GT750 Posted July 16, 2006 Share Posted July 16, 2006 Hello, I am new to BMW and this board... My name is Allen and I live in Panama City Fl.. I have been doing Iron Butt rides on a 74 Suzuki GT750 two stroke and my wife finally talked me into getting a Beemer...She was tired of smelling like injector oil when we arrived somewhere... I recently picked up a 1996 R1100RT with 58K miles.. The bike has run great...But today it started to rain buckets..First time wet since I got it.. Within about one minute of that, the bike stumbled and shut down.. I coasted to the side and it would not restart... I had to get a ride home and get a trailer to bring it back... Since it has dried some it has restarted, but only for a few seconds and then shuts off again...The battery is new and has a full charge and I can hear the fuel pump cycle on when the key is switched on.. Does this sound familar to anyone?? Any help will be greatly appreciated.. Thanks again, and glad to be here.. Allen...Rideaholic IBA21871 Link to comment
smiller Posted July 16, 2006 Share Posted July 16, 2006 The age of your bike and symptoms of the failure point to an extremely high probability of a bad HES (Hall Effect Sensor) harness. It's common for the HES wiring harness insulation to fail over time due to being exposed to a very high level of heat, and when it does the symptoms are exactly as you describe. There are several ways to go at the repair, you can simply replace the entire HES assembly but the part is around $200 and probably all that has failed is the insulation. If you are mechanically handy you can replace just the wiring harness alone with some teflon or other high-temp wire insulation at low cost and you will most likely end up with a 100% repair, or even better than that since you will have ensured that you won't have a repeat failure. There is a guide that explains the whole process, I'll find it and post it here shortly if no one beats me to it. Link to comment
David Posted July 16, 2006 Share Posted July 16, 2006 Allen, it may well be the HES--hall effect sensor. A common sign on older bikes (that might have gotten hot at some point) is that they exhibit this behavior. You might be able to test that theory by pulling the alternator cover, turning it on, and spraying a water bottle on the sensor (toward the top, I believe). Link to comment
David Posted July 16, 2006 Share Posted July 16, 2006 Looks like Seth types faster than I do. Link to comment
matanuska Posted July 16, 2006 Share Posted July 16, 2006 Allen, Welcome Sorry to hear of your misfortune. ...Does this sound familar to anyone?? Sadly, yes. Start with this: http://advwisdom.hogranch.com/Wisdom/oilhead_hall_sensors.pdf Then with this. And keep searching, you'll find more than you ever wanted to know! Cheers DR Link to comment
matanuska Posted July 16, 2006 Share Posted July 16, 2006 Looks like Seth types faster than I do. Damnit, you're both faster than me! I'm a hunt-and-peck typist! Link to comment
skinny_tom (aka boney) Posted July 16, 2006 Share Posted July 16, 2006 It never occured to me before to post this, but if you're in search of 105 degree Celcius automotive grade wire, HERE is a good, inexpensive source for automotive grade high temp wire in multiple colors. The catch is that you have to buy 20 feet of each color, but that still comes to less than $3/color. No afilliation. Just a satisfied customer. Link to comment
GT750 Posted July 17, 2006 Author Share Posted July 17, 2006 Thank you all, for your help.. When I get it back running I will let you know what it was.... It does sound like the HES is the problem, from the symptoms I am having.... At least it was only 15 miles from home and not on my Iron butt 50cc ride... I will put in away for now, and I'm getting ready to ride up to Mid Ohio for Vintage days in about 2 weeks... But I would be riding the old Water Buffalo on that adveventure... The bad part is this Beemer has spoiled me.. It is the best bike I have ever had.. Thanks again... Allen........Rideaholic Link to comment
duckbubbles Posted July 17, 2006 Share Posted July 17, 2006 Hi, Allen- It appears that everybody has jumped on the Hall Effect Sensor bandwagon but I have another suggestion. It could very well be the coil. Many times the HES goes bad and the bike quits running and after it cools off, sometimes 10-15 minutes, it will start and run for a while again. My cousin has a '97 RT and has had this happen twice after riding through rain. Last weekend I spent time on the phone with a friend who is riding through Alaska and had the same thing happen to him. Also check all the connections that have anything to do with the ignition. It may be possible that the sidestand switch is to blame. Hope you get it fixed soon. Frank Link to comment
