This little piggy went Cough Cough Splutter...

Hey,
My lovely '00 pig is sick, and it's getting me down (as you can probably well imagine.) so I've turned to you, piggies anonymous, for help. First, a little of her background: I got my XR 4 years ago, for free (That's a whole story in it's self, but for another time) and she wasn't in a good state. The previous owner had fired her up and gone hell for leather without priming the top end for oil. The result (as you've probably guessed) was that she pretty much ate her own cam, tappets, cam bearings etc. She sat dormant in my shed for over 3 years gathering dust and spiders, until eventually I got the cash together to sort her ills. I opted for the 'Hot Cams' stage 1 rather than stock cam, simply due to it being half the price, I also uncorked her (following all the splendid advice from a certain well loved website) but...(and here lies my problem) the bike will not idle correctly, and feels like the power it's giving is 'fluffy', kinda soft. The idle problem is the biggest deal at the minute.When cold, the bike idles fine, at aprox' the set speed, and very rarely cuts out. (only generally if the throttle is 'blipped'.) (Side note: she does require full choke for cold starts)

When warm, however, the idle wont settle, and climbs to (estimating) about 2500 rpm, if I throttle on and off fast, the revs drop to what they should be. Also, if the revs do drop down to idle, then re applying the throttle can be quite risky, especially in lower gears, as she seems to almost stall, and then gets it together with a sudden surge, leaving me often pondering which end of the bike I'm going to fall off lol (Imagine those guys you see riding bulls in the rodeo, you get the picture)

I don't know if this was occuring prior to me fitting the cam as she was a non runner, but she was definately doing it before I uncorked her, and to exactly the same degree. I've checked for air leaks, I tried removing the foam air filter, I've tried adjusting the pilot screw, I've even tried drinking shedloads of beer and swearing at the top of my voice at her, but to no avail.

If anyone's had similar problems (preferably with successful outcomes) then gimme a shout, or indeed if anyone here possesses a magic wand (working, c/w batteries) that I can wave at her...

Thx

Clean carb!
That means taking it off, remove all & blow compressed air everywhere: on, through, along, wahtever! No carbcleaner can do what this does, pls note.
And immediately after mounting mount a fuel filter too, as no tank stays clean inside.
Also, when in there set the floatlevel to +1 mm (19mm I think) so save you hassles the std carb has when tipped over/leant/dropped. Setting fl-level means turning it upside down whilst you blow into a pipe to see when the needle colses, not turning it 180 deg's and hoping for the best - but surely you know that.
Oh, your idle jet is the 68S izzit?
And you checked the carb2head rubber with a gas-only torch when idling?

See, this is where the headaches start, The carb has been meticulously cleaned, blown thru, licked and fondled, the inlet rubber has been inspected (although not with a gas only torch), not checked float height yet though, so will do that today when I (once again) have the carb off. Fuel filter seems a good tip too, although I did flush out the tank completely only 50 or so miles back.

The pilot is a brand new and very shiny 68s, the main is also new, 175 as prescribed.

One thing I did note when I was uncorking it was that it seemed like one of the previous owners had already made an attempt at it and only done about half the mods recommended, which makes me worry about what else they might have done, i mean, as previously stated, they ran it dry at the top and never thought to stop running it even though it was ticking like a comedy bomb and only managing 35 mph flat out!

When I'm inside it today I'll take a note of all the numbers (needle etc) and put them up later.

Wish me luck lol, I'll report back later

Those rubbers you often don't see anything wrong with, but they've just become hard, then leak. Gas-testing is the answer, failsafe.
The needle's clip - 3rd position from top if I remember correct, but check the net first - is important low down too, so check. Your altitude is prolly 'sea', some hundred meters is 'sea' anyway.
The membrane on the lhs of the carb, under a lil cover - OK? In any case, block the tiny bore of the cover with a drop of epoxy, so that that system (a leaning off the mix on overrunning) won't work anymore.
Now the thickest Q for today, and yes, you may shout ugly things at me for it: the 2 plastic covers/plugs are removed out of the airbox aren't they? Thicker still, all the smog-rubbish (on the rh rad) is gone too, with the vacuum hole in the inlet in the head itself is plugged properly?

