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ede March 31st, 2017 03:40 AM

FE 501 2002 - Ignition Timing - Decomp - Starting Problems
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I'm from Germany and already a member for a while (2015) and reading your posts with interests.

I bought a FE 501 model 2002 a while ago. Since I own the bike there's permanent trouble with it. I had it already in a former Husaberg workshop to get the engine fixed (ball bearings, sealings, etc.), but finally I received the bike from the shop as non-runner. They couldn't get it started. Long story short, now I'm giving myself a try to get the bike alive again. Thanks in advance for any help.

When I received the bike from the workshop I could get it started using starting fluid. I took a short ride but at full throttle the engine back fired and couldn't get started again.

Problem with starting:
* starter motor cannot spin the engine over TDC
* the best one could get with the kickstarter was a single misfire, then for a while nothing

So my assumption is there is a problem with the auto decomp mechanism and with the ignition timing. I cleaned the carburettor first, to make sure there is everything o.k.
Carburettor is clean - but nothing better.

I then checked the ignition timing, which seems to me completely wrong when engine is in TDC (picture below).

zaga March 31st, 2017 06:11 AM

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You have the most common problem with earlier BERGS, that a lot of owners have, and it is vey frustrating :mad:

When you get it right, it will start very well, a lot of the times it's not a big problem, but it's a lot of small tune problems.

So the problem with e-start you can fix it with a stronger spring for the auto decomp, that Taffy will sell you. You can also update the auto decomp for a newer one. You can also update the starter with a beffy one and you can use a YTZ 7S battery :eek: Are you frustrated already ??:D

Start with the spring, that is the cheapest thing :)

About the timing, I'm sending you one doc that I've made some time ago. This is a method using a strobe light, that is the most correct, because with this CDI's you never know.
If you have any difficult let me know, and I will try to explain better.

Some times the start problem can be solved just turning the idle screw, some this the idle is just too low and the bike won't start. As a start configuration you can use a 4mm drill and measure the height of the carb slider.

Off course, you must check the values od the stator, valve clearance, etc ...

When you get it right, it will put a smile on your face :D


Taffy March 31st, 2017 11:59 PM

if the bike is at TDC in the photo and you have the two lines where they are in the have a big problem!

it is the wrong flywheel.

the correct flywheel has two lines yes but they are just before TDC. you mark a third one and tipp-ex it white.



ede April 2nd, 2017 01:22 AM

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Hi Zaga,

thanks for the good advices. The manual you made is great! The reason for the weird timing I guess is found. First I thought someone installed a different crank, or that the crank could be broken... The woodruff key on the crank got sheared off!

ede April 2nd, 2017 01:27 AM

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Hi Taffy,

thanks for your help. I also thought about the flywheel could be the wrong one - some time ago I already bought one of yours - comparison below - looks like the marks are similar to the mark on your flywheel. So the flywheel is probably o.k.

ede April 2nd, 2017 01:33 AM

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Woodruff key is:
Standard DIN 6888
KTM Part Number: #0888030050

With new woodruff key and Taffy's flywheel the timing mark looks about at the right position - just the stator seems to be at wrong position... maybe that's what caused the backfire at full throttle... and therefore the sheared woodruff key... I don't know.

Taffy April 2nd, 2017 02:12 AM

check that the magnets are in the same position inside the flywheel. look at them through the potting.


ede April 8th, 2017 04:45 PM

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Thanks Taffy, I'll do so.

I guess I got the issue with the weird timing...

About the decomp-issue:

The decomp lever shows some wear at the contact area. It also touches the bearing (pic 2) and wears out there too. Somehow the lever is fitted tight between the shoulder touching the bearing and the end in the nut of the camshaft. When pressing it slightly towards the camshaft gear/away from the bearing if moves easily. But after a few times it rests again halfway.

I bought a decomp and measured its length (pic 3) - It seems to be a little more short than the one installed - about min. 1mm, but not more than 2mm. Will the spring hold the device in place? Is there a reason why not to install the shorter decomp device?

Taffy April 9th, 2017 01:03 AM

if the camshaft centre protrudes through the sprocket by around 0.2mm you are OK to fit the later decomp. if the shoulder protrudes through by 2.2mm then you must have the shoulder machined down by 2.0mm OK?

your photos don't show me the camshaft boss clearly because picture 2 is an 'end on' photo.



ede April 24th, 2017 02:53 AM

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Thanks Taffy, I'll check it.

Before installing the new lever, I started inspecting the issue, to figure out what exactly caused the problem (sometimes the electric start could spin the engine, sometimes not). The old decomp-lever doesn't move the full angle in certain situations. I think that's because the camshaft including the camshaft-bearing (ignition side) have an axial play of about 0.4mm (see picture below left). On the camchain-side the camshaft slides inside the inner ring of the bearing (picture below right). The bearing (camchain-side) itself is fix. When the camshaft moves, the decomp-lever wears against the bearing and the lever stucks. The decomp-spring is not strong enough to get over that point, even not when it's preloaded. When pushing the camshaft a little to the ignition-side, the decomp-lever moves quickly.

Anyway, since the new decomp-lever is shorter, I hope that even a little axial play will not cause the lever to stuck again.

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