250cc flat spotting

[Woodsy]

Got around 2km from home this morning and the clutch started to slip Badly, had to nurse it home and borrow a car.

I've adjusted it as it says to in my book but its still not right, Revving way to high compared to actual road speed.....

* puts his hands in the air* I GIVE UP!!!

 

[nufnuf]

lol just found this thread josh, dont give up

My very first road bike was one of these and i remember going through some testing times.
Persistance and you will win
The clutch lever needs some freeplay at the bar (some slack in the cable)

If you have the wrong oil in your bike it can make your clutch slip also
( you cannot use friction modified oil)

sounds like crap in the tank

The vaccume control on the petcock works on the natural suction created by the engine running
The same suction sucks air through your air filter
sounds like you might be right about the thing starving itself of fuel
if you havent already, take the tank off the bike, give it a good shake and tip all of the fuel into a bucket then pour it back into the tank
If there is red or black rusty residue in the bucket .....

good luck

 

[Woodsy]

Hey, i tipped the tank out today and did get some black stuff in the bottom of the fuel drum which i made sure did not make its way back into the tank.

I cleaned the Petcock out too.

I have just given the bike a service afew weeks ago using Gulf Western Oil which is Australian Made,they recommend it for my bike but now i'm thinking maybe not.

 

[Guest]

Gulf Western oil? Never heard of it! Mind you I'm no oil expert... but bugger on the clutch slippage, that won't help at all!

I've always used Shell Advance in my 450 and I'm pretty sure it was SX I used to use, but that was too long ago to remember.

When I got oil this time around I got SX4 which is a 15W-50 and still mineral oil but with a synthetic additive. Apparently it's the right stuff but of course I'm in no position to try it at the moment

 

[Woodsy]

Yeah i've gotten in touch with gulf western last night so hopefully should hear back from them today. Pain in the bum!!!!

 

[Guest]

I reckon! The last thing you want when trying to resolve an issue is for a new one to crop up...

 

[Woodsy]

The thing is the Bike sounds REALLY good after i cleaned the tank and the petcock out, the clutch has only been playing up since the oil change, infact the whole thing has come about since the oil change, but i cant blame the oil for the carb probs.

Going to try some Castrol Active 4T 15w 15 and see how that goes... Problem is i have 4L left of the Gulf Western........

 

[Woodsy]

Ok, the oil is fine, the clutch was abit out, i followed my haynes manual which explained it abit better and the clutch is now fine.

However, the bike is still having problems. I took it up the same road and it went well until it bogged down again, although it was on a different part of the road. It seems to be doing it more so under load in higher gears. I shut it down and tried to restart it and it sounded like it was flooding then ran clear...

Originally it was having the running problems at exactly the same point in the road every time, now its abit further along the road.... am i making sense? lol


what adjustments do you think i should make? Pilot in pilot in or out or burning it is also an option.... lol

 

[Guest]

You know, I'm starting to think maybe crud in the tank blocking the fuel tap?

I just remembered many years ago I had something along the lines of this in my first car.

I left my fuel cap on the roof and drove off, so as a temporary measure my dad stuck a plastic bag with a rubber band around it over the filler hole until I could get a replacement cap, but he didn't put a small hole in it.

Anyway, it got sucked into the tank and every time I accelerated it would suck the bag against the fuel pipe, but backing off let it float again, had to take the sender unit off and fish it out with a straightened coat hanger.

 

[Woodsy]

I've already cleaned the tank and fuel tap out though, i've checked the cap too and its venting correctly, i would really like to get my hands on a fuel tap with a prime system on it to see if running it on prime has any effect on it, i would try to bypass the tap by running fuel directly into the carbies from a bottle etc but they bike wont play up unless its got abit of load on it, i might try and richen the mixture and see what happens.. can't hurt.

 

[Guest]

Bugger, I must've missed that.

So, carbs, tank, and fuel tap all clean, is the fuel line being pinched somewhere maybe?

Is this the only place you hit WOT or something? Maybe when the throttle moves that much it pinches the fuel line?

 

[landshark]

What do the plugs look like, how old are they, woodsy?

 

[Woodsy]

Adjusted the air/fuel mix and gave it a little bit more fuel, just to see its effect and it made it worse, it actually bogged so far down i had to pull over because it cut out, was hard to restart and coughed and spluttered for afew revs then came good.

The plugs look good, the end of the plug has a slight coffee colour which is meant to be spot on. However i havent checked them since i made the last change today.

I checked the fuel line and if it was being pinched and it was all good, checked the vacuum on the fueltap and it was good, this road is elevated and is heavy on the throttle, i would say i have it open 3/4 all the way up there because opening it any more has no effect in road speed or revs.

I'm trying to get in contact with the fella who does the o-ring kits but dont get a reply. I'll do the o-rings and absolutely soak the carbs for afew days and see what comes of that, i haven't been able to find any carb cleaner in bulk, only spray cans. I believe in the states they have Pine Sol, which is now discontinued, which is meant to be the same as ajax according to a website i have been on...

 

[landshark]

I'm trying to get in contact with the fella who does the o-ring kits but dont get a reply. I'll do the o-rings and absolutely soak the carbs for afew days and see what comes of that, i haven't been able to find any carb cleaner in bulk, only spray cans. I believe in the states they have Pine Sol, which is now discontinued, which is meant to be the same as ajax according to a website i have been on...

Mix metho and petrol 50/50 and soak the carbs in that for a few days if you can. get a can of carb cleaner as well, to get into the hard to reach areas. if you have a compressor blow them out with that as well.
Robert Barr posted my o-rings from the states and was really great to deal with.
I had an 80 gs250 and after the carbs were done it was a different bike, so once this is all sorted i hope you love the bike.

 

[Woodsy]

cycle o-ring kits? that fella?

I've got a compressor, i love riding the bike and want to get it to 100% so i can go on rides with the Suzuki Katana boys, would it make things easier if i took a video of the problem as it happens? I might be able to mount a camera to the bars.

 

[landshark]

Thats him. he must be busy, cause he provides a great service at a more than reasonable price.
I wouldnt worry about video taping it, just do a really good clean on the carbs. There is a guide on bikecliffs site if you need it, how are the boots?

 

[Woodsy]

The boots are still plyable

 

[Woodsy]

Ok i just put new spark plugs in it and took it for another ride, still get the same problem but this time i opened the choke a little and the problem went away.... so it obviously likes the extra fuel and less air, but if i adjust the air/fuel ratio it still gets the same problem.

I thought maybe just maybe the new plugs could of fixed it, oh well atleast it has new plugs now. I'm going to pull the carbs down, hopefully tonight and soak the hell out of them, i really need the bike for transport but these problems cant be doing it any good. Still waiting to hear about the o-ring kit.

 

[landshark]

Someone with more knowledge than me will hopefully help you soon, but i think the carbs must be dirty, make sure you really get into every nook and cranny soak them completely in metho and petrol for as long as you can. Blow all the sh1t out of them with your compressor.

 

[Woodsy]

not alot of 250 rides on here it seems, i cannot wait to get a bigger bike! I need to go for my P's soon and cant do it on a bike that doesnt run properly.. Lets see how things go over night with the carbs.