No doubt I'll hear your shouting from here

No shouting lol, but yes, the airbox pieces are removed (only one was before i got my hands on it.)

The little diaphragm thingie you discribe did catch my eye, in that the spring in there seems to have been cut, or at least it doesn't terminate in a flat surface, just ends half way thru a coil.

The anti smog smog smog anti thing was never fitted on the uk model i believe, and if it was, it aint there now, all holes plugged with what look to be factory bolts etc.

The needle is a B53E, and is currently sitting on the 4th clip position, it was at the 3rd but i moved it last time i was in there to see if it'd help, needless to say, it didn't improve the situation.

By the way, I've just boiled the kettle, you want a cuppa?

One small detail here: With the bike warm and standing on it's stand, the revs will rise and fall by themselves. ie: idle...idle...2500rpm...2500rpm...idle...idle... Not completely rhythmic, but almost.

I just rebuilt the carb again (set the needle back to slot 3, cleaned and checked drillings etc) and reset the pilot screw to 2 full turns out. Then I adjusted the pilot screw all the way in, and hmmm, the bike didn't stall, so I adjusted it all the way out, and again, the bike didn't stall...

it's now sitting at 1 and a half turns out but again, this did nothing to the actual symptom the bike is displaying. I'm starting to wonder if there might be more to this than just carburation.

Just had a cuppa thanks (burp!)
I'd wave some gas over it right now - and you'll probably find it picking up revs > a leak > new rubber manifold.
If not then I'd take the idle-jet out - complete that is, also the elmulsion tube (you did?) - and check it really thouroughly.
Then, lastly, I'd do the epoxy-droplet thing mentioned above > spring or no spring (but leave it in), end of any interference.
Oh, you did set the floatlevel to 19 now? Turn it upside down whilst blowing through a pipe to see when (at what angle!) the needle closes, and at this position you must get 19mm...... right, now tell me you refuse to blow a carb

Did you check the timing?

Post a picture of the sparkplug

19 mm is the magic number, measured by vernier caliper- check.

Emulsion tube clean as a whistle- check.

Little hole thingie blocked- check.

Timing... I presume from this you mean the cam timing Aurora? If so, yes, it was one of the first things I checked after the rebuild. If, however, you mean ignition timing, then no, I haven't, is it variable on one of these? I haven't played with ignition timing since bikes had points and condensors.

Just for the record, you (BuRP) mentioned a fuel filter earlier, My bike only has about 2 inches between the tap and the carb fuel inlet, and they're at 90 degrees to eachother, meaning my fuel pipe is short and bent (no jokes pls, or I will provide pictures lol) and thus has nowhere I could see to add in a filter.

I take it the throttle cables are well oiled and not binding in any form or manner ?, does seem stange symptoms your having.
I don't think you need a fuel filter our weather is not dusty and the fuel tap strainer is pretty fine mesh I am sure that would catch any tank debris....Burp however gets his fuel out of any old lawn mowers he comes across hence he needs a good filter

"No jokes pls"

Pah, what do you think, that I'm so childish to even think of that?
ME?????
Never!!
Clearly you don't know me yet.
In fact, I think you're very courageous to admit such on an open forum like this!
LOLOL
Buy a fuel filter with 90-deg outlets, they exist and they are very small indeed - or, loop some pipe so as to make it fit.

The ignition timing you can't adjust. Pickup fixed, flywheel ditto, and the black box does the rest, electronic magic - indeed quite different than points & condensor, and you just gave your agegroup away with that remark
As per his habit Mauser makes a very valid remark - the petcock's strainer. No, it won't be the cause of this, but checking it aint a bad idea as they often get 'eaten' by old petrol - and yours was parked for 3 years, not so?

I'm not stumped at all by what you tell us - in fact it convinces me even more that yours is sucking 'false air', that rubber thingy aint closing. Gas* it bru, and surprise yourself.


Edit: * wave a gasburner (off of course, ahem) around that manifold during idling. Yours will pick up revs a LOT I know, all the telltale signs are there. Trust me bru, simple problem.

