Jump to content
Sign in to follow this  

06 DRZ400SM After Engine Rebuild only turns CCW

Recommended Posts

Hello all...new to me DRZ400SM, I bought it with known engine damage that turned out to be the big end con rod bearing let go and spit debris everywhere. It would start and run, but smoked, and knocked of course.

I've replaced the crankshaft assembly, the piston and cylinder. It's all back together, with no issues except: the engine will only rotate counter-clockwise (as viewed from the left side, turning from the left side crank nut with inspection cover removed). Hitting the e-start button only results in a heavy click of the solenoid, no engine rotation at all, even by hand...it's completely locked only in a clockwise direction. I popped the starter out and it spins freely with the start button depressed, and I verified the starter clutch is installed properly, with washers in their proper spots.

I found a thread on TT where a guy had this similar problem after doing the loctite process as recommended on this site (which I also did). His fix was aligning the counterbalancer & crank sprockets on the right side, dot-to-dot and to a mark on the case. I definitely set the dot-to-dot part with the crank at TDC, dots were definitely aligned. I didn't align anything to the case mark as he mentioned, however prior to disassembly I noted with the crank at TDC the dots were aligned, so I followed the same process on reassembly. I'm not convinced this is my problem. It's locked so tight CW, like the sprag for the starter gear is acting on the flywheel also.

Looking for a little help, any thoughts would be greatly appreciated!!

Share this post


Link to post
Share on other sites

If it spins free in one direction and locked in the other, it almost has to be in the starter gear train someplace. Even if the sprag clutch were backwards the motor will rotate the starter backwards. I would start by pulling the left cover and see what is going on in there. Once you remove the idler gear that drives the flywheel you will hopefully be able to rotate the motor in both directions. If not, you will be a lot closer to the answer.

  • Like 1

Share this post


Link to post
Share on other sites

If it spins free in one direction and locked in the other, it almost has to be in the starter gear train someplace. Even if the sprag clutch were backwards the motor will rotate the starter backwards. I would start by pulling the left cover and see what is going on in there. Once you remove the idler gear that drives the flywheel you will hopefully be able to rotate the motor in both directions. If not, you will be a lot closer to the answer.

You're right, and that's what I did. And the problem was found, so this is a "learn from my mistake" topic. Do not assemble the starter idler pinion this way:

IMAG1047_zps63459322.jpg

The large washer is intended for the starter clutch shaft, and was smushed between the idler pinion and the cover. Soon as I undid the cover the engine would rotate either way. Assemble it this way, THE RIGHT WAY, and everything works as it should. Shop manual and the parts fiche doesn't lie. Engine starts and runs great!

IMAG1048_zps5a377e71.jpg

  • Like 2

Share this post


Link to post
Share on other sites

If it spins free in one direction and locked in the other, it almost has to be in the starter gear train someplace. Even if the sprag clutch were backwards the motor will rotate the starter backwards. I would start by pulling the left cover and see what is going on in there. Once you remove the idler gear that drives the flywheel you will hopefully be able to rotate the motor in both directions. If not, you will be a lot closer to the answer.

:worthy:

Share this post


Link to post
Share on other sites

The Idler gear you show uses 2 identical thrust washers, 1 on each side of the snap ring. Shop manual and parts fiche do lie. If you assembled it as shown in the second picture it is wrong but probably not worth changing. Well documented here on TT.

By the way, all the idler gears I have seen have a waist in the middle so it looks like 2 gears. Hmm interesting

  • Like 1

Share this post


Link to post
Share on other sites

The Idler gear you show uses 2 identical thrust washers, 1 on each side of the snap ring. Shop manual and parts fiche do lie. If you assembled it as shown in the second picture it is wrong but probably not worth changing. Well documented here on TT.

By the way, all the idler gears I have seen have a waist in the middle so it looks like 2 gears. Hmm interesting

The 2nd picture and the angle of the photo make the washers appear different, but they were identical. I see what you're saying, it's easy enough to remove the left cover and put the washers in the locations you mention, either side of the snap ring. Is there a different year shop ,manual that shows the washers installed the way you mention, or is that a "tribal knowledge" thing from experience on engine tear downs?

