Running kinda! Back fires and dies....

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U_h0rnet5
zxr400 oc member
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Running kinda! Back fires and dies....

Post by U_h0rnet5 » Mon Jul 17, 2017 3:24 pm

Afternoon all,

Been a while since I have been on here because of a new arrival. Now I have got a bit more time spare so I thought I would get the bike back on the road!

Bit of background info:

Bike has been sitting for a few years, but has previously ran and from what I remember it ran fine with no problems. I sprayed some carb clean into the carbs and given it a service:
New Battery,
New Sparks,
New Fuel Filter
New Fresh Fuel,
New Air Filter
New Oil and Oil Filter

After trying to start the bike up for a while it finally turned over and started up on the choke. Sounded a bit spluttery but after was alright. I noticed some white smoke coming from the exhaust headers, smelt like clean burning! No oil present, I had previously sprayed the bike with WD40 so could be of been that.
I turn it off may had back fired then, took the side panel off to inspect the headers. Tried to start it up again and heard a clunking sound as it turned over as if it was getting stuck! I checked the oil level and topped it up (it was already halfway on the view glass) it did turn over and would run but back fire quite a bit. When running holding the throttle the bike runs fine, opening the throttle a little more the bike ran fine but letting go or backing off it would then back fire and completely die!

Where should be my first port to call:

CDI
Timing
Carbs

Any help would be great?

Thanks,
Ciaran

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Miles
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My Bike: ZXR 400 L3
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Re: Running kinda! Back fires and dies....

Post by Miles » Mon Jul 17, 2017 10:16 pm

Your timing can only change if it's been altered. As the bike has been laid up for awhile I would say , like 99% of problems with these bikes, it's the carbs.

Get them off and stripped down, full clean and set to factory settings. Then go from there.

As for the white smoke, if it's not coming from outside the engine, check your oil for water. Could be a head gasket leaking.

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U_h0rnet5
zxr400 oc member
zxr400 oc member
Posts: 290
Joined: Mon Jun 26, 2006 11:48 pm
My Bike: ZXR400
Location: Watford
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Re: Running kinda! Back fires and dies....

Post by U_h0rnet5 » Tue Jul 18, 2017 10:36 pm

Perfect I thought as much, if I change the CDI unit from a 'M' to 'L' would that make any difference other than the fact that the rev limit changes?

User avatar
U_h0rnet5
zxr400 oc member
zxr400 oc member
Posts: 290
Joined: Mon Jun 26, 2006 11:48 pm
My Bike: ZXR400
Location: Watford
Contact:

Re: Running kinda! Back fires and dies....

Post by U_h0rnet5 » Sun Aug 06, 2017 8:39 pm

Well I think I have found the problem some idiot had put the HT leads in the wrong spark plug!!!! Dunno who that could be :smt017 lol.

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