Atc185s running rich?

[David2882]

`I bought a 185s probably 5 years ago.. The bike was in great shape when i bought it, was told it hadn't been run in a few years.. I got the bike running pretty quick but started fouling plugs right away...I was in a hurry to get the bike running to take it on a trip i was going on so I swapped in another 185 engine I knew ran well in a differant wheeler thinking i possibly had a low compression issue.(I believe i swapped carbs as well)... I put the other engine in and had the same problem, engine fouled the sparkplug after the bike warmed up and ran for a little bit.. Knowing the 2nd motor was a good runner this lead me to believe i had a jetting issue causing me to run rich.. unfortunately I left town and the bike sat...outside... until now. I have had a few of these bikes i have resurrected over the years and I have never had to do anything with these carbs other then spray them out with carb cleaner and compressed air.. so looking for my jetting issue i noticed that the airbox lidhas a couple holes drilled in it for more air flow also the exhaust doesnt appear to be stock to me..I thought if anything this should give me more air flow and cause the motor to run lean, but im not just learning about jetting..

what do you guys think?? any help would be appreciated..

180631

180632

[David2882]

just checked compression on engine #2 currently in the bike... got a low reading of 90 psi, put a squirt of oil in the cylinder and got a reading of 125.. this indicates worn rings and the cause of my low compression is not in the valves correct?? going to go check the compression in the original engine... any reason i cant do this on the bench before i install the engine in my bike?

[David2882]

....well sorry guys.. feeling like a real dummy now... this was my first attempt at a compression test and im afraid that I may not have had all my connections as tight as they should have been... performed the test again and got a consistant 140 psi 5 times in a row.... so it looks like im going to dive into the carburetor to attempt to find out why this engine is fouling plugs... anyone else had this problem? anything to check first? thanks

[kb0nly]

Hmm, the fact the airbox has been messed with tells me its probably had an issue for a while and someone else tried to fix it with more air. I suspect the exhaust is creating too much of a restriction which is causing it to run rich. Could try pulling the exhaust and running it on a straight pipe for a while to test that. 140 psi sounds good.

[David2882]

Thanks for the tip that makes sense.. I'll pull the exhaust off and see what that looks like..

[David2882]

Anybody on here have a muffler for a 185 that they will make me a good deal on??

[David2882]

found a stock 185/200 muffler here in town I am going to try.. Its a little rough but it should work just fine for now.. maybe if I ever get this bike running right I will buy a nice aftermarket one off of ebay.... Going to clean out the carb while I am waiting for my new throttle cable to come in...

[David2882]

Got the new throttle cable in the mail today, put the keihin PD35A carb on, put the correct DR8ES-L spark plug in, put a stock exhaust on(it is leaking a little). Bike fired up immediately and I revved it up for awhile in the shop. pulled the plug and its looking pretty black again. I double checked my compression and I am still getting 130-140psi. Any ideas as to why I am still fouling plugs?? :wondering There is not currently an airfilter on the bike as I am waiting for my Moose filter to come in..

[barnett468]

float level might be high or float might noit be shutting off gas.

connect 10" long piece of clear tube to carb bowl drain.

hold open end even with top of carb.

open tank fuel and carb drain valve.

fuel level should be at or 1/8" below bottom of carb bady.

set floats if necessary.

once gas level is will it start easily with no choke and around 1./4 throttle?

if so idle jet is too large.

if idle circuit is ok but loads up when throttle is opened main jet is likely too large. install one 4 sizes smaller.

what is carb?

what is main jet size?

[David2882]

carb is keihin pd35a ... If the float was high wouldn't I be dumping gas out the overflow.?

[David2882]

havent had a chance to tear in to the carb yet but i did notice the needle jet clip was in the 3rd groove not the 2nd like the manual suggests.. Im not positive exactly what effect this has on jetting

[yaegerb]

is your pilot screw out 2 turns and if so is the throttle crisp when you blip it and does it return to idle immediately? The needle will only effect 1/2 - 3/4 throttle, so if you are only idling it in the garage and the plug is sooty then it would either be from too large a pilot jet or oil getting past your rings. The lowest acceptable compression on that motor is 156 +/- 14, so that would put you at 142 as your minimum acceptable level of compression. If you are running between 130-140 then you may need to replace the rings.

[MNhondaguy]

Try and get a new air box lid, leaky exhaust should be fine, get the engine in the bike and run it around, not just revving in the shop.

[barnett468]

carb is keihin pd35a ... If the float was high wouldn't I be dumping gas out the overflow.?not if it was just a bit high.



i did notice the needle jet clip was in the 3rd groove not the 2nd like the manual suggests.. Im not positive exactly what effect this has on jettingthis is not your prob. it is a very fine tuning adjustment with minor effects.

needle on top = lean, needle on bottom = richer.

[David2882]

The lowest acceptable compression on that motor is 156 +/- 14, so that would put you at 142 as your minimum acceptable level of compression. If you are running between 130-140 then you may need to replace the rings.

I also read this in the service manual... I thought 130-140 was still decent and shouldnt cause the plug to immediately turn black! It is wet and looks more like gas to me? I just realized I should probably change the oil in this engine done think its been done... I have 3 other 185 motors and would like to make sure that this one is too tired before I start swapping them in to check compression...

[David2882]

pulled the carb apart tonight looks pretty clean for the most part... I do have a 95 main jet.. I checked my Pilot screw and it was only out about 1.25 turns, also it does not have a spring on it like the diagram in my shop manual.. I attached a picture of what it looked like when I pulled it out.. Didnt get a chance to set my float height as my digital micrometer was out of batteries.. Will try and get that done tomorrow..

Thanks for all the help so far guys..

180954

[David2882]

I gave up fighting this thing and bought a replacement carb from Zoom Zoom Parts. $26.00 and free shipping.. Can anyone tell me what adjustments these things need out of the box? I believe some people have said all they needed was to set the pilot screw to factory specs? ...

Thanks..

[webbch]

If missing the spring, I'm guessing it was also missing the washer and oring as well. If missing those items, then the recommended settings for the pilot screw are meaningless IMO. On engines I've had missing those items, the pilot screw was normally turned in much further in order to compensate (not that I'm recommending it). Thankfully, most carb kits come with those items, so it's easily remedied.