EC300 losing power + rattle

[kdxtreme]

Have you looked at your stator?

[(F5)]

yes, its kind of round & metally. & underneath I noticed there were a bunch of wires tightly wound round some formers.

[Jakobi]

Originally Posted by (F5)

Thanks guys I'm getting some good alternative info here, hadn't thought about the gas cap & yet have had this problem on roadrace bikes.

Carb vents. . . erm, heck you know I can't remember. I definitely went through the 200 & did them up & out of the way/airbox. Can't remember if I did the 300 fully.

Re the engine lean surge, well, it would be masked, if you are going up a hill you are under load so you won't get a surge, just a big loss of power then the gas would get so low that it would hardly run. That is what made me think carb, but tank venting is an interesting alternative & why these forums are a good sounding board.

ROFL at the stator comment Very descriptive!

Even though the bike will run low on power my first impulse would be to pull the clutch and stop if it was dying out that bad. I'm sure you'd get the tell tale up and down lean surge prior to it dying. I could be wrong. I also think if its under enough load to die without surging that the spark plug should give you a pretty good reading of it being lean.

[(F5)]

Well I wasn't quite sure what he was getting at & if find, being a sarcastic twat is usually the best answer. However on occasion you miss a reasoned reply, but with one liners its a bit miss more than hit.

Yeah it pretty much was always on a hill, but not every hill, in fact there were quite a few in 25-30k loops. If it was occurring on the flat you would get the btchy lean stammers, but I think under load with a big cylinder maybe as the gas runs low in the float bowl it just loses a heap of power & detonates from being lean, -Heck I dunno, that's why I'm asking, I'm used to smaller capacity roadrace bikes.

by the time you pull the clutch & bearing in mind this happens within 20M at a speed of 2nd or 3rd gear I can't see it colouring the plug.

On roadrace bikes you don't get a reading to trust until you are flat out for several seconds then pull the clutch & coast pulling the plug straight away.

Originally Posted by Jakobi

. . my first impulse would be to pull the clutch and stop if it was dying out that bad. . . . .

Actually not much choice other than do just that, bike stammers & you go from 20kph to 2kph in no time & you whip the clutch & front brake to stop rolling back.


I'm getting some good ideas here guys, remember there are no stupid questions, only stupid people asking them.

No wait, hold on, there was a verse there I've got wrong. Work smarter not harder, two bushes in a bird & teach them to fish. Summit like that.

[Jakobi]

Let us know how you get on! I'm all out of ideas for the moment

[(F5)]

Will do. Racing on tarmac this weekend but should get some time during the week to look at the dirtbike & there is a ride at the end of the month. I have a few things to check more than just the carb now.

[(F5)]

well I blew up my race engine so last thing I needed was another bike to fix.

anyhoos I decided to quickly have a looksee at the GG to see if anything was obvious. The cap vent seemed to work, but one could see how it could clog, so I bored 3 more holes in the rubber & one more in the under-cap that retains the stop ball + some trenches so it should be hard to deform & close off airflow.

I then ran the tap into a bucket & it emptied 1/4 tank with no drama. I blocked the gas cap vent & saw it stave off flow & eventually to a trickle. So that isn't surprising.

Vents? well like a good lad I had the top ones into the airbox. Bottom ones weren't split so I cut them, but neither were they blocked.

No water in bowl, well tiny 3mm globule of ooze, but can't see you'd be so unlucky that would be a problem.

Float jet looked fine & took it out to see no restriction or with hose to tank.

Hmm, float height. Read 16mm somewhere, & must research from where to where on Keihins. From gasket face to top of float was also about 16mm. but that is with weight on spring. Hmm, what's this? one float is 2mm out from the other? Well ok I'll straighten that, but not a smoking gun.

Just done a search so will recheck. have to make a 16mm template, my vern isn't wide enough. I'll straighten the float first.

[(F5)]

ok well that was interesting. Definitely a low float height. The needle tag of the float was bent in a queer way so it was sitting at 16mm ('07 PWK) when weight against the spring rather than tilted with spring uncompressed, so either the old owner had the dribbly carb issue or had read the instructions wrong.

I hate that measurement with tilted carb, seems so imprecise, remember it now from my 200.

So I also checked as suggested on that auss website with the carb with no float bowl & gas connected, now shuts off with float seams just before parallel, before it would have been ages before,

Smoking gun? Well well smelly one for sure.

But what is queer is that I haven't had the carb apart since changing the jetting after the first ride & rode it say 8 times since then, but I've only had this issue in last two rides. And I've done some ugly long uphills.

So I'm still a bit concerned. Should find out this weekend unless it rains too much to ride.

Thanks for ideas so far. I also fitted a R/A fuel filter. Had it for months bought on a whim looking for an application & then read people use them on the GG & it found a home.

[(F5)]

Well - complete cure? erm no.

I was supposed to ride last week but there was some unseasonable weather in what is usually our calmest month. I rode yesterday and. . . it was better.

it didn't konk out.

However it did occasionally feel like it was losing power. Sometimes it would rip & sometimes it was soggy, certainly not the lift-wheel-on-command power it usually has. I got to a section that was a little more open & both times I passed this section I held it wide open & the bike refused to rev. Like it was running low on gas.

The plug came out after the first loop (42km) black as soot. I changed plug & the next loop it was dark but not black as before.

I was getting 9-10km/l so it was not chewing through gas or anything.

So the other part of the equation is the pipe. We de-catted it. But for some reason it still makes a vibration noise. I might try my old bashed up pipe & see if the issue goes away. there might be something else in there that somehow closes up the pipe. And then reopens to full power.

Its a long straw idea.

the other one is to swap my mates carb on there, but that is some hassle to go get it & pull it off, try it & then swap it all back again,

[Jakobi]

Got me stumped too.

I very much doubt something in the pipe is restricting and only at certain times. Ignition related perhaps?

I know we both had a chuckle about the post up the top of the page but have you removed the stator cover and had a look to see if any water has been making its way in there? Is it possible that something like that is playing havoc? Maybe its a little loose and is advancing/retarding with vibration just enough to play havoc with the power delivery and fuelling?

If you have someone you can do some part swaps with it'll at least help you to start eliminating more things.