1985 250r carb issues

[Auto_Demon]

So just recently my 250r sounds like its not getting fuel, it was running perfect earlier today and now when u give it gas it bogs and dies, took the carb off and cleaned everything, cleaned the in tank filter, shortened the fuel line and put an inline fuel filter in and its still doing it, ive also noticed that there is an air bubble in the fuel line but its still getting fuel, what is going on? Can anyone help me?

[yaegerb]

Possible your jets are too big?

[Auto_Demon]

Nope cuz it was running fine the day before and i did nothing to the carb, it was running good, we switched out tires and rims and then it started doing this

[barnett468]

Hello Auto Demon




So just recently my 250r sounds like its not getting fuel, it was running perfect earlier today and now when u give it gas it bogs and dies,

When it “bogs” does it burble/stutter like it is rich or does it simply fail to build rpm like it is running out of gas?

Pull plug out when it dies and see if it is wet.





took the carb off and cleaned everything, cleaned the in tank filter, shortened the fuel line and put an inline fuel filter in and its still doing it

Pull hose off at carb and see if gas flows quickly or slowly. Try it on maain and reserve. Gas valve might be partially plugged. Fuel filters are occasionally restrictive but since you had this problem without the new filter it is likely ok.





ive also noticed that there is an air bubble in the fuel line

It’s strange but they always do, it is not a problem.




GAS LEVEL TEST – If your gas level is low in the float bowl then your carb will be lean and may run out while riding mainly if there is a restriction in the line from tank to the bowl or at needle and seat.

Install clear plastic tube on bowl drain, hold open end of tube level with top of carb and open bowl drain valve. The gas will flow into the tube. It should be from level to 3/16" below the bottom of the carb body where it meets the bowl. If it is incorrect then adjust float accordingly.

Now tape that hose to carb, leave drain screw open and test ride. As soon as it dies look at gas level in hose. If it is low or empty then find fuel restriction.

[Grahm]

What does your spark plug look like?That will tell you quite a bit.Post a picture of the plug.Could be running rich and just
finally fouled it.

Mine did the same thing.Ran perfectly then all the sudden had erratic idle,bogged down,sometimes would start sometimes
wouldn't.
Found my plug was fouled.Changed it and have been fine since.

Heres a chart to help-

http://kereta.info/wp-content/uploads/2009/07/spark-plug-colour.jpg

[Auto_Demon]

Didnt think it was fouled but now looking at that chart it looks like the plug is carbon fouled, ill post a pic anyways a little later. So ill replace it and see

[Auto_Demon]

I believe its still running a bit rich but i dont know what else to lean it out with. The clip is on the highest notch on the needle, and i am running 32:1 ratio, and i have no aftermarket parts on it...yet, should i try removing the airbox lid?

[Grahm]

What plug you running? BR9 OR BR8 ?

[Auto_Demon]

Br9es plug

[barnett468]

Hello


If the plug is black and dry [powdery] it is rich, it it is black gooey and moist even the least bit it is burning oil and possibly rich.

Does it smoke?

Lots or a little?

What color ids it, llite blue/gray or dark/black?

Removing the air box will lean it out slightly on top end.

You need to replace your plug or scrub every bit of black off it or it can miss fire.

[Auto_Demon]

Forgot to take a picture of the plug before i cleaned it, doh. But the plug was black and dry, looked like it had carbon buildup on it

[82 250r]

The clip is on the highest notch on the needle
That's pretty lean unless your riding above 7000 ft.
Try the clip on the 2nd or 3rd from the top.

[Auto_Demon]

That's pretty lean unless your riding above 7000 ft.
Try the clip on the 2nd or 3rd from the top.

It was on the 3rd clip but it was too rich even at 32:1, i might have torun 50:1. I was running that on my 83 250r woth the clip on the highest notch and it ran perfect

[82 250r]

It was on the 3rd clip but it was too rich even at 32:1, i might have torun 50:1.

32:1 works well for these machines...stick with that. Don't jet your trike with fuel/oil ratio.
If it works well on the top clip, you are probably compensating for another problem imo.
Things to check before jetting are:

Compression
Air Filter
Reed condition
Condition of electrical components
Float height
Pipe and silencer clogged
Air leak

Any of these can have you chasing your tail with jetting.
I would start with the factory jetting after checking all of the above.

You may want to look on ebay for an 86 34mm pj flat slide carb...those 85 pe round slide carbs are known to have issues.

Hope this helps
Marc

[Jason Hall]

Does it have the original (carb Round slide)?? If it has a oval slide (idle adjustment on choke knob) from a 86-89 Atc/Trx then could you have the slide in the carb with the cut out facing forward. That will make it run rich as heck especially when idling, and up through half throttle.

[atc007]

If this bike was working perfect as you say,then threw this fit, Nothing changed mechanically in your carb. Jetting or otherwise. Fuel blockage,ignition or air leak is what you're looking for. Start by putting in a brand new B9ES. Get that resistor out of there unless you ride around a lot of neighbors. I learned that by late fall of 84. They do NOT like the resistor plugs.

