R1100RT cut out in wet and wont restart

[daveyboy27uk]

Last week my RT let me down for the first time in ages. I was cruising down the motorway in a torrential storm at a fair pace when the engine just died on me. I managed to get it to the side of the road and gave it ten minutes, it started again but then did exactly the same thing moments later. I ended up having to have the bike recovered the 400 miles home. I went out this morning and jump started her and she started first time, left her running for a few minutes on idle and she just cut out and now wont start again. The weathers been good for the last few days and I would have thought she'd have dried out. I have sprayed everything I can get to with WD40 but she still wont start. The plastic spark plug covers do their job and there is no moisture around the plug or plug leads. Anybody have any idea what the problem is or experienced a similar fate. I have used the RT in much worse storms than this and never had a problem. I need my RT on the road as soon as possible so please help!!!

[Joe Frickin' Friday]

Last week my RT let me down for the first time in ages. I was cruising down the motorway in a torrential storm at a fair pace when the engine just died on me. I managed to get it to the side of the road and gave it ten minutes, it started again but then did exactly the same thing moments later. I ended up having to have the bike recovered the 400 miles home. I went out this morning and jump started her and she started first time, left her running for a few minutes on idle and she just cut out and now wont start again. The weathers been good for the last few days and I would have thought she'd have dried out. I have sprayed everything I can get to with WD40 but she still wont start. The plastic spark plug covers do their job and there is no moisture around the plug or plug leads. Anybody have any idea what the problem is or experienced a similar fate. I have used the RT in much worse storms than this and never had a problem. I need my RT on the road as soon as possible so please help!!!

 

Hall Effect Sensor (HES) on the front of the crankshaft; the Motronic uses this to keep track of crankshaft position for injector/spark plug timing. After some years in service, the insulation on the HES harness hardens and cracks with heat, and then moisture gets in during a bad rainstorm and grounds out the signal. This is, unfortunately a very common failure, and your symptoms line up very well.

 

Unfortunately it's not a cheap part; here in the states it's around US$250 for a new one. You can verify the problem here; they also show how to repair it, but if you're in a hurry to get your bike running, my advice is to just buy a new one, and then (at your leisure) repair the old one and carry it as a spare.

[Boffin]

This sounds like the HES harness failure. On the front of the engine, behind the alternator cover, is a plate holding two Hall Effect Sensors. The loom to this is clamped to the front of the engine and in time deteriotes due to the heat. This leads to cracking of the insulation so the bike fails in wet weather. It is fairly straightforward to replace the HES assembly Motobins or James Sherlock may have a used replacement. Better still would be to remove the damaged wireing and replace with high-temperature wire. In the majority of cases the HES' are still serviceable.

 

Do a search on HES on this site for more info. One of the US members ( bmwmick) makes replacement harneses, I do not know if he ships them overseas.

 

Andy

[daveyboy27uk]

Thanks i'll give it a try and see what happens. I don't mind spending money and getting a new one if it's going to cure the problem.

 

Cheers

Dave

[T__]

Last week my RT let me down for the first time in ages. I was cruising down the motorway in a torrential storm at a fair pace when the engine just died on me. I managed to get it to the side of the road and gave it ten minutes, it started again but then did exactly the same thing moments later. I ended up having to have the bike recovered the 400 miles home. I went out this morning and jump started her and she started first time, left her running for a few minutes on idle and she just cut out and now wont start again. The weathers been good for the last few days and I would have thought she'd have dried out. I have sprayed everything I can get to with WD40 but she still wont start. The plastic spark plug covers do their job and there is no moisture around the plug or plug leads. Anybody have any idea what the problem is or experienced a similar fate. I have used the RT in much worse storms than this and never had a problem. I need my RT on the road as soon as possible so please help!!!

 

 

Dave, as mentioned could be the hall sensor.. Or any number of other possible problems.. About all you can do is work your way through them__ test for good spark,, test for good fuel to the injectors,, look for good injector spray while cranking, etc..

 

If you have an aftermarket fuel controller on that bike (like the Techlusion) I will almost bet the farm that is your problem.. The early units had poor circuit board waterproofing & could fail when wet.. If that is your problem you (usually) can’t just simply turn it off but need to completely remove it’s wire hook ups..

 

 

Twisty

[Charles Elms]

Also carefully check your coil for small cracks in the plastic that will let moisture in.

[Boffin]

Thanks i'll give it a try and see what happens. I don't mind spending money and getting a new one if it's going to cure the problem.

 

Cheers

Dave

 

A new HES from James Sherlock is £141, Motobins show the earlier type at £95 and the later (1150) at £138.

 

Andy

[daveyboy27uk]

I'm a real novice when it comes to Boxer mechanics, is the HES sensore easy enough to change?

 

Cheers

[bmwmick]

I'm a real novice when it comes to Boxer mechanics, is the HES sensore easy enough to change?

 

Cheers

 

Davey,

You should have no problems changing it. Just note carefully how the existing one is adjusted in relation to the slots in the HES plate. Put the new one in the same place and it will run great till you can verify the timing using the above referenced site.

 

Mick