BIKE F*CKED- WENT INTO REVERSE!!!!!

[stirlinggaz]

Hi all,
the bike i bought only yesterday is f*cked.
arrived yesterday at 10am & off i went to work at 12.
stopping to put a little petrol in it.was gonna run it empty to see how far i would get out of a tank.
went to work & back seemed ok, bit hesitant at WOT, so took it easy, never really went above 8000rpm.
done only 30 miles yesterday.
today when it started, the revs shot up to 9000rpm, so i immediately shut it off.
put it onto Reserve & re-started it-no problem.
went & got petrol & parked it up till the rain went off.
went to go for a wee run, when the rain went off......
got 2 miles & when i got to standstill at a roundabout & tried to pull away, it seemed very gutless.
was only doing 20mph through the roundabout & @5000rpm,
wouldnt go any higher.
strange i thought.....
dropped it down a gear & revved a bit higher, but struggling to get over 30mph!
(by this time im off the roundabout & onto the dual carriageway)
felt the heat at my right leg & watched the temp guage go slowly but steadily up.
so i pulled over at the first suitable location, when the temp guage was at almost halfway.
by this time the exhaust was very hot & smoking very slightly.
(but it is a 2 stroke)
i let it cool down, whilst texting the previous owner, who was as concerned as i was....
it re-started after about a dozen kicks!
but when i pulled away it cut out.
it then restarted but when i let out the clutch-it started going backwards!!!
im presuming this is a sign of something catastrophic?
like new engine time? (not worth doing as the bikes nearly 25yrs old)
or at the very least full re-build?
anyone?
cheers,
GAZ
ps-thanks to the 2 guys, (one named Rab,cant remember the actual drivers name, sorry, ) who stopped & gave me a lift home with the bike on their trailer.

[MarJay]

Its possible to run a lot of two strokes backwards. It probably won't have done much harm.

On reading your description, it sounds like you've made the engine run lean by running it out of fuel and trying to start it again. This will make it run hot.

I suspect you haven't done much damage if any, but next time make sure you fill the bike up!
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[ms51ves3]

The reverse thing is very strange but it seems that as the spark plug sparked it made the engine run in reverse. As Marjay said, you can run them in reverse. Truslack did it with his RS50 at a meet, unfortunately I wasn't there

It also sounds like when you flicked it on reserve you got some crap sucked into your carb giving you the sluggishness at low revs.

Not sure about the overheating issue though. Just check the obvious stuff like coolant.

[Flip]

How do you stop them running backwards?

[dgo1212]

Had the same problem on a very old Beta trials bike i had,was something to do with a "timing plate" slipping which would explain the overheating aswell,can't tell you how to fix it as i didn't do it myself as i know feck all about bike engines but the symptoms were the same

Also didn't do any damage was just a case of having the plate re-set

[ms51ves3]

[bikersupermot...]

iv had this overheating thing on a suzuki ts50 yonks ago ... there was an air leak where the carb is attached to the engine ... the mixture was weak coz of the extra air going in.

caused the engine to lose power and misfire/backfire on full throttle ... but i was a long way from home an had to ride at full throttle misfiring all the way for about 12 miles ... it started to get dark - late at night .... i felt my left leg getting hot - looked down an saw the exhaust was glowing red hot all the way from engine to the beginning of the tail pipe. then looked behind and red sparks were coming out the exhaust!

the misfiring/backfiring was melting something but i just kept going coz didnt wanna conk out in the dark. just made it home!

next day bike started again fine but wudnt rev to the red line any longer!. so dunno wot happened to the engine!.

so am thinking uv got the weak mixture causing the overheating on yrs. adjust yr mixture - even try running with the choke out to see if its any better.
____________________
tinybikes

[MarJay]

Yes, upon reading some of the posts above it does sound like it could be a worn thing inside your alternator. Its the thing (maybe its called the timing plate but I thought it was a woodruff key...) that governs your ignition timing. If it wears then your timing will be out and that may have precipitated the running in reverse.

What ever you do, DO NOT adjust anything on your carbs. You are likely to compound the problem with a poor carb setup.

I'm afraid I have no idea how you can diagnose the problem without pulling off the alternator, so I suggest you invest in a puller of the right type. Good luck.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Ariel Badger]

If the spark is over advanced a smoker can run bacwards. Just check the timing and as said above bump her forwards to correct.
BTW, what bike is it?
I bet the points are on a plate with a couple of slots in it to allow adjustment by loosing off screws. It may be the timing is out or it could be you are not riding her hard enough, strokers are meant to rev to perform.
____________________
Bikers make great organ donors, get 115 on your licence today.

[The View Askew]

I remember something about reed valves being able to open both ways, not sure though, maybe its worth checking that out.

reed valves are a factor in running a 2 stroke backwards I'm positive of it.
____________________
"Do what you always did, get what you always got"

[Flip]

No, no, no what you want to do is turn the bike upside down...

