XJ750 cutting out when cold

Hi guys,
Ive just purchased a 1984 XJ750 and I have a small problem with it just cutting out 3-4 times in a short period from its first start in the day. Once it has got over that shes fine. I have replaced fuel line and filter, and the vacum hose to the fuel tap. Once it cuts out I have to wait 30 seconds to a minute before I can start up again. I have even just had it on Prime and the same thing happens.
Any suggestions as to where I can go from here would be much appreciated.

Cheers

Steve

 

I have an RK model ... mine currently in bits awaiting a rebuild. It did similar. I found a good warm up (about 1500 rpm) helps. Don't try to rush it. Check the plugs too.
My XJ750D starts fine ... and after a short warm up ... ready to roll ..

Getting the start procedure that your bike needs/wants ... has always been the first "new bike" issue.

 

When is the last time you checked your valve clearance?

 

Thanks guys; its recently been serviced, new plugs etc and Ive tried the whole gentle warm up around 1500RPM and she still cuts out 3-4 times. Once its over that she does'nt miss a beat.

 

Does it die under load or just when idling? I don't want to send you down the rabbit hole but it might be TCI related. Need more input

Oh yeah, welcome to the site mate!

 

Couldn't be carb icing for some reason could it? :? Strange one for sure...

 

@mwhite74, it does it under idle and under load; I've just checked the inlets and there would appear to be an air leak. This may be the the reason why it does it when cold. Carbs have all been serviced but looks like they may have used the old gaskets. Thanks for your input guys great to be a member

Cheers

 

Valve clearances are not always included in a "General service". Getting them done removes a few issues with the XJ's ... 30 year old engines need all the help they can get.

 

Sounds like bad carb setting of carbs are dirty. Mine was doing it and a really good cleaning is what corrected my problem.

 

Sounds like it could be my TCI unit
The link below would appear to be the answer but instead of trying to fix it I think I will opt for a second hand one, or one from ERD here in New Zealand.
More homework to be done first as the wire configiration is not quite the same.

http://members.tripod.com/dave_jack/id41.htm

http://www.erd.co.nz/

Cheers

 

When you say serviced what did that entitle?

The first thing on the service manual is to check your valve shims, do you know when is the last time that was done? If you do not I would encourage you to do it, if they are off specs tinkering with the carbs is almost a waste of time.

Good luck.

 

Thanks for your input guys; Im convinced that I have the same problem as Dave from the link below. she doesn't miss or splutter she just dies like you have hit the kill switch and then pretty much starts straight away; he calls it a Dry Joint in the PCB (Printed Circuit Board)

http://members.tripod.com/dave_jack/id41.htm

 

If it were a "dry" joint I'd expect the bike to not run at all/run on 2. You may be thinking of a cracked solder joint, but I'd expect that to let the bike start/run when cold & die as it warmed & the components expanded (this is a common problem on CRT televisions I work on where the vertical deflection fails after a few seconds, and on flat screens when the T-con card fails after warming up, and indeed on PS3's that get the "YLOD" fault). Cracked joints tend to open as they warm up.

Also as it starts straight back up this points more to a carb issue still IMHO. Perhaps the cold start jets in the float bowls are partially blocked, allowing the bike to fire until it uses up the supply & then cuts out, then the "well" refills and the bike starts again, this repeats until it'll run without choke?

 

Installed a new TCI unit today from ERD here in NZ and problem solved, it even idles now from a cold start without me having to hold the throttle.
Thanks for the input guys.

Now to paint her in the original colours!