490 bing/mikuni conversion

[huskibul]

    Hey guys, got any tips and baseline jetting specs on converting 490 alpha 1  bing carb to flatslide mikuni (38-40mm?)anything would be much appreciated cheers

[crabman]

Hi
I have got three Maico's - two with Bing's and one with a Mikuni 38 mm flatside. I am at work currently and I can help you with the jetting on both types of carbs. Personally I would stick to the Bing carb -believe it or not it does work better than the modern Mikuni's. Either way I can help, will follow up tonight. regards Gavin

[huskibul]

  that would be great crabman,this is one of a mates bike's  which he use's to bring over for a ride but it started getting to hard to start,the slide is worn and iam suspecting the needle and jet as well, does not respond to well to adjustment  ,thought the carb would be the best place to start,it has a pvl ignition so i'am ruling out electrical at the moment,do you know if you can get bings resleeved?,i heard somewhere you can buy new bings in uk ?maybe thats the way to go if theres no performance gains in a flatslide cheers

[Hoony]

someone else here (allthings414) has mentioned you can still buy new bings from the us or canada. there is a thread some where on it (over to you Alison)

[Lozza]

 maybe thats the way to go if theres no performance gains in a flatslide cheers

There is a massive difference is the performance of a flat to round slide. A Mikuni is a far better carburetor, needle jets don't wear spares readily available etc etc

[huskibul]

    Yes lozza,still may be the way to go, ive done couple of mikuni conversions to my bullies,and never looked back ,just like to try and cover all base's especially with someone else's bike cheers.

[All Things 414]

Yeah. Mikunis on Euro bikes is a better way to go if you're not real good at tuning a carby and don't ride very quick. If you have some nouse though and want your Euro to go like it should, get a Bing.

[huskibul]

 Hi all things do you know if you can resleeve bings ,have you had any done and where? i find the euro carbs a breeze to tune when their new but wear fairly quickly once they start and turn into problems, stainless sleeve seems to be the go ? i put alot of seat time on my bikes :)thanks for your opinion

[JohnnyO]

You can get the Bing re-sleeved, i know someone who had theirs done. I'll try and find out where.
The Bing is the way to go on a 490, myself and a couple of mates have tried Mikuni's on Maico 490's and gone back to the Bing.
Make sure the slide is not worn and use a new needle jet and needle and the Bing is great.. more horsepower over a broader range.

[All Things 414]

I've bought new carbies and heaps of bits from this mob over the past few years.

http://www.bingcarburetor.com/aboutbing.html

Always been able to get the bits that I want (as well as a few grouse Bing T-shirts )

[huskibul]

 Thanks heaps for that johnnyO thats exacty what ive been wanting to hear, first hand info,the slide is badly worn,maybe don newell for a resleeve as well as  new slide ;)thanks for the site 414 i'll check it out :)anyone have baseline jetting specs@sealevel for the bing?cheers

[Lozza]

Yeah. Mikunis on Euro bikes is a better way to go if you're not real good at tuning a carby and don't ride very quick. If you have some nouse though and want your Euro to go like it should, get a Bing.

  The dyno and stopwatch awaits your presence

[All Things 414]

Lozza. You seem to confuse horsepower with speed. How much HP do you think a motocross bike really needs? 40, 50, 120 HP? How quick is a rider on a bike that steps its rear end out every time you touch the throttle? I'm talking about a bike performing at it's very best. Not a gain of .5 HP here or 1 HP there at the expense of handling.

[All Things 414]

If it was all about HP how come those yanks on their 125's were beating 500's in the GP's in the 1980's?

[JohnnyO]

A dyno doesn't work for motocross. On a real motocross track you are only at full throttle for a small amount of time each lap.
The dyno only gives a full throttle reading..what about when you're coming out of a slick dry hardpack corner and only using 1/4 to 1/2 throttle on a 490.
Power delivery is more important than numbers and a properly jetted Bing gives good power delivery.