by Elden Carl
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Welcome to Technical Insights!
DR650 Potential Problems and Fixes
In the first half of 2005 I purchased two new motorcycles from House of Motorcycles in San
Diego; a KLR650 and a DR650.
The KLR650 stopped running at 11,000 miles due to faulty valve seals. Since I was under
warranty I had “Vey” de La Cruz clean up the top end and install quality valve seals. Now
at 15,500 miles, I have had no more problems.
The DR650 had a leaking valve cover on the left side at 15,000 miles which was easily
fixed from the outside by cleaning the surface with contact cleaner (wear gloves and work
in an open area) followed by a 3mm to 4mm wide bead of 1207B Suzuki Sealant covering
the joint between the head and valve cover. Voila, no more leak.
I have carefully tracked oil consumption on both motorcycles by using a protractor on the
rear disc and a 5 degree left lean angle. Oil consumption of the KLR650 at 15,500 total
miles is slightly better than 6,000 miles per liter, while the DR650 at 21,000 total miles on
the meter is traveling an astounding 16,500 miles on a liter of the slippery stuff.
Bruce Redding tipped me off to the only known potential DR650 problem that can blow
your engine. He had heard of several high mileage DR engines that had blown due to one
of the neutral sending unit (NSU) screws coming loose and creating terminal havoc inside
the engine. The problem seems to be that the NSU (which is located inside the engine to
the rear and behind the clutch basket) is made of plastic-like material which collapses
under the fastener from heating and cooling over time. Since the screws aren’t loctited
and can’t tighten themselves to take up the slack, they loosen and eventually come out of
My 2002 NSU screws were checked at 25,000 miles. One had loosened about 3 turns and
the other still had contact but was less than finger tight (thanks for saving my engine
The fix is simple:
*The normal fasteners are 5mm x 16mm screws (.8 pitch). I replaced mine with 5mm x
20mm hex head bolts to engage a few more threads.
I replaced these fasteners at 7600 miles. I was surprised to find that although still in
contact, the fasteners were only finger tight.
Although I don’t think I’ll have to worry about my fasteners, I plan to check them around the
20,000 mile mark. I’ll certainly keep you posted.
- Remove the clutch cover (remember to drain oil first!)
- Remove the clutch basket assembly
- Remove the breather plate
- Remove the two NSU fasteners and move NSU aside
- Using upgraded fastener*, liberally apply low-strength loctite and thread in fully
- Put NSU in place, re-apply loctite, and tighten down with upgraded fasteners* and
5mm serrated lock washers
- Replace the breather plate using upgraded flange fasteners properly torqued
- Replace the clutch assembly after measuring your plates for possible
- Re-install engine oil and go riding
Since I never use a neutral light the removal of the NSU was a no-brainer for me, but Todd
Vosper likes his as do many other riders. Skipper, would you take over from here and tell
the folks what you did to your NSU?
Elden’s solution may not be elegant, but it certainly allows him to sleep at night knowing
those NSU screws are never going to be a problem. Being one of those young whipper-
snappers that rely on new technology (like neutral lights… just kidding Elden) I wanted to
try a different solution. I really don’t have a love-affair with my neutral light, but it seemed
to me that there should be a way to solve it without losing the light.
I essentially followed the same sequence as Elden until step D:
A. Remove the clutch cover
B. Remove the clutch basket assembly
C. Remove the breather plate
D. Remove the two NSU fasteners and the NSU, including the plunger and spring (plug
crankcase holes with lint-free rags so you don’t drop parts into the engine)
E. Replace the breather plate using upgraded flange fasteners properly torqued and
F. Properly reassemble all clutch parts, replace clutch cover, etc. (Note: Don’t forget
to measure your clutch plates)
G. Re-install engine oil and go riding