I'll actually prove it to you:
Idle the bike tonight, in the dark - don't ride or rev it, just let it idle (what it does). Before it is even close to overheating your headers will be glowing hot, red-hot indeed. You will see this happening very quick, wanna bet a beer?

I'll decline the wager of a beer just now, as beer is a precious commodity and is not to be gambled lightly lol. (And I do always lose, always...)

Anyways, @ Mauser: cables are free and oiled, and the problem persists even if you activate the slide lever cam by hand, but again, a good suggestion, I did also check there was nothing fouling the actual slide it's self.

@BuRP: Testing will have to halt for tonight, we in Scotland are afflicted with an age old condition known locally as 'S**t weather' and tonight is a prime example (40 mph westerly and a big cloud with a fair sized hole in it, judging by the amount of water falling out of it sideways!) and having been out for a wee test run already tonight, I'm seriously not inclined to be visiting mother nature again any time soon lol. As far as I can see, the weekend is looking slightly less wet, and thus I may be able to continue then, but for now I'm off to gather 2 of each animal, and see if I can get this blackbird motor into this Ark I'm building...

Thanks for all the tips and hints, and generally good chatter thru the day, I'll check in again once I've had a chance to tinker

G

OK, update on the sick piggy...

Had everything apart again, been through it all with a fine toothed comb, found a couple of small issues (slight kink in the end of the pilot screw, no washer on the carb needle top) remedied these, and now she seems more responsive and generally a little 'cleaner' running. Still not had any joy with the tick over problem, although (before BuRP shouts it again) I still haven't replaced the intake rubber, so no conclusions to be drawn on that just yet.

Now the biggie... This afternoon, whilst travelling to college up the motorway at about 80 mph, said piggy decided to eject it's chain...

Fortunately for me, after the chain flailing about for a couple seconds, it made it's way out of the rear without locking the back wheel or indeed ripping anything serious to bits. The front sprocket cover is minced, and one of it's retaining bolts has been ripped out of the engine casing, but, the clutch arm and casing have survived, and so have I.

So, having just gotten home, bike in van and a**ehole in tatters, I'm off for a long cigarette and a beer! Damn it feels good to be alive!

OK, you can have my beer too
Get XRsOnly's case saver, it bolts to a bigger bolt than the std one does - lots stronger.
But the main thing is, a chain doesn't climb off, it actually cannot.... unless there's something amiss!
Find that bit, and fix it, should help you ride with confidence again.
That also means that you'll have to keep the tension in check, and do note the pun here

PS: Enjoy my beer(s)?

Hey BuRP, I enjoyed your beers a little too much, and am now in a state of perpetual hangover.

Ok, the chain cannot climb off, fair point, what it did was eject it's split link somewhere down the road, thus causing it to come apart and dismount it's self. I've not touched the thing since as I've been busy with other commitments. I have been offered a swap for it, someone seems to want to give me their streetfightered triumph trophy 1200 as a straight swap. (Have to be honest, if it's somewhere close to a half reasonable fighter, I may well be tempted.)

Anyways, I'll write more as it happens.

TTFN Geoff.

Geoff,

Leson Wan: Never ever ride with a removable link in your chain with any bike over 21cc's!!
Leson Too: If you do Murphy will find you!
Leson Tree: Have plenty money if you habitually heed good advice!
Leson For: If you do take advice invest in a DID chain splicing tool, it's like Durex, the best there is, but also unlike Durex because it won't give not even an iota.

As an aside, you're ominously quiet about your idling problem - solved yet?
Getting thirsty ya know.....

Geoff,
You really need to spend more time with your bike and check everything over before riding her @ any speed, you don't know the history of her. I spend literally hours going over my bike cleaning oiling and checking bolts to make sure everythign possible is correct, failure to me is preventable. As Burp mentions and I know it's after the event but split links are a big NO NO your bike puts out 50bhp ish and thats a lot of torque through the wheel and chain etc, staked link is the only way to go but you also need to keep the chain well oiled and tensioned correctly. Not trying to put you down by the way just explaining that these are fantastic ultra relaible bikes but they still need constant attention.
we are having some 1 peice case savers built very soon similar to these...but 1 peice lol.