Edited by apexing

Share this post


Link to post
Share on other sites

Yes, I see the 2 washers are identical. The point I intended to make is the assembly order is - washer, snap ring, washer, gear.

Share this post


Link to post
Share on other sites

No, the manuals all show it the WRONG way...why never corrected? no idea. As for "tribal" knowledge... ehhh it is what it is... You can find it published in several tech articles here on this forum, and quoted about a million times across the internet,, since back at least to 2003.

I see in your photo you took apart the starter torque limiter ...how are you planning on putting that back together? You do know you have to compress the stack and NOT just presses from one side against the snap ring on the other... Yes?

.

The 2nd picture and the angle of the photo make the washers appear different, but they were identical. I see what you're saying, it's easy enough to remove the left cover and put the washers in the locations you mention, either side of the snap ring. Is there a different year shop ,manual that shows the washers installed the way you mention, or is that a "tribal knowledge" thing from experience on engine tear downs?

Share this post


Link to post
Share on other sites

No, the manuals all show it the WRONG way...why never corrected? no idea. As for "tribal" knowledge... ehhh it is what it is... You can find it published in several tech articles here on this forum, and quoted about a million times across the internet,, since back at least to 2003.

I see in your photo you took apart the starter torque limiter ...how are you planning on putting that back together? You do know you have to compress the stack and NOT just presses from one side against the snap ring on the other... Yes?

.

No, the manuals all show it the WRONG way...why never corrected? no idea. As for "tribal" knowledge... ehhh it is what it is... You can find it published in several tech articles here on this forum, and quoted about a million times across the internet,, since back at least to 2003.

I see in your photo you took apart the starter torque limiter ...how are you planning on putting that back together? You do know you have to compress the stack and NOT just presses from one side against the snap ring on the other... Yes?

.

Yes. Used a vise on one half, and a c-clamp on the other to compress the spring washer stack and get the clip on. I've put 70 miles on the bike since putting everything together and it runs perfect. I do plan on taking the gen cover off and installing the washers correctly on the pinion shaft. Thanks for all the help!

Share this post


Link to post
Share on other sites

Gonna resurrect this thread.  I pulled my stator cover off and pulled out the starter idle gear.  Mine had been originally assembled or replaced back as:  washer, snap ring, gear, washer.  I'm gonna put it back washer, snap ring, washer, gear.  I'm questioning the use of bushings.  I'm not at the garage now, but I thought I remember a bushing in the case hole that the idle gear shaft goes into.  But, also, playing around with fitment, it looks a like a washer and bushing could/would fit on shaft outside of the gear--to keep the gear off the stator cover.  And as the starter clutch gear shaft, which has washers/bushings on each end of the shaft.  Eh?

Share this post


Link to post
Share on other sites

The bushings you are thinking about are for the torque limiter shaft.  The gear train is - starter motor - torque limiter clutch - idler gear (actually for more reduction) - starter clutch (behind the flywheel).  Don't confuse the torque limiter clutch with the starter clutch.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks.  No confusion, except for being confused that one of the washers was on the outside of the idle gear.  Having been in the garage now, and seeing there is no bushing on the inside end of the idle shaft, and that putting the same size washer--as parts fiche's show--on the outside of the gear, is wrong--as those washers are larger than the shaft on the outside, and would wobble around, wearing a groove in the shaft.  I was just thinking that there should be a washer there on the outside to hold back the gear from touching and wearing on the cover.  Not sure what kind of play if any there is between the gear and the cover.  Anyway, all is good.  Did the stator bolt loctite fix while I was in there.

 

BTW, for anyone taking things apart in there, watch that washer on the inside of the idle gear when you pull that idle gear off.  Mine stuck to that crankcase cover, but dropped down behind the flywheel as I went to grab it off.  Oh shit, do I now need to pull the flywheel? I thought.  And then I see the opening down below down into the crankcase bottom / sump.  Did it drop down in there?  Oh shit.  Stuck a magnet down in that hole, and sure it enough--clink--it pulled the lost washer to it.  ;)

  • Like 1

Share this post


Link to post
Share on other sites

Well done. Yup those washers can be a rascal when they drop.  Good to keep track of them.  I have a story about dropping a stainless (non magnetic) washer into the top of a KTM motor.  Of course I was never sure of where the missing washer went.  Eventually found it but took some time.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×