1990 model BMW K1 with 105,000 km. The following problem only appears in warm weather, around 23 degrees celsius or above. Below this temperature the bike operates normally. Bikes starts and operates normally for about 25 minutes then begins to develop a small stutter and continues to get worse until the engine stops. Problem does not appear to be related to the engine temperature. Hall sensors have been replaced with no change in symptoms. Note only the sensors were replaced, wiring harness and sensor mounts all original. I have a scope trace of the trigger wires from the hall sensors, one sensor appears normal but the other has a second pulse of about half amplitude at 180 degrees from the primary pulse (I have a picture I can send that's a lot clearer than my explanation). I've heated the motronic unit, coils and ignition unit with a heat gun with no conclusive results. Any help much appreciated.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
The Virago uses 20W-50 oil in warm weather. If you ask any bike shop they will recommend moving to a 10W-40 in cold weather down to about 30ish F, and if you plan on riding down to extreme temps of about 20F and below, then a 5W-30 or 5W-40 is recommended. For the 5-7C temps you list, you could really just use the same oil you use for summer. Just take a little extra time in letting the bike warm up and don't ride it hard the first couple of miles to let the oil come up to full temp. If you prefer to err on the side of caution, then use the 10W-40 oil. I had a Yamaha 650 Classic and I used 20W-50 year round and never had issues as long as I made sure to warm it up properly first.
Your Serow should get around 70 Miles per gallon (28 kilometers per liter). I find that the oil in my bike is thrashed after 1000 miles of riding. It only takes one quart of oil to change it so that is probably the best interval for a single cylinder dirt bike. In you case every 1600 to 2000 kilometers. You should use only a JASO MA certified motorcycle oil. 10w-40 for cold climate/year round. 20w-50 for warm climate/touring. Car oils use different additives and may cause scoring in certain types of cam bearings. Do not use any oil that says " Energy Conserving " on the label . It will shorten the life of your wet clutch and transmission gears. If you choose Synthetic oils, they will help your bike run cooler and shift easier. Shell Rotella T and Rotella T Synthetic 15w-40 are inexpensive JASO MA oils. Trials bikes use tire pressures around 10 PSI (.7 kg/cm). Lower pressures are used for better traction off road. Street bike tires run higher pressures around 30 to 35 PSI (2.1 kg/cm to 2.4 kg/cm)for road driving. This gives better cornering and tire wear. For good all around performance for on/off riding you probably want to run 25 to 30 PSI (1.8 kg/cm to 2.4 kg/cm). For mostly street use 30 to 35 PSI (2.1 kg/cm to 2.4 kg/cm). There is probably a sticker on the frame near the side cover that tells you the factory recommended tire pressure for your model. Ride and make adjustments from there.
Id start at replace spark plugs.. too this bike may have sensors that tell an ECM info one of these may be out of spec after a set time or temp .. id get a manual & check the locations of them. In manual the often have a trouble shooting guide..
I had one and they do get warm,but not hot.I went to a ST2.Main reason is the cost of servicing the 4s is way over the top.Maintainence is a big issue with them.Same with the Monster models.There is not a lot of difference in performance unless you really want to wring its neck around a track.They are both great to ride on the road.Hope this helps
You will open those things up, and they will probably look pretty clean, but the problem with your carbs is in the Idle circuit - too small for you to see into.
If you do a search of carb cleaning or related topics, you'll see that alot of folks with cab problems try to clean their carbs ... only to have to open them up again due to improper cleaning (They are difficult to clean properly, require alot of patience) So, I would suggest that you have them cleaned professionally, or at least buy good carb dip to get them really clean. Spray cans of carb cleaner are worthless. Might as well wash em with dish soap.
Check your kick stand sensor if it's unplugged then there is your problem.
If it's still plugged in then the sensor might be gone.
The sensor shuts the bike down if you try to take off when the kick stand is down.
you can bypass the sensor by jumping the two wires before the sensor with a piece of wire connecting the two leads together.
doing so will allow the bike to be put into gear with the kick stand down so always check it so you won't have an accident.