangeable with the needles in an 86-93. Just curious. Sure would be easier adjusting the needles than adding then reducing washers and other improvised ways of adjusting fuel intake levels on the 86-93. Probably been asked before but what the heck.

[utadventure]

The above response leads me to this question.....Are the adjustable needles from an 83, 84 and 85 (I assume all had adjustable needles) interchangeable with the needles in an 86-93. Just curious. Sure would be easier adjusting the needles than adding then reducing washers and other improvised ways of adjusting fuel intake levels on the 86-93. Probably been asked before but what the heck.

 

The needles themselves may be interchangable but if I understand correctly the outside diameter of the sliders are different.

 

Dave

[GilbertHall]

I am assuming you guys are talking about the needle jet screw?

In the ignition system chapter, they suggest testing the spark with an Electro Tester. On an automobile, the spark tester makes the coil jump 1/4" gap. In the mean time I'll try some Sea Foam (being how I have some)

[utadventure]

The needle we're talking about is the needle in the end of the slider. It adjust the rich/lean status of the carb when you throttle up based on vacuum in each cylinder (carb).

 

It is the needle shown in the diagram and marked as part of #21. Diagram

 

Hope it helps!

 

Dave

[warthogcrewchief]

I had a problem with cylinders not firing... turned out it was two seperate issues: The first was the spark plug wires (cheap, quick fix). The second issue was the recently replaced (four months old) spark plugs. I had a plug that was bad! I had never seen that until this time. These plugs are a little finicky.

 

While you have everything off, you should test the four coils and the electronic control module. There are instructions listed on this site, but I forget where... I'll look around.

[GilbertHall]

Approximately 4 oz. of Sea Foam went into approx. 3.5 gallons of gasoline, and my mileage jumped to 30 mpg. Next, I'm trying more Sea Foam and two new front cylinder plugs. I too have installed bad, "new plugs". Keep it Simple, Stupid. If I can get it too 35 mpg, I'll be happy.

[GilbertHall]

The needle we're talking about is the needle in the end of the slider. It adjust the rich/lean status of the carb when you throttle up based on vacuum in each cylinder (carb).

 

It is the needle shown in the diagram and marked as part of #21. Diagram

 

Hope it helps!

 

Dave

 

Thread the needle in, lean. Thread the needle out, rich?

[Cruser]

I average 31.6 miles per gallon and feel like I should get more.

 

This has been a helpful thread.

[CdnDave77]

Thread the needle in, lean. Thread the needle out, rich?

 

Yes... what you are trying to do by lowering (or extending) the needle is to get it to stay in the main jet a little longer (the slider has to move further to get more fuel). And therefore the opposite is true too : raise (retract) the needle into the slider, it opens more of the main jet sooner.

 

You've probably heard it before but I will reiterate : Seafoam is great stuff, but it can screw up your plugs if you use too strong of a dosage. But, if it helps get your carbs back to 40+ mpg, a new set of plugs are quickly paid for.

[Cruser]

Do you guys think elevation effects the rich/lean settings ?

 

I think it does.

[CrazyHorse]

The above response leads me to this question.....Are the adjustable needles from an 83, 84 and 85 (I assume all had adjustable needles) interchangeable with the needles in an 86-93. Just curious. Sure would be easier adjusting the needles than adding then reducing washers and other improvised ways of adjusting fuel intake levels on the 86-93. Probably been asked before but what the heck.

 

 

I think they were adjustable in 83 and part of 84 only. I use the 83 style in my 1990 the 83 style have a much more aggressive taper at the end then the rest of the years. I could measure them and find out. When I was screwing with them at the richest setting I was only getting 25 mpg at the leanest with the lowered needle mod I get about 41

[GilbertHall]

Installed two new plugs in the front cylinders, 4 more oz. of Sea Foam. Performed the 30 sec. run test. Front two cylinders might have been a little warmer (my pyrometer fingers). Fuel gauge says half a tank (three bars)(it has to be a 4 gallon tank) Trip odometer is on 70. I'm gaining on the mpg. When I get real ambitious, I'll tweak on the slide needles.