New Mikunis

[reverendzed]

Hi guys, well the triples are on.......BUT....I NEED HELP!  I've included a few photos because I'm not sure about a couple of things.

1/ not sure if there is meant to be a fuel return line on the bottom of the carbs and if so how and where does this go to?

2/ I have a vacuum pipe coming from the block and not sure if that needs to be hooked to something

3/ the 3 lines running from the fuel system have got me beat, one goes to the filter from the electric fuel pump, I know that one went to the charcoal cannister (that I ripped out) not sure if the other was a fuel return line, I've hooked the 2 of them together as fule was leaking out, not sure if this is the right think to do.

I'm trying to get this right to be able to make it the club meet tomorrow night, so I would appreciate any help.

Rev

[Toecutter]

Hi Dave,

 

1. Not familiar with Mikuni's but Im sure they would be similar to Deollortos. They almost look like some sort of over pressure line, mabye fuel relief?

 

2. Just put a small filter on that pipe. It allows pressure to relieve from the crank and bottom end.

 

3. The one from your pump obvioulsy goes to the carbs, the other should be a return. Hard to tell from the pics.

 

Sulio

 

Does it start?

[Scoota G]

They use Mikunis on Harley Davidsons and jet skis so might need a part number to surf more accuretly.

 

Or try this

 

http://www.rmcarburetors.net/

 

Found this while surfing too

 

www.formulagti.com/Technical%20Resources/Jetting%20and%20Tuning%20Weber%20Sidraft%20carbs.pdf

 

I must mention that i have no experience with these carbs

 

http://www.toymods.net/forums/showthread.php?t=19030

 

Found a few diagrams here

[reverendzed]

Hi Sulio,

Yes it starts and I can drive it however it is a little 'flat' with some backfiring through the carb.  I also noticed fuel leaking from under the carbs when I turn the motor off, which is probably due to the fuel return isssue.  Do your Delorto's have a fuel return and what does that setup look like?

rev.

[reverendzed]

Could someone let me know how their fuel return works on their triples, if I can get that nailed I may make it the Meeting tomorrow night.

Thanks

Rev.

[C.A.R.]

Someone help the Rev. STAT!

 

I believe there’s a free blessing in it for you

 

[Zedman240®]

Hey Rev, do you still have the original fuel rail that was on the engine? The one with the fuel return (two metal lines that go around the engine across the front and hook up to the fuel line and fuel return line). Fuel to go to the carbs then excess fuel goes back to the tank. Those two hose connections under the Mikuni's are next to the accelerator pump for the carb and I haven't seen those before. Daniel! some help here! (Dazzed). Like Sulio mentioned before, that large metal pipe out the side of the block is for crankcase ventilation.

[Toecutter]

Rev,

 

Good advise from Dimitri, use the original fuel rail as it will allow you to run the return. It could well be that they are over pressurising at low revs as this is what happend to me when I ran without a return. If you don't use the stock fuel rail you will need to the right connection on the last carb.

 

Here is a pic of how I set them up with stock rail and it worked well.

 

sorry about the quality.

 

 

Sulio

[crowe]

Hey Rev, i have just done this myself.

 

Best to use the orginal rail if you can, just makes it a bit easier. I cut mine to modify it and regretted it afterwards. The orginal rail also has a smaller opening in the return line which slightly restricts fuel pressure going back to the tank, giving more pressure on the carbs. The dripping fuel you now have is too much pressure, using the standard pump with the standard fule rail should give you better pressure.

 

I would not join your return line and the fuel tank evaporator line togther as pictured in photo, the evaporator line does not go back to the tank directly and is for gases only, you dont want fuel in this line. You may want to permanently cap this if you have removed the carbon canister, this will prevent fumes or smell of pertrol under the engine bay.

 

I used webers not mikunis so cant help on the other questions but crank case ventilation should go to an oil catch tank with breather on top. The vent (pcb) on top of rocker cover should also go to this same tank.

[dazzed]

i purchased a set of solex mikunis carburettors many times, one particular set i purchused from a well known of person, .  sripped all the genuine internal functioning parts and replaced them with parts from other carburettors then fitted those parts to housings that had bent shaft spindles and warped throttle bores ,,,, consider ripped orf big time buddy not impressed, certainly learnt me a lesson when it comes to requiring solex mikunis again, but in all of that , guess what??  what? my car goes good real good awesome in fact and the motor not good, built in 1992 with the help of rob an lindsay from z spares in clayton it still goes tho i think by now the piston to bore clearance is the same as the spark plug gap

[260Coupe]

Dan

 

I purchased a set of remanufactured 44 Mikunis from Wolf Creek Racing, these are completely reconditioned to 'as new' with new throttle shafts, butterflies, linkages and all soft parts, the throttle linkage is also modified to be a straight swap for the standard 240 carbs using the original throttle yoke from the fire wall. The carbs are fitted with 34mm chokes and come with a spare set of 37's and various spare air and fuel jets (they build the carbs to roughly match your engine specs and prvide spares to fine tune)

 

Wolf Creek also carry a large range of spares for Mikunis...............you may want to get onto Todd at Wolf Creek if you need spares.

 

http://www.wolfcreekracing.com/

 

Here is a shot of my carbs ready to ship 

 

Alan

[Cdr Zero]

I have a new-to-carbs type question, would I be able to buy a set of these and put them onto an L28 later on?

[260Coupe]

No reason why not ..........Mikunis are probably the most expensive of the triples (Webers are Dellortos can be sourced for considerably less $$ as they are more common).......however the Mikunis are arguably (IMHO) the best of the triple carb set up with better throttle response thru mid range and top end power(They are also set and forget....no constant maintenance as they do not go out of tune unlike some other types)

 

BTW

 

Steer well clear of the latest Spanish made Webers sold on the ebay ......stick to the Italian Webers

 

cheers

 

Alan

[NZeder]

Having owned a set of OER carbs I can say they are a great carb, I have had zed with triple webers, dellortos, and Mikuni's and the OER have been the best of the lot. Reason are - they are designed as a race carb and can with stand blow through set up if turbo is your thing. They take Weber jets and tubes but have the better idle circuits like the mikuni's. I also believe someone here in NZ flow tested a 45 OER vs a 45 weber and the OER flowed 63cfm more so that is a good thing for performance.