Another wont start question

[Quicky1980]

I have the infamous 2002 400 FSE engine and have the dreaded wont start issue.

The bike came to me like it and Im in the process of trying to sort it.

I was told by the seller that the bike can be pushed started but I have been unable to confirm as I don't have any hills near me nor a suitably grippy floor to make a good enough run at.

I've left the battery on charge with my battery tender so I'm thinking the battery is to a suitable charge. Battery age and condition isn't clear but a receipt indicates it was changed early this year.

When I use the electric start the engine turns over and I can hear the engine compressing and sometimes get a misfire/back fire but no start. I smell fuel from the exhaust and hear the fuel pump priming so I think its injecting.

I've tried kick starting it a few times but again, no luck.

I'll try and get a video up to show the engine cranking on e start.

Any ideas? I've heard that valve clearance might be a root cause, another idea was an auto decomp valve?? Never heard of this valve so could do with a bit of guidance on what this is, likelyhood of failure and where it is (how is it to fix).

Thanks ahead.

[Quicky1980]

Right, got the bike started today by using jump leads from a car battery. The bike eventually fired but it did take a while. Plus as it cranked the engine speed could be heard speeding up to almost the point of firing but then I hear a mechanical hit, almost sounds like the starter jams.

I took off the cover plate of the lhs and all looked ok, ie no broken gears, pinions and the sprag seems to be doing its thing. I couldnt do proper sprag clutch check as I couldnt get the part in front of it off.

Ill try a brand new battery to see if it resolves the issue but the mechanical jam/hit worries me. Any ideas?

[jostby]

hopefully just pre-detonation while trying to start with the weak battery. The fuel injection requires a very good battery (and connections) as the electronics need 12v to fire while the starter will still crank with a poor battery when less than 12v. A week battery (even with jumpers) could be letting the spark come and go to cause your issue.

[Quicky1980]

thanks Jostby, I did see alot of search hits on here saying that these early efi's needed loads of voltage during cranking.

have ordered a new bosch battery, 507 902 011 I'm hoping this is the best/correct battery. At the price Ive just paid ?80 pre discount I would say this battery should have plenty of cca's!

Will hopefully put the battery on tonight and see if the mechanical sound goes and the starting issue is resolved. If its sorts it I'll leave feedback to allow for closure of this post.

[Quicky1980]

Fitted the new battery and it now starts...just. There is still something not quite right as it can be a struggle to start.

I'll give the bike a proper service and check the valve clearances whilst im at it. thanks again for your input/help.

[Quicky1980]

Right gave the bike a oil filter, air filter, spark filter change and still no improvement to the starting if anything its now harder

Timing clearance is as follows

Exhaust
0.25 0.3

Inlet
0.2 0.1(if anything, lower than 0.1 but couldnt measure)

Are these clearances within tolerence? Could they be causing the bad starting?

Im going to renew the starter this weekend hopefully but am unsure if I should go to the bother of rehimming.

Only had the bike a short time and already its getting really frustrating.

[luzt]

Originally Posted by Quicky1980

Right gave the bike a oil filter, air filter, spark filter change and still no improvement to the starting if anything its now harder

Timing clearance is as follows

Exhaust
0.25 0.3

Inlet
0.2 0.1(if anything, lower than 0.1 but couldnt measure)

Are these clearances within tolerence? Could they be causing the bad starting?

Im going to renew the starter this weekend hopefully but am unsure if I should go to the bother of rehimming.

Only had the bike a short time and already its getting really frustrating.

I have the precise same problem as you, any updates?

[wakeymatt]

we all have this problem, is it possible to update the CDI to something less spark hungry ?
I'm looking into carbing options as i've had it with this problem child but it would be nice to find a solution so I could at least sell the bugger !

[wakeymatt]

just found this, perhaps a mcct might work - http://www.gasgasrider.org/forum/sho...highlight=mcct

[cal_tony]

Somewhere back a couple of years ago I did mention on this site that the DRZ manual cam chain tensioner will work on the GG 450. Not sure about the current price but usually the Thumper Talk store has them for about the mid $40 freight paid.
I have one on one of my GGs(the one that has a hard time with the morning start but always starts trouble free for the rest of the day). On my other GG I use a Cam chain tensioner from one of my DRZs.

Tony