Rev 80 misfire

[jamersby]

Hi guys, I have a 2008 rev 80 which has recently developed a misfire at higher revs, it has a new plug, new HT cap have cleaned out the carb and the stator and checked all wiring but made no difference,we previously had a 2004 rev 80 with the same problem but I sold it with the misfire, the buyer intended to let me know what,when and how he cured it but he never did, so before I go throwing money at coils,cdi's and stators I just wondered if anybody has had this problem and could give me some pointers as to what cures it, is it a common problem with these Rev 80's, any info appreciated.

[dadof2]

Is it an electrical misfire or is it "fourstroking" due to running rich? Turn the fuel off and keep running it - if the misfire dissappears as fuel in carb runs low then it is richness which could be float level, dirty air filter or jetting. If it does not seem to be richness try running the bike in the dark with the flywheel cover off and tank lifted - look for stray sparks paticularly in the HT coil area. Stray sparks are much easier seen in dark than in daylight.

Cheers

[jamersby]

Thanks for your reply dadof2, I don't think it's a petrol problem the spark plug is the right colour, the jets are ok, air filter is recently new and cleaned regular have played around with the air screw and made no difference, but I will try running the engine in the dark and post what I find, Cheers.

[mickmc]

Hi I have the same problem with our beta 80, i've tried alsorts, not been able to fix it, so if you do manage to fix the problem, let me know how you did it

thanks

Mick

[boni_tou_1]

would moving the clip up one notch on the carb needle help if it is rich a high revs ?

just a guess

[jamersby]

I will try anything to get it to run right, I do clean the carb and the jets regular more so after washing down but it used to run fine until recently so haven't touched the slider, I think its more electrical but what part I don't know, is this a common problem with 80,s as my last one did it and Mickmc his is doing the same, will let you know when its sorted. cheers

[stork955]

Gday, if the plug is a good colour and you can find no electrical issues (most likely plug cap etc as mentioned above) have a good look in the exhaust. A buildup of carbon inside can cause some issues, and all 2 strokes need a clean every so often.

Cheers,

Stork.

[jamersby]

Good point Stork, had a new silencer 3 months ago but never checked the front pipe,will put it on the check list cheers.

[jamersby]

Hi guys, back to the misfiring 80, tried the spark in the dark no wandering sparks, took the exhaust off clear as a bell, took the carb off checked and cleaned everything, I took the flywheel off and cleaned the stator and flywheel some dirt but not excessive, I put it all back together it fired up and ran at high revs without missing, ah! great I thought, my lad tested it at a trial yesterday it run great for 2 laps then it started misfiring again but not so bad as before, he finished the trisl with no problem but I still haven't cured it any idea's ?

[mattybeta]

Hi guys, back to the misfiring 80, tried the spark in the dark no wandering sparks, took the exhaust off clear as a bell, took the carb off checked and cleaned everything, I took the flywheel off and cleaned the stator and flywheel some dirt but not excessive, I put it all back together it fired up and ran at high revs without missing, ah! great I thought, my lad tested it at a trial yesterday it run great for 2 laps then it started misfiring again but not so bad as before, he finished the trisl with no problem but I still haven't cured it any idea's ?

can i ask you a few question about the problem

if you let the bike cool off or try a new plug dose it mis fire straight away

was it wet when it starting miss firing (try spraying with wd 40 see if it takes the problem away)

whats it like when on full throttle under load (dose it relate to throttle position or rpm)

is it a miss fire or a loss of power (electric problem or a fuel starvation problem)

hope we can help cheers mark

[jamersby]

Hi Mark,in answer to your questions

I have let the bike cool off and changed the spark plug and it will still misfire at about a third throttle.

When My lad rode the bike the other Sunday at a trial it was wet.

On full throttle under load it seems to be rpm.

It is a misfire.

I have checked the petrol flow which comes through at a good rate, I recently fitted a new in line filter and cleaned out the petrol tank in hope that it would eliminate dirt etc. the air filter is recently new and I clean it regular.

It will rev up fine at half throttle when it starts misfiring, if I clean the carb out and the wipe the stator (when I'm back home)it will rev up fine but only last's for about 40 minutes or so regardless of wet or dry conditions, I'm baffled as to whether it's carb or electrical, should I get the stator rewound and then try it or what? we had a 2004 Rev 80 which had the exact symptons I didn't cure that one either I sold it bought this one and now back to square one.

Cheers Paul.

[mattybeta]

Hi Mark,in answer to your questions

I have let the bike cool off and changed the spark plug and it will still misfire at about a third throttle.

When My lad rode the bike the other Sunday at a trial it was wet.

On full throttle under load it seems to be rpm.

It is a misfire.

I have checked the petrol flow which comes through at a good rate, I recently fitted a new in line filter and cleaned out the petrol tank in hope that it would eliminate dirt etc. the air filter is recently new and I clean it regular.

It will rev up fine at half throttle when it starts misfiring, if I clean the carb out and the wipe the stator (when I'm back home)it will rev up fine but only last's for about 40 minutes or so regardless of wet or dry conditions, I'm baffled as to whether it's carb or electrical, should I get the stator rewound and then try it or what? we had a 2004 Rev 80 which had the exact symptons I didn't cure that one either I sold it bought this one and now back to square one.

Cheers Paul.

seems a strang fault you have paul .

i take there is no one near that you could swap parts with to try such as carb or coil

did you blow the carb out with compressed air ,what about water in fuel ? ,

if its a mis fire would think its electrical rather than fuel which would be more like loss of power and poor running

what about running it with the tank off to see if its tracking out ,or spraying everything with wd40

try re routing coil lead if poss . removing kill switch?

i take it you are no where near the northeast or you could try someparts of our bike

hope you get to the bottom of this , sorry if i am telling things to do that you have tried already

good luck mark

[jamersby]

Hi Mark, it certainly is a strange fault and it's doing my head in, I have tried every thing I can think of with no luck I tend to think it's more electrical but which bit I don't know, the bike is ridable so I will have to put up with it for now. If I get it sorted I will post on this thread so it may help others.

Thanks for your help Paul

[mattybeta]

hi paul been chatting to a freind and he mentioned if i had a misfire on my bike ,because they had a problem with the sators on theirs causing a mis fire at high revs hope this helps

mark

[jamersby]

Hi Mark, I was at Earls Shilton at the weekend where there are alot of Rev 80 riders, after some chat it seems this misfire is quite common, replacing the stator cured the problem I was told.

Reading your post has confirmed it for me, now I know where I am going on this one, thanks for your reply

I will sort this in Jan and post the outcome, cheers Paul