Alternative carbs/carb swap

Black Panther/Street Moto, Baghira, Enduro, Mastiff, Skorpion Traveller and Tour.

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Alternative carbs/carb swap

Postby Yuna_Pup » Tue Apr 16, 2024 4:51 pm

Hey all, I have a 2000 baghira 660 and I was thinking of trying to squeeze out a few extra horsepower before changing cams, timing or going with a big bore kit.

Has anybody used a set of carbs from something like a 96-01 TDM850 ?

I know a few people have used the intake manifold from a 660 grizzly and gone with a single carb but it may require cutting a support in the frame, and I cant seem to find any of the intake manifolds easily in the UK.

Any thoughts or advice ?
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Re: Alternative carbs/carb swap

Postby breakwellmz » Wed Apr 17, 2024 4:34 am

Hi.

A less restrictive/lighter exhaust system to start, with suitable re-jetting.

I wanted a single carb (A CVK40 `pumper` carb) and started going down that route at one point. I thought the port centre-to-centre distance difference between the Grizzly manifold and the MZ head to be too much for an adaptor plate to accommodate. I also found i didn`t have the space within the frame (Mastiff) for it all to fit!
I ended making my own Heath Robinson version, I`m trying to find a picture of it but here is the RH side -

Cheers.
Attachments
MY CVK40 RH side.jpg
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Re: Alternative carbs/carb swap

Postby breakwellmz » Wed Apr 17, 2024 9:03 am

Here is the image I was looking for. Don`t laugh, it works for me!

Certainly not the `performance` upgrade I think you may be looking for, but the benefits for me are. -

1/ - Far better starting and idle.
2/- Increased low/midrange torque (So much so I had to raise the gearing to make first gear usable!)
4/- Improved fuel economy.
5/- Much quicker off the line.
Attachments
My MZ COPPER INLET.JPG
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Re: Alternative carbs/carb swap

Postby DAVID THOMPSON » Thu Apr 18, 2024 3:40 am

what size is the copper elbow i am getting ready to do this
to mine

Dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
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Re: Alternative carbs/carb swap

Postby droy » Thu Apr 18, 2024 10:57 am

for true performance your options are a double 35mm to 39mm set of Mikuni or Keihin carbs - new likely worth the same as the motorcycle. Do some searches in this forum for those and you find some info. If you look on ebay (USA) for a Edelbrock Quicksilver Raptor 660 carb you see a 2 to 1 manifold that works on our engine - I have it on a Skorpion but not sure if it hits the Baggy frame.
[b]Gang of Four
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Re: Alternative carbs/carb swap

Postby Yuna_Pup » Thu Apr 18, 2024 1:05 pm

Hey breakwellmz.

Your setup looks really nice !

I didn't know that was the case with the grizzly manifold :cry:

I already have a BSM end can on the bike and have changed the main jet on the main (small) carb from a 130 to a 135 with the mixture screw 5 or 6 turns out I cant remember exactly, the bike runs great and can consistently hit 95mph, though I would really like it to pull the front wheel up in 1st and maybe 2nd more.

Basically as much torque as I can get from it without drastically affecting it's reliability.

With your setup, would the missing carb not cause issues with lower air volume entering the engine ? Of course the air now has a much greater velocity which probably outweighs the lower volume especially when the throttle is open. Also, what is the copper tube to the other intake actually doing ? It seems like its at a very odd angle and would struggle to capture much air and fuel from the other intake boot but of course it works for you !

And finally, what kind of jetting are you running ?

I am not very experienced with this kind of thing so if I am talking total rubbish please tell me, just letting my brain run and spitting out the results :lol:
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Re: Alternative carbs/carb swap

Postby DII » Thu Apr 18, 2024 11:48 pm

On my Mastiff with stage 1 cam and 718cc ( stroke 88mm and bore 102mm) I use Mikuni flatslide from Kedo. Wery easy to set up and works like a dream.
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Re: Alternative carbs/carb swap

Postby DAVID THOMPSON » Fri Apr 19, 2024 5:47 am

i got spoiled by a BMW 1974 R90s it ran super for 40 years as a daily driver
the original carbs on the mz i an less than pleased
the only time a bike should run bad is it runs out of gas
and that can make you get ran over
BY A BIG TRUCK IN THE USA
dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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Re: Alternative carbs/carb swap

Postby breakwellmz » Fri Apr 19, 2024 9:06 am

DAVID THOMPSON wrote:what size is the copper elbow i am getting ready to do this
to mine

Dave


Hi David.

It`s a 15mm diameter elbow.

Cheers.
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Re: Alternative carbs/carb swap

Postby breakwellmz » Fri Apr 19, 2024 9:12 am

droy wrote:for true performance your options are a double 35mm to 39mm set of Mikuni or Keihin carbs - new likely worth the same as the motorcycle. Do some searches in this forum for those and you find some info. If you look on ebay (USA) for a Edelbrock Quicksilver Raptor 660 carb you see a 2 to 1 manifold that works on our engine - I have it on a Skorpion but not sure if it hits the Baggy frame.


I don`t feel there is any room within a Baghira/Mastiff for any off the various options of 2 into 1 manifolds that have been available, there just isn`t the space compared to a Skorpion frame.
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Re: Alternative carbs/carb swap

Postby breakwellmz » Fri Apr 19, 2024 9:26 am

Yuna_Pup wrote:Hey breakwellmz.

Your setup looks really nice !

I didn't know that was the case with the grizzly manifold :cry:

I already have a BSM end can on the bike and have changed the main jet on the main (small) carb from a 130 to a 135 with the mixture screw 5 or 6 turns out I cant remember exactly, the bike runs great and can consistently hit 95mph, though I would really like it to pull the front wheel up in 1st and maybe 2nd more.

Basically as much torque as I can get from it without drastically affecting it's reliability.

With your setup, would the missing carb not cause issues with lower air volume entering the engine ? Of course the air now has a much greater velocity which probably outweighs the lower volume especially when the throttle is open. Also, what is the copper tube to the other intake actually doing ? It seems like its at a very odd angle and would struggle to capture much air and fuel from the other intake boot but of course it works for you !

And finally, what kind of jetting are you running ?

I am not very experienced with this kind of thing so if I am talking total rubbish please tell me, just letting my brain run and spitting out the results :lol:


The copper elbow supplies the smaller of the two inlet ports.
Increased inlet charge velocity due reduced carb area is exactly the reason the torque is produced at lower revs, I do have slightly less `top end` though I`m sure
What also improves throttle response greatly is the fact the the CVK40 is a CV carb with a "pumper", a good all round sort of carb in my opinion.

I have got all the bits now to proceed with this sort of thing, just need more time! -
Attachments
COPPER IN2.jpeg
COPPER INLET.jpeg
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Re: Alternative carbs/carb swap

Postby breakwellmz » Fri Apr 19, 2024 9:35 am

DII wrote:On my Mastiff with stage 1 cam and 718cc ( stroke 88mm and bore 102mm) I use Mikuni flatslide from Kedo. Wery easy to set up and works like a dream.


Hi.

I had a look at those, nice. Are both carbs the same size feeding inlet ports of different sizes?
I`m too mean to spend that sort of money on a pair of carbs! I`d love to have a go on your bike though, it must be a beast!

https://www.kedo.com/mikuni-tm34-flat-s ... orked.html

Cheers.
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