SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> Pump or non-pump carburetor?
/cgi-bin/YaBB.pl?num=1351858157

Message started by Cavi Mike on 11/02/12 at 05:09:17

Title: Pump or non-pump carburetor?
Post by Cavi Mike on 11/02/12 at 05:09:17

I've decided on a Mikuni TM36 carb and I see they have a pumper option for this specific carb. Any thoughts either way to help make my decision easier?

Title: Re: Pump or non-pump carburetor?
Post by verslagen1 on 11/02/12 at 08:58:12

iffn you got a choice, pump it 8-)

the pump is meant to smooth out the transition from 1 range to another. Certainly does help in a sudden WOT.

Check out truckinduc's thread, he had a HD transplant I think.

Title: Re: Pump or non-pump carburetor?
Post by Dave on 11/02/12 at 09:01:33

My 4 stroke trials bike has an accelerator pump built into the needle jet. If you crack the throttle fast......it just goes like it is supposed to. No cough, gag, or Aaack like 4 stroke bikes could do in the old days.

Title: Re: Pump or non-pump carburetor?
Post by Cavi Mike on 11/02/12 at 14:58:15

Does it sound like it's worth an extra $100? The TM36-2(non-pump) is $150, the TM36-68 pumper is $250. I know I'd really like the extra kick in the arse off the line with the pumper but I guess I'm trying to justify $100.

Title: Re: Pump or non-pump carburetor?
Post by verslagen1 on 11/02/12 at 15:19:03

Depends... are we ever going to ride together?

Yes? then no not worth it. 8-)

Title: Re: Pump or non-pump carburetor?
Post by Cavi Mike on 11/02/12 at 16:02:26

Ha. Kick in the arse. I get it.

Title: Re: Pump or non-pump carburetor?
Post by singlesgoinsteady on 11/02/12 at 17:17:58

How do they work, do they need an electrical lead? Or where does the pump power come from?

Title: Re: Pump or non-pump carburetor?
Post by Gyrobob on 11/13/12 at 05:35:52

The pump is small. When you crack the throttle, a little diaphragm moves a bit, squirting a momentary jet of fuel into the air flowing through the carb.

Here's a good explanation of the Keihin carb's system. The Mikuni's is similar, but I couldn't find a good explanation. The priniciples are the same. http://www.thumperfaq.com/mxa_ap.htm

Here's a video:
http://www.youtube.com/watch?v=zsqMAMFle0k

The accelerator pump carbs are quite costly, and if the diaphragm gets mucked up, it costs maybe $200 for another diaphragm kit. Usually, though, a proper disassembly and cleaning will fix most acclerator pump malfunctions.

Title: Re: Pump or non-pump carburetor?
Post by Cavi Mike on 11/13/12 at 09:32:18

You'd be better off researching what a pumper is on a car carburetor. I'm sure there are plenty of videos on the infamous "Holley double-pumper"

Title: Re: Pump or non-pump carburetor?
Post by Gyrobob on 11/13/12 at 10:22:12

133126391D393B35500 wrote:

You'd be better off researching what a pumper is on a car carburetor. I'm sure there are plenty of videos on the infamous "Holley double-pumper"

Sometimes the pumps in auto carbs are pistons in cylinders, rather than diaphragms.

Title: Re: Pump or non-pump carburetor?
Post by Cavi Mike on 11/13/12 at 10:57:36

He needs to know what it is and what it does before he learns about different versions of it.

Watch closely at the little brass nozzle in the throat, it's the jet for the accelerator pump aka "pumper"
[media]http://www.youtube.com/watch?v=ZbzBbLYeATw[/media]

Title: Re: Pump or non-pump carburetor?
Post by Gyrobob on 11/13/12 at 11:39:32

5775627D597D7F71140 wrote:

He needs to know what it is and what it does before he learns about different versions of it.

That's what the video in reply #7 did.

Title: Re: Pump or non-pump carburetor?
Post by v-pilot on 11/13/12 at 17:45:00

Yeah it squirts fuel alright. My '87 Guzzi Le Mans 1000 has a pair of pumped 40mm Dellorto's Makes for a plenty snappy machine but when you chop down on the throttle it takes some time to use up all that fuel you just dumped in there. Just be careful and keep some fingers on the brake lever

Title: Re: Pump or non-pump carburetor?
Post by singlesgoinsteady on 11/14/12 at 22:15:27

Wow, thanks guys. I had searched Mikuni a fair bit online, but, never found an explanation or pictorial of the pumps.

I did read that the flatslides are touchier at low throttle, but, that the pumps on the ones with pumps alleviate that. Some instant throttle response would be nice. Like my buddy's Hypermotard for instance.... ha ha

Cheers -SGS

Title: Re: Pump or non-pump carburetor?
Post by singlesgoinsteady on 11/14/12 at 22:21:27

http://www.youtube.com/watch?v=YvT5Dte33No