250 fuel starvation

[Tonykat]

Hi, got my 250 back from garage after been checked over and carbs cleaned, but still not needing choke to start and running rich, went for my first ride on it, ok for just over a mile, then pop and bang and cuts out. Would not start, good spark and fuel getting to carb but not getting to cylinders, plugs dry but black, rac took 4.45 hours to arrive then another 4 hours for recovery, not a good day. Will be going back to garage.
There was no misfire so guess blockage around t piece feeding carbs.
Tony

[fossie]

Floats , the o ring around the fuel inlet to float bowls is perished or damaged. Are they at least new or viltron?
Are you using E10 petrol? ( don't ever in a pre 2000 bike ) .

RAC are absolutely crap when it comes to bikes ...they have no facility and sub it out ..4.45 hrs is good for them ...I've had to use them for work bikes .. 12 hrs first time ..6 second time 3rd time again 6 hrs forth time ....I pushed it 3 miles back to yard , it was still quicker than their quoted time , which is pye in the sky anyway!

[Smallkat]

I guess if all plugs are dry, it must be a supply problem. Is the fuel tap vacuum pipe in good condition? Just to eliminate one more thing! That pipe must be the correct type and not regular hose. It has very strong walls.

Is the started mechanism working properly?

You'll have to run methodically through the whole system, I'm afraid. I had to do the same with Tinykat.

When you say carbs cleaned, do you mean ultrasonically?

[Tonykat]

I am hoping it may just be the filter, checking it tomorrow, don’t think it’s the vacuum pipe because it doesn’t run in prime. Carbs not been ultrasonic cleaned.
Thanks for the advice

[Kryten]

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RAC are absolutely crap .....................

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I concur. When my Speed Trip packed up due to a fuel pump issue, it took them 4 1/2 hours not to come out to me and then they promised me that they would be with me by 02.30, maybe.....I pushed the bike to a mates house and Fred61 gave me a lift home. It would have been quicker to just push the thing home in the first place

Kicked them into the long grass when it came to renewal time..

[fossie]

For me the first thing to do is try a new set of plugs ...if it starts ok then it's the carb mixture .
You say the carbs haven't been ultrasonic cleaned ...if it's been standing without the carbs being drained ...you're pissing in the wind ....these carbs have so many really small chambers / passages that block up.

For interest sake is it a genuine zorst and airfilter.?

Black plugs is over fuelling , and running so for a while will clog the plugs ....modern plugs don't like being wire brushed clean like the old series , so won't really give a good result .
Possible reasons are sticking floats or seeping floats , or choke ( cold start ) system stuck open even slightly

[pookie]

When I first got my 250 Kat it took an age to fire up, after it eventually started it was fine, the problem was a tiny hairline crack in the vacuum pipe letting air in, I also fitted NGK iridium spark plugs (code CR8EIX) after having the carbs ultrasonically cleaned and viton synthetic o-rings fitted, and I always use Esso supreme unleaded fuel as its supposed to have no ethanol in it if you buy it south of Watford, as I knew It was going to be a keeper I tried to future-proof it as much as I could, it still fires up and runs great over eight years later

[Smallkat]

Pooks, you really are the exception and you are just lulling people into a false sense of security! Then you add insult to injury by adding a picture of your immaculate 250.

Seriously, take the carbs apart, give them a really long clean in an ultrasonic bath, fit the Litetek O ring kit and then you might be in with a chance. Check the pilot screws are set correctly and the O rings are good. I reassemble with a tiny dab of grease. These are quite delicate and easily damaged.

Other things that *might* be a problem:

Make sure the side stand switch is working properly or disconnect it and wire on permanently. On my 400, if you went over a big bump, it would temporarily cut the ignition. I bent the stand tang a bit, which cured it.

The Igniter may be on its way out. Sometimes works, sometimes not.

Kill switch wiring could be intermittent. Check for wire breaks.

I use premium E5 unleaded with Star Tron fuel treatment. Probably voodoo but up here in the Northwest the premium E5 could still have ethanol.

I use iridium plugs, but did not notice any difference between iridium and normal.

[pookie]

Think the iridium plugs last longer, which is great 'cos getting them out and back in again can be a chore (had to buy a very thin plug socket from e-bay) sorry Smallkat, don't mean to keep putting pictures of my bike on here but the only thing better than riding a 250 Kat is looking at one

[Smallkat]

Yes, the plug tunnels are a nightmare. I ended up with a slim plug socket with a short extension. Even then the inner cylinders are a bit of a pain. Can you remember which plug socket you got off ebay?