Heymow - Lawnmower Racing Forum

Engine Help => Other Engines => Topic started by: Racer57 on June 07, 2013, 02:55:03 pm

Title: Kawasaki fh721v questions
Post by: Racer57 on June 07, 2013, 02:55:03 pm
I have a Kawasaki fh721v twin how much and what do I have to put into it to make a competative super mod, where do I get the parts from?
Title: Re: Kawasaki fh721v questions
Post by: Darkviper on June 12, 2013, 03:46:18 am
I know Jason is the guy hes in Sparta Michigan I don't know what his heymow name is but he runs supermod with kawaski v twin you should ask him about it. Its really good engine if you find the horizontal shaft one that's what he runs. From what I herd Jason made his own and cost him 500 dollars to make a flywheel.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 09, 2013, 01:41:29 am
hello, l race a mower in queensland Australia with a Kawasaki 721v 25hp v twin motor, and want to put a dominator carb on it. could someone let me know if they have done it, or knows someone else who has done it, if I will need to buy an adapter plate, or will it bolt straight on to my engine. I would also really like one or more contacts for either of these items please [ prefer email address if possible ]. thanks. NEIL.
Title: Re: Kawasaki fh721v questions
Post by: redline on October 09, 2013, 08:17:52 am
Dominator as in , Holley, or E.C.?
Title: Re: Kawasaki fh721v questions
Post by: Eatondirt on October 09, 2013, 03:41:35 pm
Of course a holley Ed I think I would go with a 1050 !   Go big or not at all
Title: Re: Kawasaki fh721v questions
Post by: redline on October 09, 2013, 06:47:08 pm
Well then, I would go with the annular boosters over the downleg boosters....
Title: Re: Kawasaki fh721v questions
Post by: Burwell555 on October 10, 2013, 01:48:44 am
A "big" Holley dominator is at least 1400 cfm  :roll:  should be able to feed a v twin with one??
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 10, 2013, 09:44:33 am
I preferred the 1150 win annular boosters. Going to need a 90 degree adapter.....

Lester
Title: Re: Kawasaki fh721v questions
Post by: redline on October 10, 2013, 01:14:53 pm
Annular boosters. Lester knows.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 14, 2013, 02:55:19 am
the dominator carb l was asking about isn't a holly, it is a carby that fits on small vtwin motors like 25hp Kawasaki and 28hp briggs and other similar motors [ made in USA I am told]. l am also after a billet fly wheel for my Kawasaki 25hp fh721v if any body can help. thanks.
neil.
Title: Re: Kawasaki fh721v questions
Post by: Darkviper on October 14, 2013, 05:25:41 am
You have to make your own because only other person i know that races with billet flywheel is jason makila
Title: Re: Kawasaki fh721v questions
Post by: GRUBDIGGER on October 14, 2013, 06:40:46 am
the dominator carb l was asking about isn't a holly, it is a carby that fits on small vtwin motors like 25hp Kawasaki and 28hp briggs and other similar motors [ made in USA I am told]. l am also after a billet fly wheel for my Kawasaki 25hp fh721v if any body can help. thanks.
neil.

USE THE KAWASAKI CARB. EASY TO TURN INTO A RACING CARB THAT WORKS VERRY WELL.
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 14, 2013, 10:01:47 am
Dustin,
What I did to make the 6011 ARC wheel fit my Kawi single was to chuck the crank in my lathe, get it trued, then carefully adjusted my compound until I found the correct angle for the taper. It took a while but once I had it I took a piece of 1 1/2 stock and first drilled it to the smallest measurement of the taper. I then cut the taper. I then chucked up the hub (it was an Intek hub) and bored it to a .0015" press fit for the tapered sleeve. I drilled 2 plug weld holes into the hub as well then pressed the sleeve into the hub. I assembled the hub/wheel and adjusted the sleeve to get the proper position for the wheel (height) on the engine (I had a complete engine minus the flywheel and another crank so it was much quicker than having to re-assemble the engine). I then welded the sleeve through the plugs and put the hub back in the lathe and turned the welds (and hub) smooth. I then put the hub on my crank, trued the crank in the lathe and trued the hub (took .005" off just to be sure it was true). I then took an Intek ring gear and machined it down to the same size as the original flywheel (the ring gear is heat pressed on). Just heat the ring gear evenly and it will fall off. When the ARC ring is turned to the correct size simply heat the ring gear back up and slip it on the ARC ring and let cool. I need to clarify: I did the ring gear FIRST, assembled the flywheel, the pressed the hub to the desired location I needed to get the starter to mesh correctly, then welded the hub.

