HELP! First gen odd (to me) problem, advice PLEASE!!

[arbee_11]

 

When I was a lad I had a neighbor who had a first gen Venture, I loved that bike and told myself that someday I would have one. 24 years later I found and bought my Venture from a BMW dealer who had it stored in his garage in pristine (honestly like new) condition with an original 8500 miles on it, it was his personal bike before he got into BMW's and I cannot stress just how nice it is, but was it ever dusty! I drove it the 60 miles home and it purred like a kitten, shifted beautifully, wandered a bit on the highway (25lbs air in both front and back tires, who thinks to check that? oops) Anyway! I decided to take all the plastic off the bike, clean, polish, touch-up, change the battery, oil, filters, plugs, wires etc etc...

 

I spent an entire week, dawn to dusk on that bike, and when I was done, whoa! It looked like it just came off the showroom floor and I was very pleased, right up until I rode it.

 

Before I describe the problem, I wish to point out that I am not a mechanic, on a knowledge scale of 1 to 10 (ten being a pro mechanic) I am about a 3, when it comes to electrical, I am more like an 8 or 9.

 

The problem:

 

Ok, choke the engine and start, it fires before 2 revs, warm up engine and turn off choke. Hop on and and begin to ride, acceleration is very smooth, here is where the "issue" starts. Ok, as you accelerate to say 55mph, you go thru the gears and you reach that 55mph, at the very moment that you reach your speed you let off ever so slightly on the throttle and you feel the inertia of the bike meet the declining engine RPM, in other words you are no longer accelerating and you are not slowing either, it is at that very moment that the engine begins to bog or act as if it is starving for air or gas or spark or???? It continues to go down the road, only once has it backfired, one pop while moving out to pass a car. When I accelerate from the 55mph, there is a 1/2 second delay in throttle response, and for just a moment it seems to "chug" up to speed then accelerate smoothly and normally. Saturday night on the way home from work I tried an experiment, I had driven about 10 miles so engine was fully warm, I would accelerate and experience the above, so I cut in about 1/4" of the choke lever and it accelerated very smooth! It did not "cure" the problem, but made it 75% better..

 

With the exception of new plugs (I believe I gapped them properly) and wires, battery, oil and filters, I didn't even touch the engine or carbs, but maybe I dislodged a hose, or??? I don't know, I don't "see" anything out of the norm but this is making me crazy! PLEASE, if you have a suggestion or have experienced similar, I can sure use your advice.

 

Thank you muchly!

 

John

KB7VZL 73's

[Black Owl]

OK,

 

All together now.. SEAFOAM...... Throw a can of SeaFoam into a full tank of gas and literally Drive the S..T out of it.

 

Next.. Carb Sync.

 

These two actions together should correct 99% of the problem.

 

[KingSizer]

You'll probably hear this two dozen times...

If the bike was sitting for any extended length of time the old gas in the tank has probably done some clogging somewhere in the fuel system, including the carbs. Don't think you have to take the carbs apart and clean them,...yet.

Go to walmart or an autoparts store and buy a can of the ever famous SeaFoam, pour it in the tank, fill up with gas, kiss you wife good bye, and go on a nice little 150 mile ride in any direction. Be sure to crank it up every so often to blow out the carbon build up and any other junk that may need to be cleaned out. You might even see some smoke coming out of the pipes, don't be concerned. Seafoam is to carbs what an enema is to ********. Just make sure you don't ever put an enema in your tank and seafoam up your ***.

Good luck, I hope this helps, and enjoy your new scoot...

 

Todd

[SilvrT]

OK,

 

All together now.. SEAFOAM...... Throw a can of SeaFoam into a full tank of gas and literally Drive the S..T out of it.

 

Next.. Carb Sync.

 

These two actions together should correct 99% of the problem.

 

 

 

A great big DITTO

[arbee_11]

I am off to locate that Seafoam (interesting name) and give it a try, I looked on their web site, stuff looks like a miracle in a can. Fingers crossed and I will post the results. Thanks!

 

Johnnie

[GeorgeS]

Some NAPA stores carry the stuff.

 

Also check the Off brand Auto Parts places, Shucks does not carry it.

 

If you can't find sea foam, Most any Synthetic Fuel Injector Cleaner Also should work.

 

I would also suggest that you Completly Drain the Fuel Tank !!! Pull hose OFF at the Petcock, drain that last gallon out useing the Reserve position on the petcock.

 

Start with ALL NEW GAsoline !!!!!

[6m459]

I don't know that I'd put a whole can in a tank full but, at the concentration recommended by the mfg at 1 oz / Gal, SeaFoam certainly cheered up my old gal !

 

Brian H.

Uxbridge Ont

[Squidley]

I don't know that I'd put a whole can in a tank full but, at the concentration recommended by the mfg at 1 oz / Gal, SeaFoam certainly cheered up my old gal !

 

Brian H.

Uxbridge Ont

 

 

Just for info sake, many of the folks that have used the seafoam put a full can in the bike and fill the tank up. Then go out and run the tank out, I haven't heard of any ill effects and I know that it will help clean up the dirtiest fuel systems. Not saying for arguement sake just for info purposes

[SilvrT]

SeaFoam certainly cheered up my old gal !

