Topic: v twin carb and intake ??

[bountyhunter]

ok we are working on a built vert. Vtwin kohler it apears to have stock aluminum intake the engine came with the midwest super cub 1bl carb ( 1.5 thottle plate and 1.2 ventyry) it has the adapter plate we cant seem to get engine to run right over 1\2 throttle, heres my ? The hole in intake and adapter are a LOT smaller than the 1.5 on the carb  do we need to  bore intake and adapter out to the 1.5 , is this even possible. Is there better intakes\carb set ups avalleable for this engine also the carb sheet says 4 2-4,5 psi what does stock wlaboro pump put out for pressure, in the carb there is a spring on float assembly can we remve that and run less pressure! Gust want to get this running right! Thanks

[FlatheadPuller]

Ferris we run the same carb on our 45cid roller motor. Never tried it on a vertical. Does it have a two bbl vertical intake? If not it will need one for that carb. And yes you have to port the adapter to match the carb. Also might have to weld up the back side of the intake when porting. We had to on our horizontal 2bbl intake. I dont think the pulse pump will keep it feed at wide open throttle. The spring is to help the float from moving around and flooding the carb. The jet in the carb at the 3 oclock position is very tempermental. We run ours closed right off. Just using the idle mixture screw at 1 oclock and the bottom adjuster. I dont know if that carb was ever meant for roundy roundy stuff. It works good at wideopen throttle. How built is the engine. You might want to try a 1.0 carb or use a down draft pumper carb. smaller venturi, better throttle signal and it has an accelorator pump. You can have them machined for an adjustable main as well. Put it on a plastic vertical intake. The pulse pump would be able to keep with it as well. We run an electric fuel pump with a 3-7 psi built in regulator. no regulator inline. Its a square ticker pump from napa. keeps up with it at 8500+

[bountyhunter]

Ok it has the one bl intake  and soppossed to have good rods ,mwsc heads ,roller rocker, not sure bout cam specs but its sounds pretty stout, do know the original builder ran a 28 mm mikuni and turned it to like 6500 and it REALY ran strong but when he sold it someone else owned carb so the guy we got it from purchased the mwsc carb but never run 100 percent sence! We just got it and or going thrue it this winter just trying to fig out wether we need the carb or go  to something elseDennis thanks for info, to me its way to much carb for intake and desine of the intake leaves alot to desired as it makes very sharp turn at the transtion and also it seems realy finicky to adjust in idle side but got that and trans good but anything over 1/2 throttle will not run right no matter were main is think it to much and with adapter and intake holes being much smaller think it makes to much turbolance  to run right prob go back to something smaller! But need to fig out what lol might have mwsc carb 4 sale also missed you at Sumner days pull think I talked to your cousin again thanks for info                                 

[FlatheadPuller]

eah I havent pulled much this year. Kids are in sports and you cant get a do over with that stuff so pulling is kinda on the back burner for now. A stock 2bl vertical intake and 2bbl carb would work well. Our 45cid open roller motor isnt close to using all the 1.200 carb. I dont know what were making for hp but I can make a good guess at close to 70hp.

[bountyhunter]

Dennis when you say roller you meen roller cam right?
we are not limited to any thing carb wise so that sounds like a way to go! im wandering if a hd tilley or warbo pumper would work to! like the adjustable jets! i have several of these of snowmobiles in my garage or maybe 2 hl's or hr's tillys if we could find!or make adapters!

[FlatheadPuller]

Yes solid roller lifters, billet steel cam and roller rockers. Personally I would run a 2bbl carb and intake for a vetical. Midwests velocity stack and air cleaner. They have the jets for them now and can help set it up. The pulse pump will keep it feed. If you were in sumner you prolly saw our open tractor.

[bountyhunter]

what kind color was it talk to one guy with kohler super cub engine

[FlatheadPuller]

Our tractor is a cub with JD round fenders and 110 sheet metal all green. JD yellow steel pan seat. Aluminum wheels all around. The valve covers are from super cub. Nice tractor, low in the front, header comes out right side. Look in some of my videos on heymow. Its on here.

[bountyhunter]

Yes i think I remenber it was disapointed got rained out was looking forward to seeing them pull does mwsc sell more than just one roller grind for the cam ? And were does yrs start making good power at and were do you think its maxing out at? No Ryan talking 12500 rpms dont think we need that rad a cam! SORRY bout all ?s just trying to learn the ins and outs of a kohler!

[FlatheadPuller]

Stock heads with stock port locations will tend to fall off around 8500. Ours turns 8500 leaving the line. It just won't rev any higher. Ports won't flow well enough and our heads had extensive flow bench time. We have big valves as well. A little less lift and more duration might get a little more rpm but not sure if your gonna make hp there. Ours runs down the track upper 7's. Our cam is from vogel. He does make milder roller cams. MW uses hackman cams. A ported and modified head that uses stock intake bolt and flange pattern will not support huge rpm. Roundy rounders would prolly have good luck using mildly ported heads and a little smaller cam. You'll have a hard time putting the power to ground anyway. We have a hard time with the tires we use.

[bountyhunter]

Dennis we dont realy want a mild just anough engine we want need way more hp than what we can hook up been down that road be fore no fun gettin out powered on the straights when u have better chassis and driver nope to much hp is were we  want to be at!  Try to hook up is a prob we want lol are you running stock crankshaft how much will they hold! And 8500 seems to be about what ive been thinking

[FlatheadPuller]

We use a stock crank. 25hp heads, 3.307 bore stock stroke. je slugs, long rods. comp pushrods, roller rockers, springs. down size the valve stem diamter, bigger than stock valves, major reworking on the heads and ports. They spent alot of time on the flow bench. Our engine would not run like it does if it werent for our heads and the machine shop that did the port work. The 30hp heads shroud the intake valve too much. proved it on the flow bench. Thats why we have 25hp head castings. midwests crank trigger. last year we had a smaller hackman cam. switched to this big roller and would never go back. it turns hard and makes a ton of torque.

[bountyhunter]

Ok wil ptop get ahold of u a little later thanks again for info!