BVF 30N3

[Blurredman]

Can someone please tell me or (take a picture?) identify how far the slide guide pin should be protruding from the side of the carburettor.. ?

Mine seems to have come loose over time. It doesn't look like it will disapear into the engine, but it has the ability to move around slightly and I'm wondering if that may be a cause of my intermittent rpm hang issue....

I think it's movement has possibly gouged the slide slot and possibly restricting the slide from fully relaxing (maybe). This theory may be unfounded however as the throttle snap is quite nice and quick and seems to go back all the way.
My 'rpm hang' seems to take place if the throttle is snapped back so it may not be the cause after all...


Would be gratefully appreciative!

[Puffs]

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[Blurredman]

Does yours wiggle?

[Puffs]

No, my slide only jumps cheerfully up & down . The pin doesn't move, it's fixed .

[Blurredman]

Well everything seems okay. The pin is still secure and by punching it through (only lightly tapping) from the outside of the carb and then securing with loctite seemed to have done the trick. But I don't think for very long.

Anyway- Just about everything seems to be running well. The cables no longer influence the throttle depending on which direction the lamp is pointing..

There is one niggle however that I am pondering on. The idle is a little higher than it used to be (at around 1500 instead of 1300). I've packed out the mating points of the carburettor and checked the manifold leaks. There doesn't seem to be any- but I would expect more random idle problems if there were- as it is, the idle is steady and always sits at the same place. But higher.

I haven't changed anything carburation wise- I double checked all my settings from last time I adjusted them and they were all the same:

Air bypass: 3.5 turns
Pilot bypass: 2 1/4 turns
Needle clip position: Middle.


Not only is the idle higher, but there is a distinct pinking (i believe it's pinking- it's one of those things I've always found hard to detect) at 3700rpm-just before 4k. I can power through it but part throttle the bike falls on it's face a little at that rpm..

Wondering the two are connected- too lean? But I've not touched the carb settings (other than pilot) for years. Maybe I will raise the needle 1 slot before I ride my bike home from work and see what it feels like then..



I'll also check the air filter tonight to make sure that's in once piece and not blocked. Or even holed..

[Puffs]

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[Blurredman]

Well- Made the bike richer on the way home, but I could tell it was much worse- so instead I made it leaner than it was before (2nd from the top) and it ran pretty much how it has always been.

Got home and took a look at the filter and it was thus:

It's dirty and very likely very beyond it. I don't know what it is from (if it isn't MZ) and I don't know how old it is either.
I've bashed it on the floor many times and re-installed it. I've also put the needle in the default middle position. Will see how it runs in the morning- If I find the same symtoms as I have recently then I know it's running rich and either leave it in a leaner position until I manage to get a new one, or nab the one from the other bike..

Numbers written on it are part number and not mine.

What intruiges me is that i've double checked for air leaks, and can find no discernable reason why this would suddenly be the issue- after being in there for so long..

[Blurredman]

Just for reference, this is the spark plug after 15 miles on the leaner setting ...
It looks lighter than ordinarily, but seems very passable..

[breakwellmz]

Dump that filter!

[Blurredman]

It's the only one I've got at the minute until mz-b get more stock. I'm not paying those e-Bay prices when I have three to buy.


Anyway.. I went out for a little jolly and all seems well! Everything as it was working only a fortnight ago.. happy..!

[Puffs]

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[parrbd]

I am using these, https://www.sparesbox.com.au/part/ryco-air-filter-a22 A ryco A22 which is used in ride on mowers. I glue on a foam ring on the airbox end. Seems to run a bit leaner but fixed with the usual adjustments.

[Blurredman]

That's not bad Parrbd.. But for me still not a viable option when 'official' ones are unavailable/too expensive.

[Blurredman]

I forgot to mention that I took the filter from my '87 ETZ 250. It's fair looking. It'll do for now. :

[motorclocks]

Would a BVF 30N2 work I have photo