over oiled 2 smoke dead :(

[skatefreak]

Hey all,
so i swapped the old engine back in (honda NSR125 RY) and when it was in i started it first compression and ran great but was not smoking atall so in a panic i pulled the oil pump cable to full.
Sure enough it started to smoke after a few mins and all was good.
Stopped the engine and finnished putting her back together.

The i tryed to get her going again, lots and lots of smoke each time i tried to run the bike, it would struggle but i figued it would burn it off, eventually it seemed to give up.

I have had the carb appart and cleaned the jets incase some oil got in there and blocked them, put fuel directly into the engine to try flush out any oil in there but the bike doesnt even fire up now.

Really really winding me up, there is fuel (wet plug, put some down the spark plug hole) and deffinatly a spark which doesnt half smarts (bump starting it so went by feel, then checked the colour, a healthy blue) and i know the final element is air but not sure how i could check that (everything seems free flowing).

The bike doesnt even seem to try firing anymore. I know it sounds rediculous as all the elements *seem* to be there so what am i missing here

Any thoughts would be much appreciated.

Best regards

-Jvr

[at106]

First i would make sure the air filter foam is dry, that will let the most air possible get to the engine.

Then remove the spark plug and clean it and dry it. With the spark plug out turn the engine over a few times to try and get extra fuel and oil out of the engine. Then put the plug back in and it should fire up!

[skatefreak]

removing the air filter is one step i havnt tried but i have bumped this bike so many times in the past 48 hours the chain has streched a little

At first it would run but really rough, i have flushed the bottom end with plenty of fuel and now it just doesnt run.

I have a horrid feeling its an ignition bug as i smell fuel but i know there is a spark.

Could it just be that there is to much oil in the fuel still?

Best regards

-Jvr

[serlant]

fuel fuel fuel, unlikely but flooded it?
____________________
04 CBR1000RR, 1995 Husqvarna TE410, 1998 VTR1000(Sold), 1990 XJ600(sold), 1996 KH125(dead and sold)

[skatefreak]

Spun it over quiet a bit without the plug in and it turns over okay...

Anyone think exessive amounts of oil could have caused the compression to foul the head gasket? Radiator is slightly down since i put the engine in which could be down to 1, air pocket filling once i started it or 2, fouled head gasket

Have topped it up, going to push it around some more and see what happens ...

-Jvr

[SuzukiTom]

have you ever actually put a tester on and checked the compression reading?

[skatefreak]

hey,
dont have a compression tested but this engine ran like a champ before the engine swap and after i put the engine back in it started up first compression so i wouldnt have thought it would be an issue.
That being said i dont have a compression tester nor do i know anyone local who does
May have to make a trip to the bike shop, get a new plug and see about a compression tester i guess...

Update on the engine, pushing it halfway down the road in first gear and it fires a couple of times on and off so at least its now trying.

I have cleaned the jets, not fiddled with anything else so a little unsure as to what it could be now.
i havnt played with the mixture appart from messing with the oil pump which is now at factory settings...

Am going to have a sit down, mighty knackered

Best regards

-Jvr

[SuzukiTom]

hmm, worth seeing if you can beg borrow or steal to try it out. just to make sure your not flogging a dead horse.

anyway might be worth popping the exhaust header off and having a proper look in there to make sure its not totally gunged up!

do you skate street or park?

[MarJay]

[skatefreak]

Heh,
Started out park on a board, after a while ended up street on a board and park on skates, eventually became consumed by skates both park and street for 5+ years.... then i got old 'sighs'.
Dont wanna become that old guy hanging down the skate park though so yeah...

Might have to make a trip to town to get a compression tester and a new spark plug.

Cleaning off the plug she'll fire a little more and then die.

Back to bump, plug out, clean, in, bump...

Getting a little better though...

Cheers

-Jvr

[SuzukiTom]

it could well be just super gunged up in there thinking about it

[skatefreak]

Yep,
I think you're spot on there but there a supprise issue now
Got the engine running, revved up, sh*tloads of smoke (crankcase must have been saturated), but yes.

So engine gets going and running okay ish, suddenly cuts out and i think okay, push back and lift the tank to pull out the plug then i smell petrol... lots of it, and then hear it and its pissing out under the bike from the float bowl drain (theres a breather in there).

Either the float is stuck/inlet valve has something holding it open or the float valve level has spontaniously somewhere between starting and it dieing.... (impossible i would have thought).

