Jump to content

2008 WR250F e-staring issue with 450's intake?? whaaaaat!!

Recommended Posts

Hello, well i recently bought an old 2008's Wr250f. The thing was, the engine was torn apart. So i started assambling it up, and came up with the complete engine. I was missing some small parts, that luckily i could use from a dead wr i used to have.

Longstory short, when i was setting up the timing, i found no way to make it face the right timing, but i did it somehow and it worked, sort of.

See, the problem is with a brand new, fully charged battery i attemp to e-start the bike and the engine seems to get stuck at one point of the cycle. But if i help it with the kickstarter at the same time it starts right away and has no problem running the engine once is warmed up. I took it to some yamaha dealer here, and the mechanic said the problem was that i had been running the engine with a wr450 intake camshaft!!! ((O_o)) I dont know if that's even possible, but sounds about right, since cam lobes are different set, and auto-decompressor is at another angle.

I've been trying to find a good wr intake camshfat but i would like a second opinion on this before i buy, since the mechanic checked the bike very lightly i still have my doubts about it. Is there a way to know for sure if im running a 450's camshaft?? 

Edited by nico3dd

Share this post


Link to post
Share on other sites

I would think the issue would be with the exaust cam, not the intake. The exaust cam has the auto decompression lobe. I believe that if you do the "yz" cam mod to a wr the auto decompression no longer works properly. This consists of retarding the exhaust cam 1 tooth. I've read that you can kick start but the e start does what your is doing.

Sent from my SM-G900T using ThumperTalk mobile app

  • Like 2

Share this post


Link to post
Share on other sites
5 hours ago, DarrellH3 said:

I would think the issue would be with the exaust cam, not the intake. The exaust cam has the auto decompression lobe. I believe that if you do the "yz" cam mod to a wr the auto decompression no longer works properly. This consists of retarding the exhaust cam 1 tooth. I've read that you can kick start but the e start does what your is doing.

Sent from my SM-G900T using ThumperTalk mobile app
 

All right then. I was thinking the same thing. Ill trying to change it and update the results. 

Share this post


Link to post
Share on other sites

Hello guys! after a while struggling with the problem, I finally received the cams! after installation, the problem is still the same, nothing changed.  :(

I was told it could be the starter clutch that was having some issues, but after checking it, was OK, no big wear or anything weird on it.

   Then reading a little more,  came to the conclusion it was the torque limiter or "starter damper gear"... have you guys ever dismantle one of this? I have no idea what I'm going to find inside. I111.jpg.f1f62dde55aed2ab13959c32d53d9778.jpgts the number 3 in the image.

Share this post


Link to post
Share on other sites
On 8/29/2017 at 7:50 PM, DarrellH3 said:

Sounds like the exact symptoms as the yz timing mod. Might try advancing exhaust cam by 1 tooth.

Sent from my SM-G900T using ThumperTalk mobile app
 

im sorry i left to die this post. Was working abroad. just came back and tried that first. but still nothing. This is what it sounds like : (the first 10 seconds)

its like its too much compression to the e-starter motor...

Share this post


Link to post
Share on other sites

Double check to make sure the timing chain is good and fresh... no tight spots or chunky kinky feeling in chain...

also with the timing chain off spin both cams separately and make sure they spin easily with caps torqued down...

also check your cam chain tensioner and make sure it’s keeping proper tension on the chain...

 

 

Share this post


Link to post
Share on other sites
On 1/19/2018 at 11:43 AM, Yakattack said:

Double check to make sure the timing chain is good and fresh... no tight spots or chunky kinky feeling in chain...

also with the timing chain off spin both cams separately and make sure they spin easily with caps torqued down...

also check your cam chain tensioner and make sure it’s keeping proper tension on the chain...

 

 

I double checked all three points. But still about the timing settings i have some doubts, because at the flywheel magneto I can see 3 vertical lines, one has an H the other an F and those 2 are united by a curved horizontal line( it looks something like this |______________|  ). and closer to that one i could find a third vertical line, so I'm not really sure wich one of those three is the correct one.

Other thing I've tried is moving back and forth a tooth the exhaust cam (wich is the one that has the automatic decompressor), without better results.

 

1 hour ago, ronbuell said:

How old is your battery?

its new enough. And I'm pretty sure its not a battery issue since the same battery could e-start my KTM without hesitation. Also I've tried hooking my CBR's (bigger) battery on the WR and same result.

Share this post


Link to post
Share on other sites
9 minutes ago, ronbuell said:

Then I'd say there's a dead loop of wire on the starter commutator.  You could get it re-wound or get a new starter.

 

I don't think is that either. I just checked the voltage at the battery and its 14.1V, when bike is on. Also I tried hooking up the cables directly from an outside battery to the e-starter motor and same symptom.

Share this post


Link to post
Share on other sites

Voltage on the battery has nothing to do with wiring on the commutator in the starter.  Hooking a battery directly to the starter will not test your commutator.  

The test is to remove the commutator from the starter, the starter shaft, use an volt/ohm meter, and measure resistance between each contact strip on the commutator.  When you find one that is out of spec or shows open circuit, that's confirmation of the problem.  If all check out, then check other causes.  On a starter, it will be either the commutator or brushes.  When I pull one out to replace brushes, I will use emory cloth to clean the commutator strips by turning it by hand, and a pointy pick to clean between eat strip, and spray off with brake cleaner to remove carbon and filings.  Good luck, hope you find the issue.

Share this post


Link to post
Share on other sites
32 minutes ago, ronbuell said:

Voltage on the battery has nothing to do with wiring on the commutator in the starter.  Hooking a battery directly to the starter will not test your commutator.  

The test is to remove the commutator from the starter, the starter shaft, use an volt/ohm meter, and measure resistance between each contact strip on the commutator.  When you find one that is out of spec or shows open circuit, that's confirmation of the problem.  If all check out, then check other causes.  On a starter, it will be either the commutator or brushes.  When I pull one out to replace brushes, I will use emory cloth to clean the commutator strips by turning it by hand, and a pointy pick to clean between eat strip, and spray off with brake cleaner to remove carbon and filings.  Good luck, hope you find the issue.

what would the range of spec be?

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:


×