Leaving.....Again

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ARCHIVE_gosupes

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hard starting when cold

Have a small problem someone can hopefully shed some light on. My 900 has always had a tough time starting when cold or after sitting a couple of days. It always fires on numbers 1 and 3 but 2 and 4 are dead cold for the first couple of minutes. Have replaced plugs and wires, had the carbs apart a couple fo times but never any change. Runs fine once warmed up. I removed the airbox and carbs for an unrelated issue and just re-installed the carbs to check for leaks (will be installing pod soon). I tried to start it but the engine just turned over and there was very little vacuum from the carb throats. I briefly put my hand over the throat one at a time and as soon as the cylinder was able to draw in some fuel it fired. I realize that it might make a difference on ability to draw in fuel with no filters restricting the air, but I am trying to nail down why it will fire 1 & 3 and not on 2 & 4. Something in the choke circuit? Or low cylinder vacuum? Also when going to pods, what to do with emission hoses, which do I remove or re-route? Thanks again.
 
Check for vapor lock, the gas cap vent might be clogged.
 
Although I don't think this will be your problem, I'll spill the beans anyway. Given that the coils supply outboard cylinders together and likewise for inboards, I don't think your problem is ignition (unless of course you have two coincidental problems).

Carbs 1 & 4 are the masters for the fuel enricher system (diaphragms on LHS, held on with two small screws) whereas 2 & 3 are slaves and are connected to their partner with a small diameter crossover hose. If you haven't done so already, check the rubber diaphragms on each and their rubber connecting hoses.

Just a thought, good luck…
 
Had a similar problem (still got it) and I did a compression check on the cylinders. Found out that No's 2&3 had low compression. I haven't done anything about it yet as I decided to run it through the summer and do it as a winter project.

Seems to be using a lot of gas with it as it is, but hasn't seemed to make much difference to performance.

KK
 
Thanks for the responses. Haven't done a compression check yet but a tester in on my list of things to get. As for vapor lock, I will blow some air through the vents and make sure they work.

Rocket: There is no diaphram on the side and the only cross-over tube looks to be a vapor/emissions type of line. Am I missing something?
 
Gosupes,
Sorry, it appears the ZL900 doesn’t have these fitted on their carbs (I can sleep tonight knowing I’ve learnt something and the day wasn’t a waste after all).

In case yo were wondering what I was on about, take a look at this pic (http://www.bikepics.com/pictures/325662/) and you'll see it at about mid-section of the slider, it looks like it has a hole in the centre. You may also note the (black) hose running over the top and to the rear. This hose connects the RH partner carburettor to the top of this vacuum diaphragm.

For others reading this (now or in future) who may discover a problem with theirs, BikeBandits (www.bikebandit.com) lists it as a ZL1000A1 Part No 43028: DIAPHRAGM, AIR CUT VAL (591253-001) for both models (US and CAL). Unfortunately they don’t list the ZL900.
 
Taking off on Sunday June, 17th and will be gone for 7 days, Rachel and I are going to council the 2nd thru 5th graders at a Christian summer camp...Wish me luck!!!
moab...
 
Did you ever see the movie Uncle Buck? LOL!! Somehow that movie comes to mind..... have a great time.
 
Have fun moab! Sounds like a challenge for sure! You get done with that you will needing therapy!
 
This will be the 3rd year, I have a ball, but I am just shot by the time the week is over.....Uncle Buck, now there is a film I haven't seen for ages, too funny...Thanks for the well-wishes, Eliminator faithful!
moab...
 
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