help me troubleshoot my '87

[nateo]

Long story short, the engine idles a little rough, has poor power and won't run without the choke on. It'll idle with the choke off, but it dies when you try to take off.

 

Had the bike sitting in storage for about 2 years. Gas was untreated. It didn't run at all when I started working on it.

 

Here's what I've done:

I thought it was bad gas, so i drained the tank and fuel lines/pump/filter. Put it back together with fresh gas. Sprayed a ton of Thrust and Deep Creep into the carb and it runs now. Put Seafoam into the carb, and into the fuel tank, which helped the idle a very small amount, but didn't make a big difference.

 

I did notice that one carb moves more than the other ones.

 

Any advice on what I should do next?

 

I'm not 100% sure if the carbs were varnished, and if they were varnished, if they're cleaned out now.

 

Is there a way to check if the carb is clean enough?

Should I sync the carbs if they may be partially varnished, or is that a waste of time?

[RandyR]

The path of least resistance is to ride it a while (even if you have to use a little choke) with a good dose of Seafoam. It might take a couple tank fulls to clean things out, if you're lucky.

[83VR3711]

Have you checked the diaphrams yet? If they have holes in them, she will run terrible.

[Venturous Randy]

Have you changed the spark plugs and caps? These bikes are very sensitive to spark plugs that have had a lot of Sea Foam and stuff on them. Are all the exhaust pipes about the same temp after it has been running for a minute or so?

Yes, check the sync if you can and as noted, check the diaphragms.

RandyA

[Yammer Dan]

Sea-Foam soak.

[skydoc_17]

Hey Nate,

Welcome to the forum. Try this first, Start bike with choke, let it warm up, on the left side of the bike as you sit on it, there is the Idle Adjust Thumb Screw,(see pic below) Rotate the screw clockwise with your left hand and raise the RPM's. Turn off the choke, and check the tach. keep adjusting the thumb screw until you get 1000 RPMS with the choke off. If the bike will run now with the choke off load the gas tank with seafoam, and go for a long ride, run the RPM's up to 6000 in the lower gears and if you are going to be on the highway, leave it in 4th gear for a while. The object is to force as much of the seafoam thru the jets as you can and chugging along at 55 MPH in 5th gear ain't gonna get er done! Do this for 3 days in a row, gas up with the seafoam, ride it like you stole it, let it sit over night and the seafoam will do it's magic and then do it again! Keep the gas tank full, and keep adding the seafoam. ( the can says 1 oz. per gallon, I go a little heavier that that) After the three days, put in a fresh set of plugs, ease up on the seafoam for a tank or two and still drive the hell out of it! At this point if you are getting bad gas milage, or it still won't run, then we can start to check out some things. If you have questions, PM me, I been thru this quite a few times and this pretty much normal for a bike that has been sitting for a while.

Good luck, and don't be afraid to rev that puppy up!

Earl

[nateo]

Wow, thanks for all the great replies.

I'll try your suggestions and let you know what happens.

I really appreciate it, guys.

[utadventure]

You do what these guys have suggested and you'll have it ready to ride for the Cody Roundup in September!!

 

Welcome to the site - if you have a problem, someone here (usually multiple someones) has the answer.

 

Dave

[GeorgeS]

Also, Each Carb, has a drain hose, Find the #2 Allen head screw, that opens the drain on each carb. As you do the SEA - FOAM runs for 3 days, every night Open those drains, to drain out the bowls. ( well, do it at least once !! )

 

Next week, Sync the carbs!!! ( after the new plugs are installed )

[nateo]

I was checking out the carb pressure with the 2 bottle/fluid method, and found that the rear left carb (#1?) is totally out of whack. I think it has not nearly enough pressure, but it may be way too much.

 

The other carbs relative to the front left have pretty similar vacuum on them.

 

What would cause #1 to have no pressure?

[GaryZ]

Sea-Foam soak.

 

I agree. Put SeaFoam in your gas tank and drive around for a few miles to let it get mixed up. Park the bike overnight and let the SeaFoam work. I have also successfully cleaned up the idle circuit by removing the air-horn screws and shooting Berryman carb cleaner into the ports using the red plastic straw. Remember, before removing these screws, turn them all the way in and count the turns (write it down). After shooting the cleaner you can re-install the screws to their original setting.

 

The idle circuit is critical for not just idle, but any steady throttle below 2500 rpm. And the idle circuit is the most susceptible to clogging.

[GaryZ]

I did notice that one carb moves more than the other ones.

 

 

All slides should move about the same amount when you rev the engine. The slides that do not move much will likely have split or leaking diaphragms. Bad diaphragms will not allow the bike to rev past maybe 4000 rpm.

[skydoc_17]

Hey Nate,

I would like to address your comment about the #1 Cylinder you made earlier. When you do a Carb. Sync. You use a tool called a manometer which measures Vacuum (suction).

On our Ventures, the #2 cylinder (left front) is the master. All of the other Carbs. are set to this Carb. When you adjust screw "A" ( left side of bike, see pic below) you are ACTUALLY BALLANCING the available vacuum BETWEEN Carb. #2 and Carb. #1. If Cylinder #1 is higher (more fluid in your homemade Manometer) then turn screw "A" counter clockwise and lower the fluid level to match Cylinder #2. If Cylinder #2 is higher then turn Screw "A" clockwise.

