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Beta Evo 2013 Engine Rattle


skyline1
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Hi All

I know this title has been asked before but not quite what I have on my bike.

the bike is fine on tickover & fine reving out of gear & fine just riding about but when I ride up long steep banks or put the engine under allot of strain it feels like something is rattling. its not all the time but enough for me to start worrying about it. Its feels like a stone being dragged under the front mudguard & ratting through & it sounds exactly the same, but its not.

Any ideas please?

thanks

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Pinking is when the fuel air mix in the cylinder is ignited by something other than the spark plug. it causes a violent burn (putting it simply) which makes a rattling / chuckling sound. The exact sound is dependent on the make of bike, amount of engine wear and cause of pinking.

Do not keep making your bike do it. Pinking will wreck little end, big end and main bearings and possibly hole the piston.

Common causes are retarded timing, advanced timing, insufficient squish clearance, coke in the cylinder, overheating, weak fuel air mix and poor fuel. If you are using ordinary petrol try BP ultimate or the better grade of shell or add an octane booster to your fuel.

Edit - I once bought unbranded petrol and all 3 of us who used it suffered pinking, switched back to Texaco and pinking disappeared.

Edited by dadof2
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Prolly a pinker ad dadof suggests. Ck your fuel and make it fresh!

Give the bike a good hard run to blow out the accumulated crap and grunge! Get some heat into it!

Even small changes in carby jetting can effect this, so be sure you are on recco spec for your area.

Now you are totally mind boggled, did we mention crap fuel?

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Thanks fellas

I am using shell fuel but not the high octane Vfuel. mixing 75ml of putoline 2t oil to 5lt of petrol.

I guess it may be the air fuel mix, I will have to have a look & re-set it today.

The engine has not been retarded or advanced but I guess wear can change settings.

I will get some V fuel today.

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Thanks fellas

I am using shell fuel but not the high octane Vfuel. mixing 75ml of putoline 2t oil to 5lt of petrol.

I guess it may be the air fuel mix, I will have to have a look & re-set it today.

The engine has not been retarded or advanced but I guess wear can change settings.

I will get some V fuel today.

That may be your problem !! If I am wrong somebody is bound to say but, I put 62.5 ml two stroke oil to 5 ltr of high octane fuel. I think this gives a mixture of 80 / 1

To put it simply, to much oil means LESS fuel and therefore a weak mixture which could cause the pinking. That was the way it was explained to me , if that is wrong it wasn't me your honour !!

Phil

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That may be your problem !! If I am wrong somebody is bound to say but, I put 62.5 ml two stroke oil to 5 ltr of high octane fuel. I think this gives a mixture of 80 / 1

To put it simply, to much oil means LESS fuel and therefore a weak mixture which could cause the pinking. That was the way it was explained to me , if that is wrong it wasn't me your honour !!

Phil

The Beta manual says 1.5% synthetic oil fuel mix which is 75ml per 5lt, but i must admit I think the last batch of fuel I got was 96 octain.

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Too much oil can cause pinking as pistonbroke says. Too little oil can also cause pinking because of raised piston temperatures. Your carburation need to be right whatever your fuel : oil ration. The next time your bike makes this noise pull the clutch in and stop the engine immediately. Check the plug colour. The nose insulator should be chocholate brown. Any lighter and your plug is too hot (wrong grade?) or your mixture is too weak - larger main jet needed. and maybe raise needle (lower clip). Also check float level.

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My Rev was kind of fuel fussy, I ran some ring free through it and by decarboning the top end it was noticeably better

But..... The detonation was at high rpm with low throttle opening (roads) not high load hill climbing

Maybe you should get a second opinion and maybe have someone ride it up a hill and duplicate the problem while you stand helmet off and listen

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The Beta manual says 1.5% synthetic oil fuel mix which is 75ml per 5lt, but i must admit I think the last batch of fuel I got was 96 octain.

Manuals being conservative as they are, most of us run between 70:1 and 80:1 with modern synth oils. The bikes will putt about all day at 100:1 with only occasional revving.

Do your own math, but more is not allways better!

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  • 2 weeks later...

Well I filled the bike up with 99 octain fuel & 80.1 mix of good quality oil & the engine seemed much better. I don't think it has cured it fully but much improved.

Now what happens is when I rev the bike hard when it is under strain there is a sort of single slap or tap as I quickly shut off the revs.

I moved the air fuel screw from 1 3/4 turns to 2 turns. I think I would be better having the engine set up properly at a shop but I still hope it is not a bearing issue with the bike being less than a year old.

what do you think?

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