aviator79

Cleaned carb DR250 and small jet in float bowl IDK what its for? 1990

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Posted (edited)

So DR250 I bought last year with supposedly had really low miles and plastics and such seem to say that was true. Had corrosion but was told it was stored in really damp area; either way ran great but would have starting issues here and there as kick only.

So it started up a few months ago but would not stay running and ended up killing battery and gave up on it as was busy.

Charged battery and again will start but wont stay running.  Gas is a year old but flow thru petcock so pulled carb.  Cleaned up up but confused about this small "jet" that IDK where it goes.  I do not see it on any part diagram so not sure if it was just bouncing around in bowl and does not belong on the carb at all or what.

Any idea?

It has a hole thru it like a jet and it fits on the end of the rod that comes down thru top on spring shown in pic but how it would get from there to bowl IDK.  and not sure it make since being on the end of that rod as what would hole thru it do plus it could fall off plus it is not shown in part diagram

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Edited by aviator79

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if there are threads on it and a slot for screwdriver, check the air jets numbers 35 & 36 on first parts picture

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Nope and all those jets are in place and I blew carb cleaner thru them all and seemed good.  I can get more pics tomorrow.

Installed and still doesn't want to stay running but seemed to run better for few seconds it did run.  Draining gas tank and will try new gas tomorrow. Gas smelled a bit bad but im not expert on gas smell so not sure if that is issue.  Gas is a year old and bigger tank so never fully empties so im sure it old, but not sure it actually the problem.

Id like to get a carb rebuild kit but not spending $40

http://www.ebay.com/itm/SUZUKI-DR250-CARBURETTOR-CARB-REPAIR-KIT-1990-1995-/401310898646?_trksid=p2385738.m2548.l4275

As that does not even include much.  

See how float valve has pin thru it than a rubber end rather than normal solid metal.  That is how mine is and I did not remove so that rubber could be shot and causing flooding...

I was unable to pull choke out as need thin wall 14mm and id like to if spending $40 seems I could spend a bit more and get a new carb so will just look into that I guess.

 

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ok it might be the jet that resides in the end of one tube in the float assembly. i've seen them with & without that jet

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Im not sure where this jet goes. Bike still wont run. Only place it fit was on end of needle jet which comes down from top of carb so idk how it would have got in float tank. Diagram does not show it.

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Posted (edited)

This is the only place it fits, on end of needle jet (last pic) but that cannot be right.  Then needle cannot go down and I doubt it will even go together...IDK.

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Edited by aviator79

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Posted (edited)

Found this post:

http://advrider.com/index.php?threads/anatomy-of-a-dr350-carb-help-with-nomenclatures.497917/

IDK if ok to post link to other forums but DR350 basically has same carb other than that needle valve AFAI can tell.

My float was stuck. Cleaned and replaced float needle valve housing o-ring, #24 (13374-35C00) (Mcmaster Carr 9263K137) with one I found off HPFP sensor that fit OK as mine was shot.  The other float o-ring #19 which feed a jet at front of carb is also bad (1337446710) so I will have to buy new ones.

Bike started and rode fine after it warmed up but still hard to restart.  Could be that bad o-ring flooding crank but IDK.  My leg is too shot to try kicking it over when it wont start easy so did not try very hard.

I have no idea why that jet in first pic was in the float tank.

Edited by aviator79

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Posted (edited)

i posted earlier it may be the jet that resides inside the float assy. you can just see the end of it in the float tube:

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glad you got it running

 

Edited by plugeye
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Posted (edited)

4 hours ago, plugeye said:

i posted earlier it may be the jet that resides inside the float assy. you can just see the end of it in the float tube:

 

glad you got it running

 

Oh, I did not understand what you meant but now I see.  I will have to order the o-rings and then I will put that jet pack in place hopefully can get it to stay.it 

I guess it is not so much a jet as a restrictor.  The tube that it feeds in the carb already has a very small orifice but I assume this serves some purpose.  The o-ring being bad where the float connects to carb where that tube sticks out could also be causing problems. 

THANKS!

Edited by aviator79
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That is where I was going to get them.  Cycle shop has the float needle housing for $6.  I just need to figure out what other o-rings are the same between 250/350 as a quick search shows that the DR350 uses 09280-12008 on crankcase oil line whereas 250 uses 0928012009 on crankcase.

