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aj201280

New Rev 3 Mikuni Carb?

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My mates 07 bike was pouring fuel out at an alarming

rate the first time he took it out,so off came the carb

to have a look and found the cause of the problen

on this occasion to be the float bowl gasket!

It was sticking out into the bowl that much one of

the floats was fouling on it causing the thing to

stay stuck down.The gasket was correctly fitted

but was to wide so cut it down job done.

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Did you leave the fuel tap turned on?

It's annoying when a new bike does something like that, do a search on TC and/or www.r2wtrials.com for the Beta mods. Try the BillyT method first off and if that doesn't cure it, get the carb drilled and plugged at Lampkins or DIY it...

Everything else ok with the bike apart from incontinence? :chairfall:

The fuel was left on, I know everyone is going to say just turn it off but the bottom line is that a bike should not leak fuel from the crab like that. I won't go in to the loose bolts everywhere! :bouncy:

Bike rides well so hopefully after I've spent some time in the garage I can grow to like it.

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Yep sounded like mine when I first got it but like you say spend a little time on it (which really you shouldn`t need too on a new bike!) lock-tite all the bolts do the carb float adjustments and you`ll have the biggest grin :chairfall: everytime you go out for a ride

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What strength Loctite are you using? Did you do all the bolts, which ones sre really bad?

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what ever I get my hands on for strength really apart from the rear brake pivot bolt for which I use some ultra strong stuff as with the lesser ones mine still keeps coming undone! :chairfall: So I guess just give whatever you have a go or just get something mid strength

I admitidley don`t do all the bolts just the ones I find loose on my after ride bike check and clean:

So on MY bike the worst ones have been:

1. Front frame strut upper bolts

2. Rear brake pivot bolt

3. Rear disk bolts

4. Top shock mount!!!

5. Rear bash plate bolts

Think they are the worst ones from memory could quite possibly be more but I can`t remember

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Which loctite number you using though, there's loads of them! 243 etc. I found the tripple clamp bolts where lose, this caused the forks to twis and bend the fork brace that the front guard rivits to. These bolts coming loose could cause a real injury, imagine droping off a rock and the forks moving yp the clamps! I plan to loctite them in, along with all the others and then witness mark them. That way I know if they've moved with out using tools and then breaking any loctite. Even thought about wirelocking where poss.

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Which loctite number you using though, there's loads of them! 243 etc. I found the tripple clamp bolts where lose, this caused the forks to twis and bend the fork brace that the front guard rivits to. These bolts coming loose could cause a real injury, imagine droping off a rock and the forks moving yp the clamps! I plan to loctite them in, along with all the others and then witness mark them. That way I know if they've moved with out using tools and then breaking any loctite. Even thought about wirelocking where poss.

Honestly couldn`t tell you as the bottles a tad worn as in it has nowt written on it anymore!

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Hello boofont, I find that the 243 loctite seems to do the trick. I have tried the 271 but it is a pain to remove the bolts using hand tools with it.

When you get all those loose bolts sorted you will love it! (but you really should not have to deal with that)

cheers

Mike

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read these carb problems with great interest have a 06 250 leaked fuel from day 1 , done all mods including drilling out ,stopped fuel leaking out, bike runs great ,i donot want to change carb, but it will not start facing down hill, if you are queing for a section facing down hill, it will not start have to bouunce it round level then starts, can someone tell me why??? ,

what is the petrol flooding, if it is, if I knew the problem i might be able to stop it, any ideas anyone. please dont say turn it off at each section, thats a joke.

This carb problem is spoilling what is a gret bike for me, this is my first beta and proberly my last, someone should have sorted this years ago.

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Not sure why they do it, but could be getting in the cases. If I'm waiting in a section line up downhill I always keep the bike ticking over, walking a section always leave it uphill and if it has to lie down knock the fuel off. Pain I know but thats how it is, always will be, great bikes though

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Just to let you know, recently bought a 1999 250 techno, and found to my dismay it was leaking fuel from the carb, Big Time !

Tried the Billy T method, and it seems to have done the trick :bouncy:

Didn't fancy drilling the carb, but will do the mod if need be.

Cheers yal Neil :chairfall:

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I think that the 'Billy T carb mod' should be enough really. I have found it to be fine on both my bikes.

I think i read somewhere that the carb drilling mod which does stop the spillage can also cause flooding slightly more easily, and Lampkins now only recommend it if you are doing the scottish or such like where every drop of fuel counts.

Just my experience,

Bob

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I had two 250 rev 3's . neither would start when pointed downhill. I made it better by reducing the float height height but it wasnt perfect.

heres somthing to demonstrate why it happens.

take off the carb but leave the fuel line connected, let the bowl fill as normal. Hold the carb level and slowly tip it forward whilst looking in the front part of the carb which fastens to the reed block. keep it a safe distance from your face though as you'll see petrol come up through the pilot jet as you tip the carb forward. So I presume if you park it with the bike facing downhill petrol must run into the reedblock via the pilot jet, this then merrily floods your engine.

why doesnt this happen on a dellorto ?? lower fuel height in the bowl?? different design ?

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Funny from day one had a 03 250 and you could not park that

facing downhill otherwise it would flood and be a pig to start.

Got an 06 and that does not do it at all park it on any

incline and it makes no difference still starts perfectly.

this is with a carb as it came from beta no mods so

why do some do it and others not,it has to be due to

quality control on the carbs!

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Considering the rev3 been in production for 7 years,don't you think the factory should have sorted this by now.Not right on an item that costs

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