Mikuni-Solex Tech Info

[@andrewsr00]

Thanks for the info!! I'm reviving a set of 44 right now that were pretty far gone.

[@Mercedes-Guru]

Excellent. Enjoy working on them. They are a very satisfying project.

[@sschultze4260]

Thanks for this video and information. I have a pair of Solex ADDHE 48 on a race car. Where can I get a manual (or information on the manual) like you show? Any hints on a leaking accelerator pump diaphragm? I replaced with a new diaphragm and have a small amount of fuel leaking.

[@Mercedes-Guru]

Glad the vid could help. My Solex focus is very narrow, just for Mercedes of the 50's-60's. Sorry, but I have no other knowledge of the ADDHE. I Googled it and came up with lots of pics and info. Here is one link you might use: www.rmcarburetors.net/addhe_rebuilding%20v2.htm The ADDHE looks like a combination of Weber and Mikuni with a Solex name. I assume they borrowed from each other or purchased licensing rights to the designs. Best of luck.

[@fritzcamacho7092]

Do you rebuild or restore these carbs? I have a pair that needs rebuilding or cleaning. Do you have a way I can contact you?

[@Mercedes-Guru]

Hey Fritz, thanks for viewing and your question. While we are able to rebuild the carbs, we are desperately far behind in the shop. I would contact Just Carburetors [phone]. Tell Omar I sent you. Thanks, Will

[@fritzcamacho7092]

Thanks for replying back will, and also passing along a referral, thank you so much! I’ll reach out to Omar and see what he can do.

[@WoW_Lepic]

wow! Thank you again very much! It was very helpful. I tried yesterday before seeing this video to clean and check things in there. However there where 2 screws in each side I could not unscrew.. So, I 'll go today again with some extra tools and with what you sawed me, I will probably fix them. Randomly I saw the gas spray from the last two carbs and looked ok. I will the the other two today. I really hope that noone damaged those. I bought one of these synchronizers, so, one last question. What should I be seeing if I tuned them correctly?

[@Mercedes-Guru]

Which 2 screws?Use the syncrometer to get all the same readings thru all the throats. I have to assume your 4 cylinder is similar to the ones I work on, so you should see 8 or less on the synchrometer. This will depend on your normal idle speed and type of camshaft.The important thing is the readings are all the same. If not, check valve adjustment, compression, cylinder leakage, spark plug wire condition from cap to plug terminal, etc., normal tune-up things.Where are you located? I am in Dallas, Texas

[@WoW_Lepic]

I uploaded photos and a video in Google Drive. I circled which screws are stuck. One of them I managed to unscrew today by hammering it with a straight screwdriver. I think I might want to find new screws. Photo 1: drive.google.com/open?id=0B0enAjyv3soNbGh2V3VaQklrTHc Photo 2: drive.google.com/open?id=0B0enAjyv3soNdlZuMjNpcUctaG8 Video: drive.google.com/open?id=0B0enAjyv3soNRFJZSGlfLWNpOHM Sorry for the late responses but my schedule is weird. Should I screw harder the screws inside the cap I managed to unscrew?

[@Mercedes-Guru]

Normally KZbin alerts me of your comment. They did not so that is why I am late in responding. I had not heard from you and thought I better check.Thank you for the photos and video. They are big help.The blue screws need to come out so you can get inside the carburetor. The steel screws are corroded and stuck inside the aluminum carb body due to electrolysis. Use solvent like ATF and mineral spirits mixed together. Use heat from a hot air gun to expand the aluminum. Use an impact driver: kzbin.info/www/bejne/mYa2poaklLaNo82cttps://kzbin.info/www/bejne/hZiTqJyir7Knjrt2e careful. Do not break the screws.I saw the video. The problem with no idle is inside the carb. You have clogged fuel passages due to dirt or old fuel.Once inside use carburetor spray cleaner or similar volatile solvent to clean inside the carb.Report back on your progress. Where are you located?

[@WoW_Lepic]

Its ok about the responses, don't worry, my schedule keeps me busy well enough. I 'm from greece, and unfortunately mechanics here don't know carburetors very well and the ones that do, are not trustworthy. That is why I 'm searching for help on you tube and on the web. So, I got the synchrometer and the ratings are off in each carb. Also by turning the pilot ( idle mixture) screws I see no difference in the ratings. For example the could go from 5 to 4.9. The pilot jets where really clean and not moving (at least I think it was the pilot jets). Also I saw the gas sprayed in the carbs through the accelerator discharge nozzle, so I guess that works. I checked that only in the 2 carbs on the right. I cannot fit on the left ones. I will try to upload another video with things I checked and their condition. I have not checked yet the fuel filter. Also about what you said in around 8:40, I am not able to remove the pins with my hands, however they are loose.

[@WoW_Lepic]

I made a mistake there. About the idle mixture screws I ment that I cannot find where the engines stumbles. I see no difference turning these in or out.

[@spudmckenzie4959]

My idle mixture screws are sealed. There is no way to turn the screw to change the setting.

[@Mercedes-Guru]

That is very unusual. They have to be adjustable. Can you post a video of what you are dealing with and send me the link?

[@csedan510]

Sealed? Like how? No spring on the screw?

[@csedan510]

Nice info, looks like a manual from Todd Walrich (RIP) with his hand written notes in it.

[@Mercedes-Guru]

I think I talked to Todd some years ago. But, the manual is one I purchased new from Beth at Mikuni America many years ago and the notes are mine. Thanks for viewing and commenting. Will

[@byronmartinez8738]

what is the minimum fuel pressure for two 44mm

[@will4432]

Hello Byron, thank you for viewing and your question. Quoting from the Mikuni Service Manual “Fuel pressure of the fuel pump has a large bearing on the fuel level in the carburetor. The recommended fuel pressure is between 0.2 kg/cm2 - 0.35 kg/cm2, or 2.84 lb/in2 - 4.98 lb/in2.” Not mentioned is the carbs need adequate fuel flow, too. That quantity is not mentioned in the manual. But from other sources I have found “Output 35-40 liters/hour at a camshaft speed of 2500 rpm and feeding through a float needle valve of 2.0 diameter.” Hope this helps. Will