GT750 Posted July 17, 2006 Author Share Posted July 17, 2006 I just went out to the garage again and the bike fired up and ran perfect for about 30 seconds, I then put the kickstand down and it shut off as it should.. I restarted it, and it ran for about another 15 seconds then just quit.. I tried to restart it again, but it would only spin over and try to start and then would backfire a little... So I dunno.. Allen Link to comment
matanuska Posted July 17, 2006 Share Posted July 17, 2006 ...It appears that everybody has jumped on the Hall Effect Sensor bandwagon but I have another suggestion. It could very well be the coil. ... The article also contains instructions on checking the coil. Yes, you could get sidetracked going down the HES route when the coil may be the problem so follow the directions as the coil checks take all of about ten minutes. DR Link to comment
duckbubbles Posted July 17, 2006 Share Posted July 17, 2006 The experiences of the people who I know that have had the coil fail was when it failed, that was it. No more runny at all! I guess I am jumping on the HES bandwagon now. Frank Link to comment
flars Posted July 17, 2006 Share Posted July 17, 2006 The quickest test would be to bypass the side stand switch. They are definitely known to fail WHEN WET, and they sometimes don't behave normally after that because they don't seem to want to dry out by themselves. Shoot it with something to drive any residual water out, let it dry, and try it again. If that doesn't work, then jumper the wires. If this is the problem, then the total cost of the test is zilch, and it you can leave it jumpered until you can replace it. The HES is a real possibility, but check the side stand switch first. Link to comment
GT750 Posted July 18, 2006 Author Share Posted July 18, 2006 I know with the side stand switch, the motor would not even turn over until it was swung up.. When the bike stalled, it would spin over, just not start... Last night after sitting awhile it would restart for a short time and quit again... I let it sit over night with a fan blowing at the front of the motor.. This morning I went out and it fired right up and ran perfect.. I let it run awhile, but did not ride it.. It looked like rain again.. I decided to pull it apart and ordered a new HES.. The previous owner told me that it was the original one, so I figured it would be a good investment... He talked me through the disassembly and has been very helpful.. Now lets see when it gets here if I can make it run again... Thanks again to everyone who helped me.... Allen.......Rideaholic Link to comment
bmwmick Posted July 19, 2006 Share Posted July 19, 2006 I know with the side stand switch, the motor would not even turn over until it was swung up.. When the bike stalled, it would spin over, just not start... Last night after sitting awhile it would restart for a short time and quit again... I let it sit over night with a fan blowing at the front of the motor.. This morning I went out and it fired right up and ran perfect.. I let it run awhile, but did not ride it.. It looked like rain again.. I decided to pull it apart and ordered a new HES.. The previous owner told me that it was the original one, so I figured it would be a good investment... He talked me through the disassembly and has been very helpful.. Now lets see when it gets here if I can make it run again... Thanks again to everyone who helped me.... Allen.......Rideaholic Allen, I sent you a PM. Let us know if you have trouble timing it, it's pretty basic. Mick Tucson Link to comment
GT750 Posted July 21, 2006 Author Share Posted July 21, 2006 Well it is running again.... I put the new HES on it and screwed it all back together.. As far as the timimg went, what I did was scribe marks on the old HES and the motor.. I then made the same ones on the new part and reinstalled it in the same position... The bike fired right up.... I then rolled it out to the driveway and put it on the Centerstand.. Let it warm up a little and then turned on the water hose to imitate a down pour at the front of the bike... I did this for about ten minutes and it stayed running... So, its no longer afraid of water .... Mick, I will be sending you my old one to get a rebuilt one for a spare, or maybe help another person if needed on the road one day.. Again, I would like to thank everyone for there help in this quick fix.... Now I am getting ready to head up to Mid-Ohio for vintage days.... But I will be riding my GT750 smoker to that.. So if anyone sees a black Suzuki two stroke with a fuel cell on the back, just wave, or throw a rock.. Allen.......Rideaholic Link to comment
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