[Phoenix]

Yes they a factor in 2-strokes running in reverse because the valve operation is activated by the cylinder vacuum, so no matter which way the crank is rotating it works the same, won't do the gearbox much good I imagine though running in reverse for any period of time, opposite wear etc, not that you would.

We had a some 2 strokes in work at my old place and for a laugh we bumped a couple backwards and had a backwards race up and down the carpark, it was very difficult...

[stirlinggaz]

Hi all,
thanks for the replies.
for those who are curious, its a Honda MTX 125 but has the 200cc engine fitted (with ATAC valve fitted)
looking at the ATAC (how it works is still beyond me, even though Keith gave me a brief decsription of how it worked some time ago, lol)
it like a push rod type thing, how to explain....
there is a rod (i just bled the brakes on my suzuki with a big syringe & if you picture a syringe, the bit you pull out of the barrel, it looks like that from the outside)
this rod thing can be pushed/pulled in & out by hand.
it is coated in oil & looks to me like it should spring in & out, as there is a spring attached but it looks like it has dis-lodged itself from somewhere.
as for the carb, its looks like the correct carb for the engine. (KEIHIN PE 65 is whats stamped on the carb, looks like about 26/27mm, i checked a few foreign off road bike sites)
the plug is new, installed by the previous owner.
BR8ES, though i would have thought it should have the BR9ES.
plug look a bit oily but nothing major. (i hope)
i have taken the carb off & given it a clean. (something i have done a few times now, lol. -but not on this bike)
as for the timing, this is where i get lost.
i dont have a fly-wheel puller & dont know how to check the woodruff key.
i have resistance at the kickstarter as per normal & its sparking.
fuel is getting to the carb.
being a kick start only, im not not sure about the compression.
i have a compression tester & will attempt to test it when i put the carb back on.
thanks again & i will keep you all posted.
part of me still thinks its gonna need the head off.... & a new piston..new rings...new cylinder, doom, doom & more gloom, lol
cheers,
GAZ
ps-now going to study the workshop manual which i have just downloaded.

[dgo1212]

To check the woodruff key you can slacken the flywheel nut and tighten it back up fingertight,grab the flywheel and try turning it,if it turns freely on the crank the woodruff keys gone,however i'm thinkng along the same lines as Ariel and going for the timing being out,if you can get the flywheel off without damaging it and see if the plate has come loose and moved(see if there are any round marks on the adjustment slots where the bolts could have been tightened before) and if so try lining it back up to them

[Beamexican]

Hi there don't know if this is of any help but i have an mtx and have heard of a few needing knew fly wheels as the old ones were knackered, not sure in what context they broke though.
Rick

[stinkwheel]

Just to agree with others. A 2-stroke running backwards and way too hot is a classic symptom of too far advanced ignition timing.

If it is a CDI, either the flywheel or the pickup coil have moved in relation to one another somehow.

If it's points, could be as simple as the points needing to be adjusted.

Honda flywheel puller, Part number: 07933-0010000 is what you want, comes in at around £10 from David Silvers. It really isn't worth fannying about without one, turns a hard job into a piece of piss. They fit loads of other bikes too.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[binge]

[stirlinggaz]

hi,
just to update this...prepare for long post....
when it re-started & went into reverse mode, i panicked & hit the kill switch & i only moved back about 6 inches.
i then managed to get it back into neutral & it re-started once more, then cut out.
since then it has not been started.simply because it refuses to!
heres what i have done so far....
carb off, cleaned & re-fitted. im using my home made, remote fuel tank at present (frankfurter jar,with a lenth of fuel hose sealed into lid. ) carbs getting fuel & im getting a spark.
compression seems very low at around 85psi but its kick start only, so i dont know how accurate/reliable that is. (though i did kick it over 3 or 4 times, each time getting the same reading)
a few things i came across that worried me...
idle adjuster wound all the way in..tight.
127 main jet (would have thought that it would have been bigger )
carb to air box trumpet not seated correctly. it wasnt tightly connected. (the groove on the neck of the rubber trumpet wasnt seated all the way round, leaving a small gap at the join between trumpet & airbox)
there are signs of previous overheating. the top of the airbox is melted a bit,where the exhaust passes it.
also the right side panel that covers that part of the exhaust, has melted very slightly.
surely the exhaust shouldnt get that hot?
this is where i felt the heat, just prior to me pulling up.
when i removed the engine casing, a ring shaped piece of sealant fell out. approx the size of the flywheel nut.
throttle cable incorrectly adjusted. the carb slide wasnt closing when throttle was closed .
i have now loosened it off & the slide will NOW now clunk down, but its only springing back 3/4 of the way down.
i have to physically push the throttle grip back to get the slide to close completely.
the ATAC thing is definately not working as it should, there is a spring & bracket type thing attaching the 2 moving parts. (one part is a rod pointing upwards that moves round, the other part is the bit i mentioned before, it goes in & out of the side of the cylinder).
this "connecting bracket" looks like its not working, as it has a spring but nothing is springing backwards or forwards.
i can reach down & pull the thing in & out though
& it STILL wont start.so what next?
i will order the puller in the morning, thanks for the part number Stinkwheel.
sorry for such long posts. , im trying to put in as much detail as possible, in the hope that someone can tell me what hapened & what i can do to rectify it.
in the faint hope that its something that can be easily fixed, without having to remove the head, to find a trashed piston & a thoroughly scored barrell.
any advice welcome (apart from "scrap it",lol)
cheers,
GAZ

