Question about S Dual Fire Ignition System-Motorcycle

1 Answer

I have an uncontrollable high idle problem on only one side of my 1978 BMW R100/7. Everything checks out. No air leaks, new plugs, rebuilt carbs, adjusted valves, good compression. The only thing left is the electronics. Could a bad electronic ignition system cause high idle on one side?

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 5,678 Answers

Do you have like TPS sensor or IAC sensor.

Posted on May 09, 2013

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Why 2-Cycle engine poulan chainsaw will not idle


It sounds like you have an air leak from carb to carb adapter.

Jul 24, 2014 | Poulan 2050 2055 2975 2150 2155 2175 Air...

1 Answer

Help husqvarna 372 chainsaw will not run


check with a husq.dealer,they had some crummy carbs that may need replaced not rebuilt

Mar 06, 2014 | Husqvarna Garden

1 Answer

I can't get my saw to idle down,i have adjusted my jets and nothing i'm doing is helping.Do you think i have an air leak.Idon't really know to remove the carburetor. thank you


Classic air leak problems causes high uncontrolable idle, before anything else push the throttle spindle hard onto its stop just in case it is the spindle not returning properly, check the throttle flap in the carb has not come lose and is binding in the carb body.

Feb 18, 2011 | Husqvarna ChainSaw 18 in Bar 32 HP Model...

1 Answer

Had carbs rebuilt on my 1975 Yamaha Xs 650 now the left side cylnder fires infrequently and backfires loudly with new plugs. could this be a timing issue?


If it's just one cyl, then I doubt its timing.
Check to make sure the carb boof is tight and not leaking
also check any vacuum hoses.

Oct 12, 2010 | 1978 Yamaha XS 650 E

1 Answer

Idles very high


It could be sucking air from the right side crankshaft seal, where the generator is. Or it could have an air leak at the crankcase center gasket, or carburetor intake manifold. I have found that spraying WD-40 around the suspected areas (with the engine running) helps to locate air leaks because the idle speed will change noticeably when the WD-40 hits it.
Also check that the carburetor slide isn't hanging up inside the carburetor and that your throttle cable is routed correctly and has at least some free-play at the twist grip.

Nov 22, 2009 | 2006 KTM 525 SX

1 Answer

I have a 1978 R80/7 BMW motorcycle with Bing diaphram carbs that have been rebuilt with new parts. It will start and run but only if I almost completely cover the carb inlets. I will not run with the choke...


it could be that you have a vacuum leak between the cylinder and the carb that is leaning out your fuel, check the connection between the the two. to confirm that there is a vacuum leak spray some brake cleaner or any flammable gas on the connection between the two and if the revs go up, you found the problem... hope that helps

Aug 13, 2009 | BMW R 80 Motorcycles

2 Answers

1978 Suzuki GS 1000 revs up on its own.


Hi and welcome to FixYa,

To my understanding, an air leak would be anywhere before the carbs; the air box  cover, the the 4 coupling rubber tubes or even the air filter itself.  Although an air leak in any of these areas would not cause an intermittent high idle. Air leak here would cause a lean mix and/or a flat spot while accelerating.  

On the other hand, a vacuum leak could cause high idle. Vacuum leak would be after the carbs and on any of the coupling to the intake ports of the engine or how they are fitted. In some versions, there are balancer nipples that have interconnecting rubber hoses and/or a vacuum line to the fuel cut-off valve that couls also have a hole or tear. It must be noted that the high idle because of a vacuum leak is consistent.

Intermittent high idle would often be mechanical or almost always on the throttle system. Common causes are:
  • corroded, dirty, unlubricated, throttle mechanism or cable or linkages;
  • pinched, kinked or sharp bended cable housing;
  • forced or irregular routing of the cable;
  • it must also be pointed that sticking sliders (inside the carbs) can cause irregular (high) idle.
Good luck and thank you for asking FixYa.

Aug 06, 2009 | 1978 Suzuki GS 750 E

2 Answers

High idle on start up with choke off.


This sounds like an air leak is making the fuel/air mixture too lean. Any air leaks between the carb and the head will lean the mixture. Old, hard and cracked rubber manifold parts are the usual culprits. Old gaskets and "O" ring seals can leak air also. A bad head gasket seal happens at times also, as does an exhaust valve not fully seating. Air leaks are the idle speed problem.

A different problem is likely present in the carbs and that is what is causing the rich fuel smell. The carbs must be balanced. Example > If three of four carbs are perfectly balanced and one carb is not, then the 3 are "driving" the 4th carb. This will cause gas to spit into the air cleaner from the "bad" carb and can cause a backfire or two. Special vacuum gauges are needed to balance the carbs. Also be aware the carbs must be scycronizsed as well. The slides on all four carbs must lift at exactly the same time when the throttle is cracked.

Go to the site below where you can see a parts diagram for your specific bike. You will select the actual brand, year, model, etc., once you go to the site. Part numbers and prices are also shown. You can order parts from this site. In the event no price is shown on a particular part, the part is not in stock. www.babbittsonline.com/pages/parts/viewbybrandand/parts.aspx

I don't get paid for my answers but I do take pride in them, and I am only trying to help. So if you will, > > A “very helpful” rating for these answers? Thanks!

Jun 14, 2009 | 1977 Suzuki GS 750

Not finding what you are looking for?
S Dual Fire Ignition System-Motorcycle Logo

62 people viewed this question

Ask a Question

Usually answered in minutes!

Top Dynatek Vehicle Parts & Accessories Experts

yadayada
yadayada

Level 3 Expert

76691 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

14382 Answers

Brad Brown

Level 3 Expert

16043 Answers

Are you a Dynatek Vehicle Part and Accessory Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...