Lester
Title: Re: Kawasaki fh721v questions
Post by: Jim Knutson on October 14, 2013, 10:29:55 am
the dominator carb l was asking about isn't a holly, it is a carby that fits on small vtwin motors like 25hp Kawasaki and 28hp briggs and other similar motors [ made in USA I am told]. l am also after a billet fly wheel for my Kawasaki 25hp fh721v if any body can help. thanks.
neil.
if you are referring top the EC Dominator series 2bbl carburetor for the v-twins, yes it will bolt to a kawasaki v-twin 2bbl intake.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 14, 2013, 11:39:51 pm
thanks for every body's input. l am still hanging out for more info on billet flywheel for Kawasaki fh721v 25hp twin.
neil.
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 15, 2013, 01:11:39 am
thanks for every body's input. l am still hanging out for more info on billet flywheel for Kawasaki fh721v 25hp twin.
neil.

I did. There is no ARC wheel or any other that I know of for the Kawi V-Twin. Same goes for all Kawi's except the FB460V.

Lester
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 16, 2013, 04:02:24 am
looks like it is very hard to get a billet flywheel for a Kawasaki fh721v, has any body had there cast iron flywheel machined [lightened] with a very very heavy duty guard around it for safety?
Title: Re: Kawasaki fh721v questions
Post by: birdman_express on October 16, 2013, 06:28:24 am
looks like it is very hard to get a billet flywheel for a Kawasaki fh721v, has any body had there cast iron flywheel machined [lightened] with a very very heavy duty guard around it for safety?

Do not lighten ANY STOCK FLYWHEEL PERIOD. It is not legal for racing and will get you hurt.
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 16, 2013, 09:54:04 am
Do not lighten ANY STOCK FLYWHEEL PERIOD. It is not legal for racing and will get you hurt.

It is just as easy to modify the steel hub of an ARC wheel as to lighten a flywheel and 10 times safer (or more). I forgot to add that once the hub is finished I simply placed the ARC wheel on top of the stock wheel, aligned the magnets and marked the keyway and broached (cut) it. I check my timing with a light and it was close enough for that.

Lester
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 16, 2013, 05:03:00 pm
ok, thanks.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 17, 2013, 02:59:05 am
Lester,
         I am new at mower racing as you can probably tell. when you write ''easy to modify the steel hub'', from what l can see the steel hub is just the inner part of the billet flywheel, that sits over the end of the crank, with the o/d much smaller than the flywheel's o/d. Am l looking at a different type of steel hub to the one you are writing about?
neil.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 17, 2013, 03:32:14 am
hello,
       can someone tell me what the timing settings is for Kawasaki fh721v and which is number one cylinder [ left or right ] please.
neil.
Title: Re: Kawasaki fh721v questions
Post by: jaysonmikula on October 17, 2013, 09:02:18 am
Cylinder 1 is the one closest to the flywheel.  Cylinder number 2 is farther away.  If you look at the flywheel the way it rotates it comes to cylinder 2 then 1.  Stock timing would put the flywheel magnet centered over the breather cover when cylinder 2 is at top dead center.
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 17, 2013, 11:10:26 am
Lester,
         I am new at mower racing as you can probably tell. when you write ''easy to modify the steel hub'', from what l can see the steel hub is just the inner part of the billet flywheel, that sits over the end of the crank, with the o/d much smaller than the flywheel's o/d. Am l looking at a different type of steel hub to the one you are writing about?
neil.

Yes. For the most part ARC uses one flywheel (the aluminum part) 6011 for most mower engines. It has different hubs for different engines and starter ring gears. Each part bolts to the flywheel making production more cost effective.

Lester

L
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 17, 2013, 05:08:45 pm
thanks very much for that info.
neil.
Title: Re: Kawasaki fh721v questions
Post by: nsbeck42 on October 17, 2013, 05:41:36 pm
 
Hello Lester,
                 Thanks for your help. What motor steel hub did you start off with, and did you take your whole motor to a machining  shop for them to machine the inner part of the hub?
neil.
Title: Re: Kawasaki fh721v questions
Post by: more4les on October 17, 2013, 07:00:20 pm

                 Thanks for your help. What motor steel hub did you start off with, and did you take your whole motor to a machining  shop for them to machine the inner part of the hub?


I started with an Intek hub and ring gear. Funny part is the actual wheel was from a Briggs single. The hub was sent to me by mistake and someone from here had a stripped out Intek ring gear.

Lester