Slow Steve
Post Posted: Wed Jul 31, 2019 10:19 pm
 Subject: Carb issue

Hey all! Another new guy here. I got the itch to ride again and thought I'd pick up a 06, 250. I've done some track riding and have owned bikes from KLR650 to a Monster. I picked up this bike cheap and thought I'd put some time into it and enjoy getting on two wheels again.

I can get the bike to start if I spray starter fluid in so I figured it was a fuel issue. I put some fresh gas and pulled the line off after the petcock and cranked it over, fuel began to flow so I figured petcock was good.

So I pulled the carbs apart and cleaned them out. Found some clogged jets (the usual). Checked the slide diaphragms - no cracks no tears. So I put them back together and still doesn't start.

Spray starter fluid - starts.. disassembled again. re-cleaned, blew out all the passages - everything blows through and reassembled.... still doesn't start... Spray starter fluid - starts.. then dies of course.

Anything I'm missing? Can the slide diaphragms be bad even though they aren't torn or damaged? Anything I can try to eliminate something? Def seems like a fuel issue..

Any help would be great and much appreciated!
GeorgeRYoung
Post Posted: Thu Aug 01, 2019 8:07 am
 Subject: Carb cleaning

For starting, it's critical to get the pilot jets and the holes under the butterflies clean and free flowing. See

https://faq.ninja250.org/wiki/Cleaning_the_carbs_2

The slides don't have much effect on starting.
Slow Steve
Post Posted: Thu Aug 01, 2019 12:17 pm
 Subject: Carb issue

Good link, THANKS! I've taken them completely apart and have one dipping in chem stuff. I used the spray carb cleaner before and blew out the holes with my compressor. But I'm completely disassembling them this time. I'll let each soak for an hour while agitating them now and then. The only thing I haven't taken off is the plastic fuel elbow. I'm not sure if I can dip that without hurting it. Any ideas? I'll keep searching the net. I may be able to dip it seeing how the basket in the gallon of dip is plastic.
Slow Steve
Post Posted: Thu Aug 01, 2019 5:02 pm
 Subject: Running now, but surging at idle

SHE RUNS!!! I'm stoked, but now I'm chasing an erratic idle. I'm going to get some new plugs; probably has nothing to do with it, but still going to change them out. I wonder if it's bad gas. It's been sitting a while. Why'd I buy a bike with carbs?! haha

I guess surging is what I'm trying to say. I've looked around and it seems I still have some blockages. I'm hoping bad gas, but It's getting better so I'm stoked about that. But may have to take apart the carbs again.
jkv45
Post Posted: Fri Aug 02, 2019 9:27 am
 Subject: Adjustments

You didn't mention the Idle Mixture screws or adjustments - did you remove the screws, clean the passages, and check the condition of the o-rings? They should be set to 2.5 turns out for starters. That's generally richer than the factory setting and helps get a smooth idle.

Did you sync the carbs? Another important step in getting a smooth idle.

I'd also check for a vacuum leak between the carbs and engine, as that will cause a lean condition also.
Slow Steve
Post Posted: Fri Aug 09, 2019 12:58 pm
 Subject: Leak

I def have a leak between the carbs and head. I sprayed start fluid between the two and the engine raced. Any suggestions on places to order them?
jkv45
Post Posted: Fri Aug 09, 2019 1:21 pm
 Subject: Manifolds

Slow Steve wrote:
I def have a leak between the carbs and head. I sprayed start fluid between the two and the engine raced. Any suggestions on places to order them?


Are they checked or cracked, or are they leaking at the ends where they seal?

If you need new ones, there are plenty of choices online.

We had a 1990 Ninja that had a rough life but the manifolds were fine, so I'd say you could find some decent used ones if new ones are expensive.
Slow Steve
Post Posted: Sun Sep 08, 2019 11:37 pm
 Subject: Running smooth now

Just wanted to give an update. The bike is running smooth as butter now. So after looking into how the carb actually works and a post above saying the slides had nothing to do with starting or idle. In the past I just soaked the carbs and aired them out and BAM! good to go, but not this time. They were clogged good and a vac leak at the boots between the carbs and head. The boots were compressed as the clamps were bottomed out metal to metal and still weren't tight enough. I put one clamp on the boots at a time and after each the bike ran better and better until it was idling and revving right. Took it for a ride and HAPPY DAYS!! Thanks for the responses and tips. I really do appreciate it.
Slow Steve
Post Posted: Sun Sep 08, 2019 11:37 pm
 Subject: Running smooth now

Just wanted to give an update. The bike is running smooth as butter now. So after looking into how the carb actually works and a post above saying the slides had nothing to do with starting or idle. In the past I just soaked the carbs and aired them out and BAM! good to go, but not this time. They were clogged good and a vac leak at the boots between the carbs and head. The boots were compressed as the clamps were bottomed out metal to metal and still weren't tight enough. I put one clamp on the boots at a time and after each the bike ran better and better until it was idling and revving right. Took it for a ride and HAPPY DAYS!! Thanks for the responses and tips. I really do appreciate it.
jkv45
Post Posted: Mon Sep 09, 2019 8:47 am
 Subject: Good to hear!

Greg737
Post Posted: Mon Sep 09, 2019 2:59 pm
 Subject: You may already know this, but I'll mention it anyway...

You do know that the carb-to-cylinder head boots have a proper direction of installation printed on them?

One end of each boot is marked for the carbs and the other end it marked for the cylinder head.

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