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Beta 80 bogging down

Posted: Tue May 15, 2018 10:20 pm
by Backintoit
I purchased a new beta 80 for my son to learn how to ride trials in May 2015 . He has ridden it 8-10 times without any troubles & a few weeks ago he went to ride in his first trial for the year & in the first section went around a tree & went to accelerate & the power was bogging down & konked out.For the next hour it would start, work normally for a while & once in 3rd or 4th gear reving it out it would bog down like it was starving for fuel.It had plenty of fuel & the fuel was on properly. I changed the spark plug & the same thing happened. I have since taken the Carby off washed it out & blew out all the jets, cleaned the air cleaner & still bogging down. I took the silencer off the exhaust pipe because I thought it might be clogged up with oil , still bogging down.I use125ml of synthetics 2 stroke oil to 10 liters of 95 octane unleaded .
What I can’t understand is why all of a sudden it starts bogging down . I haven’t changed any carby settings from new. Has any one else had the same problem or know how to fix it ?

Re: Beta 80 bogging down

Posted: Wed May 16, 2018 8:19 am
by motocentral
I had a similar problem with a Sherco 50 & it ended up being too lean a fuel mixture. the engine was getting too hot & the bike just stopping until it cooled down. The Beta 80 specs recommend 1.5% oil/fuel mix which is 150ml oil to 10 litres. maybe try mixing up a tank of fuel at that mix which is more oil than you are currently running & see if it still does it?

Re: Beta 80 bogging down

Posted: Wed Jun 06, 2018 8:01 am
by Backintoit
Thanks for your suggestion. I mixed fuel at 1.5%
, tried it & it’s bogging down still under load. I have taken the stator off & checked the resistance . It reads 302 ohm & the manufacturer says it should be 320 ohm.allowing for some tolerance that difference shouldn’t make a difference, should it ? I also took the carby off washed & blew it out again & it worked perfectly. A few hours later jumped on it again & it started bogging down again.any other suggestions on what it could be ?

Re: Beta 80 bogging down

Posted: Wed Jun 06, 2018 9:47 am
by Jools
Does it bog down only when under load?
Cold and/or hot?
Check your fuel tank breather isn't blocked and that the fuel taps and lines are clear.
The other thing is that he symptom sounds similar to an ignition condenser breaking down,
but I've no idea about the ignition system on the Beta.

Re: Beta 80 bogging down

Posted: Wed Jun 06, 2018 5:28 pm
by Davedeece
Have you tried another plug?

Re: Beta 80 bogging down

Posted: Wed Jun 06, 2018 6:45 pm
by Jools
Yes Dave.

Re: Beta 80 bogging down

Posted: Wed Jun 06, 2018 8:01 pm
by David Lahey
I would say that the pilot jet still has some gooey fuel residue inside it, making the jet passage too small. It's a common problem with modern petrol if you leave petrol in the float bowl and let it evaporate off.
Compressed air won't always remove it

Re: Beta 80 bogging down

Posted: Thu Jun 07, 2018 9:01 am
by TRIALTECH
possibly related but your symptoms are little different. Generally we usually start diagnostics by Isolating the lanyard and/or proprietary kill switch before going any further (you may have already).
Check the cleanliness of the earth point under the tank near the steering head. Had a couple of Beta 80s that had high resistance there causing a few issues.
Feel free to call us if you require any help..
Denis

Re: Beta 80 bogging down

Posted: Sun Jun 10, 2018 8:07 pm
by Backintoit
Thank you all for your input.
I have fixed the problem.
I took the carby off again & removed all the jets.I ran a thin fuse wire thru all of them & one of them was partially blocked which didn’t dislodge with washing in fresh petrol or blowing compressed air through.
The bike works perfectly now but had me baffled for a few weeks, glad it was something simple & inexpensive!
The young fella’s cheering & cant wait to ride again,tomorrow !

Re: Beta 80 bogging down

Posted: Mon Jun 11, 2018 9:41 pm
by outforfun
Good to hear that you fixed it and the young fellow is champing at the bit to get out and go riding