When you have Cylinder #2 and Cylinder #1 BALLANCED, go to the other side of the bike and ballance Cylinder #3 to Cylinder #4 using Screw "B" (right side of bike, see pic below)

When Cylinder #3 is BALLANCED to Cylinder #4, use your Manometer to ballance the right side of the engine (Cylinder #4) to the left side of the engine (Cylinder #2) using screw "C" ( right side of bike, see pic below)

In other words, if any one Cylinder is higher or lower then the rest of them, use Screws "A", "B" or "C" to BALLANCE them untill they are all equal.

Use small adjustments and after an adjustment, "blip" the throttle a time or two to get the engine to accept the adjustment.

If anyone has any questions, PM me, I love to help!

Earl

[Dano]

I love to help!

Earl

 

 

Hey Earl, I got some siding to hang, gutters to clean out and a garage to straighten up. You interested?!!!!!

[skydoc_17]

Now Dano,

Don't make me come up there and install that fuse box upgrade kit you bought, I bet it's still sittin' in the bag!!! You Electricians are all the same! (My brother is one!)

Earl

[Dano]

Nah, got that done the next weekend. It involves the bike, ya know! It's the crap around the house I need a :buttkick:to get going on!

 

Dan

[calperin]

I had the same problem when I bought my 84.

 

Only one solution:

 

SEAFOAM

[MasterGuns]

After reading this thread, I am curious about what Nateo wrote, i.e, one slide with much more activity than the other three. Would the one slide with more movement be indicative of a problem or are the three slides with lessor movement the problem? I know all four should show about the same movement but when one is more than the other three, where does one look?

[GaryZ]

After reading this thread, I am curious about what Nateo wrote, i.e, one slide with much more activity than the other three. Would the one slide with more movement be indicative of a problem or are the three slides with lessor movement the problem? I know all four should show about the same movement but when one is more than the other three, where does one look?

 

From #12 of this thread;

"All slides should move about the same amount when you rev the engine. The slides that do not move much will likely have split or leaking diaphragms. Bad diaphragms will not allow the bike to rev past maybe 4000 rpm."

[Dano]

Start with synching the carbs first. That adjusts the butterfly in the carb throat. This controls vacuum. Next would be to pull the diaphragm covers, inspect for the little o-ring down at the bottom. Next would be to make sure the vacuum passages are clear by spraying carb cleaner in those passages. Pull the diaphragms and make sure the sliders are moving freely and not sticking. Make sure there are no vacuum leaks around the carb boots.

That'll be a good start.

 

Dan

[RandyR]

I don't think there's much point in syncing the carbs until they've had enough seafoam run thru them to dissolve any gum built up on the jets and seats. Otherwise you'll just be doing it again soon. Likewise, gum could be hanging up the slides a bit.

[Dano]

I don't think there's much point in syncing the carbs until they've had enough seafoam run thru them to dissolve any gum built up on the jets and seats. Otherwise you'll just be doing it again soon. Likewise, gum could be hanging up the slides a bit.

 

 

Seafoam will not access the port that pulls the vacuum to the rear of the diaphrams. That will only clean the orifices where the gas actually flows, and then down the throat of the carb. If the synch is off on Carb #1, that will affect slider action at idle, as the butterfly could possibly be open too far to allow a sufficient vacuum for slider action, or in the opposite case, closed too far, developing too much vacuum and possibly causing the one slider to actuate more than the others, hence his description of "one slider moving more than the others".

Nateo: if you could possibly hook-up your manometer again, tell us if the vacuum on #1 (left rear) registers higher than #2 (left front). Even with some blocked or partially blocked passages, a synch that is close is better than one that is off. And please let us know which slider is moving more than the others (ie: Carb #1,2,3 or 4)

 

Also, take off the air box and diaphragm covers and remove the diaphragms (watch out for the VERY small o-ring which goes into a recessed flange in the lower left of the carb body opening). Inspect these for holes (you can use liquid electrical tape as a short term fix if holes are found). Get some Berrymans spray carb cleaner and spray down the hole in the top of the carb where the little brass screw (Pilot Air Jet #1) is located. You should have a clear stream blowing out of the small hole at the bottom left of the diaphragm opening (don't look in there while you're doing it!). Do this to all 4 carbs.

 

See if this helps.

 

Dan

[GaryZ]

Seafoam will not access the port that pulls the vacuum to the rear of the diaphrams. That will only clean the orifices where the gas actually flows, and then down the throat of the carb. If the synch is off on Carb #1, that will affect slider action at idle, as the butterfly could possibly be open too far to allow a sufficient vacuum for slider action, or in the opposite case, closed too far, developing too much vacuum and possibly causing the one slider to actuate more than the others, hence his description of "one slider moving more than the others".

Nateo: if you could possibly hook-up your manometer again, tell us if the vacuum on #1 (left rear) registers higher than #2 (left front). Even with some blocked or partially blocked passages, a synch that is close is better than one that is off. And please let us know which slider is moving more than the others (ie: Carb #1,2,3 or 4)

 

Also, take off the air box and diaphragm covers and remove the diaphragms (watch out for the VERY small o-ring which goes into a recessed flange in the lower left of the carb body opening). Inspect these for holes (you can use liquid electrical tape as a short term fix if holes are found). Get some Berrymans spray carb cleaner and spray down the hole in the top of the carb where the little brass screw (Pilot Air Jet #1) is located. You should have a clear stream blowing out of the small hole at the bottom left of the diaphragm opening (don't look in there while you're doing it!). Do this to all 4 carbs.

 

See if this helps.

 

Dan

 

 

Good stuff Dan!

I need to check the little o-ring after repairing one diaphragm . . .