Confusing, carb out time

-Jvr

[0l0dom0l0]

[skatefreak]

I meant the needle valve operated by the float (float needle?).

The engine will run for a short while now but is pretty rough, wont pull and stops after 15-20 seconds, spark plug out, clean and it happens again consistannty so i'm off to find a new plug....

Its still smoking but i'd be supprised if it hasnt cleared itself out yet...

Mixture issue?
Only think i've messed with is the oil pump which is back where it was...

confused and frustrated again....

-Jvr

[skatefreak]

bought a compression tester, the first 3 tries told me all i needed to know...
110psi exactly each and every time... Its a little down on the reccomended 125+ but it should still have some go in it...

I would throw on the spare top end but i'm not sure what size the piston/rings are and if i swap the cylinder i dont have a fresh gasket

Wondering if it's worth having a bash at swapping the top end, using the old gasket for now?

-Jvr

[Kickstart]

Hi

If you are going to the effort of putting the top end on then I would put a new piston and rings in at the same time.

Recommended is 142+/- 28 I think, so 110 is pretty low.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[skatefreak]

yeah,
I wont know the piston size untill i get the top end off though...
I can see a rebuild soon would be a good Great idea but I still dont think its the underlying problem here...

The behaviour is now this:
Clean oil/fuel off plug,
plug in,
bump (it runs for 10-15 seconds without fail at this point and then dies)
Repeat cycle.

Regardless of how long its left, without wiping the plug it wont start but once wiped it will still die again. The plug comes out wet with what appears to be a reasonable amount of oil over its surface...

I've been doing this for the past 15-20 mins whilst waiting to pick up a new standard plug, i've been trying both an NGK and iridium (likes the iridium a lot more) to be sure all the oil is out of the system. Its smoking a little less now (a little closer to normal) but keeps dieing...

Seems like the classic symptoms of fuel starvation but i cant see how this can be as I have not changed anything in the carb (asside cleaning it out etc).

Its a lot better now than this morning, its more responsive and doesnt just moan at throttle inputs without accelerating but its still dieing.

Cup of coffee and i'll get on my push bike to pick up the new standard NGK plug.

Best regards

-Jvr

Ps, a rebuild will be on the books for the near future, and a new(weemoto knockoff)/second hand starter as mines beyond repairing

[andy_uk]

Couple of suggestions...
1) When you checked the compression, did you have the throttle fully open? (the reading will be truer if you did)
2) Seeing as the plug's still getting gunked up...make sure you've got the right plug (NGK BR9ECS).
____________________
Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...

[skatefreak]

Hey,
Yeah, i had the throttle open.
Got the bike running, new spark plug made all the difference but it seems the con rod could be bent, there is some heavy vibration and the bike has lost a lot of power.

Will have a shot at a squish test and see how it pans out

Thanks for all the input guys.

Best regards

-Jvr

[P.]

Ever thought the compression is low as the rings could be screwed... and its cutting out because it physically cant stay alive with such low compression. Simply popping the head and barrel off to look would be ideal

Friends RS became a slag to start after about 115psi... after a few more days it started shooting down and got to about 100 and needed a rebuild before it would fire up at all.

[Robby]

Why do you keep bumping it. Are you trying to identify a running issue while you know it has a knackered battery?

Sticking floats happen, a firm tap with the back of a screwdriver normally sorts them out.

[devojunior]

whilst at halfrauds get a new spark plug and i bet it fires straight away if not il eat my hat .

good luck.


Adam.

[Germ]

[Livefast123]

Check your fuel filler cap vent isn't blocked and causing a vacuum, my NSR had a simular problem to this and it turned out to a be a combination of fuel flap vent blocked and inline fuel filter causing fuel starvation.

However with 110 psi I would be doing a top end rebuild first before trying to diagnose any other issues. That is really low and the engine probably can't run properly. Get a cheap 54mm piston kit from ebay and go from there, think it cost me around £24, bike was running lovely with it when David Silver would only sell a barrel and piston at £160. How long it would last I don't know as I sold it.
____________________
Current ride - Yamaha MT-07

[skatefreak]

No hat eating will be required,
A fresh sparky sorted it out and the engine is 'running' well asside further issues such as a suspected bent con rod.
I'll start a new thread about that but in conclusion it was just a cr@p load of oil in the crank case that buggered two plugs (one iridium ).
Lesson learnt = never underestimate the good a new plug can do for a two stroke!

Cheers for the input everyone and best regards

-
Jvr