Starting problem and a question

[utternuttercallum]

Hi all,

Ive just bought a lovely new zxr. Its a 1990 model thats all i know, i think its there fore a H model. its sat with the prvious owner for a year and now although everything works fine, it wont start. it turns over and Coughs a bit and does the occasional backfire but thts it. there is petrol in the tank from its last use, ive been told its just stale and that all i need is to drain it (i was going to use a siphon) and to refill it then to turn it over to pump the new fuel in. any one have ideas or similar problem? also i want to know how i can tell if its restricted, what that means, and how i can override it.

thanks everyone

Callum

[RedexRobB]

Hello and welcome to the forum!

Yes its very possible the fuel has gone stale. It turns into a gunge after a few years and the best way to clean it out is to get the carbs off and get them apart for a clean with some carb cleaner. I would then suggest running a bit of redex through for a thorough clean! Additionally, drain the tank dry of fuel and start afresh.

Regarding the restriction, all info here:

viewforum.php?f=164

If you have them, you ll have some washers between the inlet rubber and the engine block. youll see them ifyou take the carbs off to be cleaned.

[utternuttercallum]

thanks for your reply i have today siphoned my fuel out and refilled the tank. it still turns over and backfires but wont start. would it be worth simply changing the spark plugs first? im not very mechanical so carbs is costly and im now broke than to insuring it haha

thanks

[RedexRobB]

Yep, thats another thing actually, take a look at the plugs. Get them out, clean and reset the gaps.

[parby81]

although you've drained the tank, the carbs will still be full of old stale fuel. you should drain those too, little screw on bottom of chamber of each carb. Then try turning over. this will take a while as carbs need to be refilled with fresh fuel. When i say some time, it could be enough to flatten your battery.

[Mori Man]

can of "easy start" , remove airfilter and spray inside while turning it over - remove the tank and use a big jam jar full of new petrol and you can see it being sucked up and priming the carbs.

Bin the plugs and put in a new set too.

You get carb cleaners (most of them) you use while the bike is running and like the easy start you spray into the carbs while the bike is running, just keep topping up the jam jar

You can also put Rob's favourite - Redex into the jam jar too and make it a fairly strong mix (dont use neat) , I use a 500g jar and the bike uses that up within 5mins of running, it is half gone once carbs are primed though.

I put Redex into my tank every 3 months or so - just to keep things clean

[utternuttercallum]

i got fresh petrol in tank now. I looked at the service manual, it doesnt look too hard to take the top off nd empty them nd give them a wipe out. thanks for the input, ill probably try the easy start and redex thing at the same time as well to be honest

[cargo]

taking the top off the carbs will not empty them.....................

[utternuttercallum]

but i guess once the top is off you can access the floats and empty them manually with a syringe or similar?

[Mori Man]

but i guess once the top is off you can access the floats and empty them manually with a syringe or similar?

That's keen - you would need to remove throttle valve with needle then have a 100mm needle on your syringe finer than the jet needle coming out of the carbs so it can pass down the emulsion tube and out the main jet then into the float bowl. If the MJ is #95 then your syringe needle needs to be smaller than this to pass through.

The drain bolts aren't hard to access and less work than removing the caps.

[cargo]

I am stuck for words....................

[utternuttercallum]

id strip them down to the float bowl so as to wipe out the crap and gunk from in the bowls though wouldnt i? as i say to be truthful i have onli the mechanical knowldge from watching a mechanic working on my old VFR to do the same to carbs and clean the jets. also i have fine needles, my mums a nurse lol

[parby81]

You need to be careful off your use of english

"but i guess once the top is off you can access the floats and empty them manually with a syringe or similar?"

the float bowl is on the bottom of the carb!! which is where the drain for them is. As MM said far easier to drain them. Don't start dismantling carbs unless you know what you're doing. To rremove the float bowls, you'd want to take the carbs completely off the bike to give it all a thorough clean out.

"to be truthful i have onli the mechanical knowldge from watching a mechanic working on my old VFR to do the same to carbs and clean the jets"

If I was you, I'd start simple then, and draining the carbs and then following MM's advice on start up is a good way to go. Don't over complicate things.

[utternuttercallum]

[quote="parby81"]You need to be careful off your use of english[quote]
i dont understand what you mean by that but clearly so do you. i am asking about different ways and such so that i can learn better. starting simple is all well and good but wont help me learn more. the other good thing about asking for different methods is this way i can compile a variety of methods and choose the one i like best and i think would be best for me. after all, its my bike. seeing as i have to take the fairing and tank off anyway for other bits i need to do i figured while it was open i may as well take the carbs off. ive been told now by about 3 different mechanics that simply removing all the carbs as one from the float bowls is simple and wont cause any problems syncro wise. just wondering if anyone else agrees?

[parby81]

you're right that should be "of" !! basically you said go in from the top, we are saying float bowls are on the bottom so you need to go in from the bottom.

Enough on that though.

As far as syncro goes, and by this i presume you mean balancing, then personally, I would re balance the carbs evry time after I have fiddled with them. If only resting the screw driver that you would use to balance them on one of the balancing screws can throw the whole thing off, then what do you think removing the carbs, fiddling with them and then pushing them back on is going to do? Down to personal opinion really.

All of this aside though, have you done the whole draining down route as has been suggested to actually get the bike goin?