[Auto_Demon]

Does it have the original (carb Round slide)?? If it has a oval slide (idle adjustment on choke knob) from a 86-89 Atc/Trx then could you have the slide in the carb with the cut out facing forward. That will make it run rich as heck especially when idling, and up through half throttle.

I dont know what carb this is, its a 36mm flat slide carb, it says oem std on the side, the guy bought this one because he said it wouldnt run with the original carb

[Auto_Demon]

UPDATE. so its not the plug, im thinking its something electrical. took it for short ride today and it was doing the same thing, sputtering, bogging when u give it gas and itll like burp and jerk when u give it gas and it started backfiring then it would just die. any ideas?

[Auto_Demon]

http://www.youtube.com/watch?v=i2Eml0KEvXY here is a video of whats going on

[atc007]

Check your kill switch? Then,If you know anyone with another 85 R , swap CDI boxes. If no difference, coil, if he's open, then stator :).That's a good start,then you'll have to start troubleshooting from there.. Again, assuming all fuel delivery components are correct.

[barnett468]

Hello




UPDATE. so its not the plug, im thinking its something electrical. took it for short ride today and it was doing the same thing, sputtering, bogging when u give it gas and itll like burp and jerk when u give it gas and it started backfiring then it would just die. any ideas?

First of all it sounds rattly like major piston clearance and/or balancer bearing. Do you know anything about the bore?

Also sounds like a lot of compression, can you do a comp test. This isn’t your problem just want to make sure you don’t need race gas.

Also suspicious that he said it needed new carb and even though it ran fine briefly it now has problem again, who knows?

Snip 1/4” off end of coil wire at plug boot then reinstall, that’s sometimes a problem.

I would do my test in post 4. If you don’t test anything it won’t get fixed. A float might have stuck or got debris in needle and seat. Start simple.

Check for air leaks as mentioned using flammable carb cleaner and long nozzle. Spray gently around intake boot at carb and reed valve. If idle goes up it has a leak.

If you pass these 2 tests it might be a seal leak, might need to do leak down test.

Next is electrical most likely ign coil or CDI box. Check coil and exciter coil in stator with ohm meter.

Check voltage out of exciter coil by removing plug, lay it plugged in on head, have someone hold voltmeter while you kick. Might read around 30 or more.

If you pass these tests I would buy a CDI.

[Auto_Demon]

Motor has never been touched and the compression is at 170psi

[59GMC]

would the cdi/coil off an 83 250r work for trouble shooting purposes or r they completely different?

[barnett468]

Hello Auto Demon




Motor has never been touched and the compression is at 170psi

Ok, thats good




atc007


Sorry, didn't mean to almost duplicate part of your post. I didn't see it.

[Auto_Demon]

Guess i should have mentioned this before but these symptoms only happen when the engine warms up, when its cold it revs fine

[barnett468]

How many minutes does that take to run bad?

How long does it take before it runs good again?


If it takes more than 40 minutes remove cdi then put it in the bottom of the refrigerator for 15 minutes, no less. then reinstall. If it runs good again repeat 1 more time if it runs good again your cdi is bad.

[Auto_Demon]

How many minutes does that take to run bad?

How long does it take before it runs good again?


If it takes more than 40 minutes remove cdi then put it in the bottom of the refrigerator for 15 minutes, no less. then reinstall. If it runs good again repeat 1 more time if it runs good again your cdi is bad.

just takes long enough to warm up so 10 minutes ish. when it cools down completely it runs fine for another 10 minutes or so until it warms up again then it dies

[Auto_Demon]

172708 so i took the reeds off and i found this. but there is no gap between the reeds

[82 250r]

these symptoms only happen when the engine warms up, when its cold it revs fine

I had a similar issue in May...turned out to be a bad stator.
When it's cold, it had spark and would start fine, run normal for 2-3 minutes, then quit and not start again.

Try a known good stator.

[barnett468]

172708 so i took the reeds off and i found this. but there is no gap between the reeds

Well they need to be replaced but if there is no gap and it runs good for a few minutes it MAY not be a problem


Put the cdi in the fridge if it takes lomger than the time I mentioned to run good again.

replace reeds before they break further and possibly damage engine.

[Auto_Demon]

if i were to buy a new stator would i need a 200w one? im not sure what the stock one is

[fastatc70]

Have you checked the air filter. Sorry for the stupid question.

[82 250r]

if i were to buy a new stator would i need a 200w one? im not sure what the stock one is
100w is stock...200w is the same except the extra watts are used for the lights...not ignition.
My defective stator was a new "Ricky Stator"...it was good for one (1) ride...put my rusty oem stator back in and works great.

ebay is a good source for parts...guys on the forum sell stuff as well.

[yaegerb]

There are hundreds of threads on finnicky 250r motors over on trx250r.net....have you broadened your search to.that site yet? I would be willing to bet you could find a similar problem and solution through their search feature

[Auto_Demon]

How similar is a 1986 cr250 motor to a 1985 atc 250r? Cuz i can get my hands on one for real cheap if parts are compatible