Not 100% sure if Paul has any 2 piece ones left but give him a shout....

http://www.xr650r.co.uk/

Don't sway the BRP for a streetfighter, get her fixed up and enjoy her

Don't sway the BRP for a streetfighter, get her fixed up and enjoy her

+1

Besides, try to do 1 (one) ride out on it........ and then tell us you still want something else.

OK, couple things to pick up on here:

Firstly, yes, split link = bad idea, but, to somewhat quell the doubting Thomas's out there, I'm a time served and many years experienced mechanic, so with regard to maintenance and knowledge, I do have a fair quota of savvy, and a good idea of how to use it.

Secondly, the idle problem is still present, and shows no signs of wanting to leave. I've tried spray oiling the inlet rubber, gas torching it and wrapping it in tape, to no avail. I'm currently sweet talking one of my mates to get a shot of his carb (standard unit, jetted as per de-cork) Although, I'm starting to wonder if, in some way, the auto lean diaphragm is having something to do with it. The other suggestion that was thrown at me recently was that it may be pooling fuel (or de atomising fuel) off the back of running rich at idle, then drying off once the rpm has risen. it's not something I've ever come across but I'm at the point of clutching at any straws I can get me grubby little fingers on.

Thirdly, I'm travelling about 70 miles a day just now, and doing that kind of mileage (dual carriageway/motorway) is tiresome on the piggy. Dont get me wrong, I love it to bits, but for now the streetfighter option might be a better choice. (The fact it's only half way fightered actually appeals to me more, as not only can I throw in my own creative input, but it also means I might get some wind protection/deflection off the front end.)

Fourthly, I've covered just over 1000 km on the piggy now, and yes, it's fun, but I cant feasably have 2 bikes on the go, and getting any decent trail riding done round here is a feckin nightmare due to the fact that the forest commission and the police take a dim view of it, and are more than happy to confiscate (and crush) your bike if they catch you.

So, that's where I'm at just now, no decisions made just yet, but lots of options on the table.

Well lads what are the chances that i have found the previous owner of my piggy , small eh ?
I have bought Geofs old girl !!! and i still have the mysterious iddle problem , i have contacted him and he is willing to give me helping hand ( i mean helping mind ) to resolve the mystery of " funky iddle " . Wish me good luck . He is a cool guy and willing to help as most of our members .
Only one thing is worrying me and that is the history of the bike , i wonder how badly was she damaged before Geof got her when the camshaft was destroyed ( on a bike with only low miles ) . I hope there is no nasty surprise waiting inside the engine

At least she is back home with us ( her family) .

Decided to continue this thread as the patient is the same and the disease seems to be a mystery .
Today i have flushed and cleaned the complete fuel system , filled her with 98 octane fuell just to test if different fuel affect anything , but no change there , she still runs like a mad cow .
OK then , so far this has been done to the bike -
New rockers , new camshaft ,( done by Geof ), new throttle cables , throttle tube , handlebars ( all to make sure there is nothing obstructing or catching , all moves nice and smooth as before no change in how it runs ) , carburettor completely rebuild ( basicaly just the body was left everything else is new ) jets , gasket set ( seals ) , needle , the lot , also cleanned again just to make sure , result = no change .
New carburetor insulator and checked for vacuum leaks , no leaks as far as i can tell , = no change to the funky iddle .
Tryed different air filter today just for the fun = no change
I am running out of ideas now , there is not much left to try but i am not the type to give up .
i would like to find someone closer to me with XR to try to swap the carburettors just to be sure or rule out that
its not the carb ( possible crack on the carb body somewhere ? ) before moving inside the engine , the valves and the timing chain are the last two things left to change if it still runs like mad cow after this then i am out of my mechanical knowledge and this truly is a strange thing , i have never seen engine behaving like this before .
Just wish that i find the problem and i would be the happyest person under the sun , instead of wasting money on stuff which is not even broken , wish me luck please i need it .

Did your check the timing?

Exhaust leaks?

Did you swap in a new electronic ignition module?

Good luck sounds exactly the same as what my pig dose hope you come up with the answer defiantly keep my eyes on this thread.