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I just verified all the 0-rings are the same for 250 minus needle 13295-29900 which 250 does not have and THROTTLE-SLIDE-GUIDE.  I also did not purchase starter or rear shock head o-ring as have no starter and not doing rear shock even if they are the same which ive no idea as they do not list PN but they probably are so I probably should have bought but oh well.

$11 shipped.

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Posted (edited)

Put jet/restrictor in and made sure it would stay.  New o-rings.  Bike still wont start and run right...

IDK why I cannot delete pic I uploaded by mistake.

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Edited by aviator79

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Posted (edited)

So just took dr250 for a ride. Same issues. It seems to only start w/o choke. And needs starting fluid. Wont idle until warm which is normal but ussually would half choke until warm?idk maybe always that way. Really slow to idle down from revs which to me clearly indicates carb issues. Possibly throttle cable issues... It is a bit hesitant. Rides ok but seems low on power as far as i can tell though ive been on drz400 mostly so i know its slower but it definitely is not running right.

Seems that it is clearly gas/carb issue. Thinking air leak so rich off throttle and lean on? ...idk.  Will have to pull carb again i guess but ive no idea what to try as there are no adjustments.

Edited by aviator79

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Take a close look at the rubber diaphragm that connects to the slide - those are vacuum operated and are very sensitive. When you open the throttle with the cable, the second slide has to lift too or you won't have any power to speak of. Sometimes there is a poor seal where the rubber meets the carb body - try some grease in the groove to see if this helps. Little problems in carbs really cause a big running issue on a single cylinder engine!

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On 8/18/2017 at 7:28 PM, doug the slug said:

Take a close look at the rubber diaphragm that connects to the slide - those are vacuum operated and are very sensitive. When you open the throttle with the cable, the second slide has to lift too or you won't have any power to speak of. Sometimes there is a poor seal where the rubber meets the carb body - try some grease in the groove to see if this helps. Little problems in carbs really cause a big running issue on a single cylinder engine!

I do not think there is a leak on the top of carb.  When I hold the slide up for a minute it still comes right back down.  Sprayed soapy water around top seal while pushing slide up and no bubbles so I do not think there is a leak in diaphragm of upper seal.

I am rebuilding the carb again but am about to call it. Bought a new float valve and gasket kit but I think the choke really needs to be replaced as the boot is shot and at $30+ a whole new carb would just make more sense if I knew what carb to buy.  

I have taken it all apart; removed choke, diaphragm, shaft and butterfly valve.  But the choke is bent and as I said the rubber boot is shot thou it may just be a dust seal so no vac leak.  

I might as well put it back together but feel that I am spinning my wheels.  But maybe the float valve was just bad so I guess it is worth a shot.

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Edited by aviator79
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What you are calling a choke is actually a fuel enrichment circuit.  If that is plugged up or leaking air the bike will be very hard to start as the "choke" won't be enrichinig the air fuel mixture as it needs to.  I would check this very carefully.  This would also be consistent with your comment that it needs starting fluid when cold.

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To amplify on this topic.  A choke sits between the air cleaner and the throttle slide/valve.  As it's name implies, it reduces (chokes off) the air flow through the carb.  This causes increased vacuum on the engine side of the throttle slide/valve.  This causes increased fuel to be drawn through the jets of the carb.  In an effort to improve emissions, the bike makers went to a fuel enrichment circuit rather than a choke.  The fuel enrichment circuit is situated between the throttle valve/slide and the engine.  Rather than restricting air flow through the carb, it opens up an additional fuel path to increase the amount of fuel reaching a cold engine.  If the jets or carb  passage ways in this circuit are plugged up then the fuel cant/wont get there.  If the o-rings on the plunger valve are shot the valve can leak air and defeat the purpose of the enrichment circuit.

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I am trying to make sure the fuel enrichment tube (the external copper tube) is clear but without pulling it off i am having a hard time.

EDIT:

I can stick a wire down nearly the whole ting to the bowl and stick a wire down the tube that is in the bowl and seam clear.  I try to spray carb cleaner but so many holes to plug. Spray air from compressor and do not feel it but IDK.  Will keep on working on it.

Edited by aviator79
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