 

 

 

hmmmmmmmmmm...... I wonder if this would work on......... (a particular "old gal" I know)

 

:rotf:

[utadventure]

I'll bet that the Seafoam resolves your issue but something else you might want to consider is the RPM's. If you're in 5th gear going 55 mph and trying to accelerate (especially hard acceration) you might bog down a little bit. Something that has been mentioned many times on this site is that these bikes really like and work better in the higher RPM range. I'm sure there are others here that can clarify it better but I believe it been said 4K and higher is best.

 

Another thing to be aware of is - many have modified thier airboxes to let a little more into the carbs. Again, something you may or may not consider.

 

Welcome to the best VR site on the web. These guys are great at helping you get past any issues you find.

 

Dave

[PBJ]

I am off to locate that Seafoam (interesting name) and give it a try, I looked on their web site, stuff looks like a miracle in a can. Fingers crossed and I will post the results. Thanks!

 

Johnnie

Also while your there it might not hurt to pick up a new furel filter. I'm surprised no one else mentioned this but it sounds like you might havwe a clogging filter that is restricting gas flow at higher speeds. Even if its not with all those years sitting , and probably not with a full tank ,rust in the tank is going to clog a filter eventually. So Seafoam and fuel filter should help alot.

[Gearhead]

I'd do the whole can of Seafoam....

 

If that doesn't do it...it's almost definitely in the carbs from sitting so long. Evaporated gas leaves this weird stuff behind called varnish. A couple other easy things are draining the tank as George recommended and cleaning out the fuel bowls, and it would be best to do these before the big Seafoam event. To clean the bowls, locate the bowl drain hoses right under the carbs. Hold a large, absorbent rag under one, open and open the drain for that bowl 2 or 3 turns. The fuel will come out. Now take a can of spray carb cleaner and, again holding the rag there, use the red spray tube and shoot that stuff up the drain hose, then let it drain back out. Do that several times and observe what sort of stuff comes out.

 

After that and Seafoam, if the problem persists, the carbs need to be torn down to clean properly. The other thing that comes to mind is the slide diaphragms. They get cracked and holed with age. I'm not sure if the low miles and garage storage prolongs their life or not. They're easy to check with the carbs on the bike. Just remove the round-ish cover with stripes on it that faces outward on each carb. Watch for the large spring and tiny o-ring. The diaphragms are right under there.

 

Your observations and description were very thorough and detailed, thanks. That helps. Also, I agree that these engines hit their stride between 3-4k rpm. However, they run nice and smoothly below that, too. You should not have hesitations, bucks or stumbles.

 

Jeremy

[KingSizer]

many have modified thier airboxes to let a little more into the carbs.

 

Dave

 

How do you do this???

 

 

 

 

also, I once had a KZ1000 that had old rubber fuel lines that had weakened and at higher rpm's the fuel line sucked in and collapsed and wouldn't let any gas through, causing the bike to bog down and stall like it was running out of gas (because technically it was). I put on new fuel lines and it solved that problem.

[utadventure]

The mod I read about involved drilling between 2-4 1/2" holes in the airbox to increase air into the box. I haven't personally tried this mod so I can't say whether it works or not. Hopefully, someone that has experience with the mod will chime in and let us both know the success and benefits.

 

Dave

[Gearhead]

Airbox mods are a good point. Not that you should NEED this to make is run right. Conversely, if there are TOO MANY extra holes in the airbox lid that can cause problems. These bikes in their stock state carb tune are very sensitive to the airbox configuration. If you remove the airbox lid and then start the engine, most find that the bike will idle but won't take any throttle.

 

I have (4) 9/16" holes in my lid (airbox, that is) and I really don't think it made much difference one way or another.

 

Jeremy

[arbee_11]

I am going to postpone using it; After reading all your replies and a couple private msg's. I am going to follow several suggestions. One BIGGIE that I found, while putting tools away, there in the bottom of the toolbox was the FUEL FILTER that I had intended to install but spaced it, I had a look at the current filter and noted how dark it is, so MAYBE the plugged filter post might be the culprit, but I am going to do all the other suggestions too. I'm 'a learnin...

 

Thanks all, will keep you posted..

 

Johnnie

(Keizer/Salem Oregon, where we ride for three months and drown the other nine)

[BradT]

I don't know that I'd put a whole can in a tank full but, at the concentration recommended by the mfg at 1 oz / Gal, SeaFoam certainly cheered up my old gal !

 

Brian H.

Uxbridge Ont

 

Must have spoke to the same person as I did. THis is what I was told as well and seems to stil work.

 

 

Just for info sake, many of the folks that have used the seafoam put a full can in the bike and fill the tank up. Then go out and run the tank out, I haven't heard of any ill effects and I know that it will help clean up the dirtiest fuel systems. Not saying for arguement sake just for info purposes

 

 

No side effects but it may not be needed either. One can should be able to two tanks in this case, which may be better than one whole can for one tank.

 

You could also put it in the tank run for a bit to make sure it is in the carbs then let it sit for a day then run it hard and burn the rest of the gas up

 

BRad