[Kickstart]

Hi

The MBX125 is CDI ignition and 90% sure the MTX125 / 200 are as well. Unfortunatly I can't find my MBX / MTX Haynes manual. Could be that the flywheel has moved a bit. However the kickstart only turns the engine one way, so for it to run backwards it must have kicked back.

All the best

Keith
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[bikersupermot...]

hey ... similar thing happened to my dtx today ... was riding into glasgow, just left my place, accelarating down a hill when i heard a loudish click sound. followed by a loss of power ... lucky was goin down hill an managed to keep goin with throttle pinned.

got to bottom of hill an with throttle pinned it took ages for revs to pick up ... once they were up i managed to pull away but loads misfiring and backfiring ... was originally on my way to bike garage to hav the power valve looked at! an now this new prob...

managed to somehow ride into city centre with bike spluttering and backfiring all the way ... an car drivers an pedestrians all bewildered by the noise an starin at me ... but finally just after i pulled away from traffic lights at glasgow green it gave up an died.

so managed to push it in the sun an in my leathers sweating ... to the garage ... looks like it cud be ignition coil/cdi unit/timing sensor on the flywheel. hopefully know by fri wots up with it.
____________________
tinybikes

[rottie007]

well I can tell you I feel bloody awful reading this mate, im grateful for you keeping me up to date with the progress with it via text and as I said I will do what I can to help you get it sorted..

(it was me who sold it to him)

in the time I owned the bike I never disturbed the flywheel, yes I did change the plug and when I first used the bike that join in the exhaust pipe had been done with a bit of rubber pipe which had split and thats what caused the melt on the airbox, but as it was the other side of the foam I didnt worry about it, (thats why the back box pipe had been extended an inch so the rubber could be done away with.

I'm still waiting on Daz to see if he can get me a motor from japan, cause if so its an easy fix for you mate and provided it isnt bank of england dollar I should be able to sort it.. this bike was my first experience of 2-stroke riding and to be honest after this I wont be trying them again..

[frazer1981]

I have had the same problem with my MTX125 as well and suspect that something behind the flywheel is lose or broken. When you said that you had notied some overheating near the airbox, i have had the same problem with mine, but there should be a small curved plate on one side of the airbox assembley to stop this. Does the ATAC thingy actually make much difference to the power of the bike as i have a complete ATAC fitted 125 engine in my garage that i was going to put in, once i fixed 2nd gear in it.
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1st bike - chunlan starway 50QF4 (SOLD) 2nd bike - 92 Honda mtx125RW-L ( In my garage awaiting some TLC)
05 Honda xl125v Varadero stolen and recovered but now a write off!
07 Hyosung GTR125R

[Kickstart]

[stirlinggaz]

hi, all,
another wee update...
local mechanic offered to pick it up on the way past & have a quick look at it.
seems its in a bit of a state.....
ignoring the top end problems, which i can sort no problem. (hopefully)
what worries me is everyone saying the same 2 things.
flywheel & timing.
2 things i know feck all about. (all i know is its CDI).
anyway the bikes now back at mine, but where do i start?
i have ordered a hard copy of workshop manual (couldnt find a version to download, in English anyway, lol)
so if anyone wants a copy, get posting with advice & i'll photocopy it at work. (if your really helful i'll laminate it, lol)
also ordered the flywheel puller & top end gaasket from david silver.
the nut in the centre of the flywheel worries me.
looks like instant gasket behind it.. & when i removed the cover a piece of black sealant/instant gasket type stuff fell out, exactly the same size as the flywheel nut.
i have removed the nut with my little windy gun.
oh & the ATAC thing had a rubber cover on it, so i couldnt see it moving, but before it died, it would get a boost of power around 7500rpm, which suggests the ATAC powervalve thingy WAS working, though the little spring clip thing is now loose, so the thing wont move unless i push/pull it by hand.
what next?
cheers,
GAZ

[Kickstart]

Hi

What can happen is the woodruff key shears off and allows the flywheel to move slowly. Could be that someone has had this in the past and attempted to use the sealant to try and stop it moving (if so just be glad they didn't use loctite on the taper).

As to the boost at 7k or so, a power valve generally reduces that kind of step in the power delivery. Could be the system is sticking with the chamber closed (or it could be a non standard exhaust).

All the best

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