And away she goes...first real start.

[Revvy Kevvy]

Today I started her up for the first time. I have rebuilt the carburetta, rewired part of the ignition, cleaned and replaced the points and made a petrol (gasoline) delivery system. I also connected my new vacuum gauge that is supposed to help me tune the carburettas.

After 25 years of sleeping she can actually start and idle. Not very well but she can.

She will only start and idle in full choke or half choke. The video attached is her idling in half choke. If I turn off the choke she stops. My vacuum gauge is not really very helpful
I tried turning the screws on the top of the carburettor fully out, fully in but it don't change nothing and eventually the battery went flat so I stopped. Plus, I got a headache from doing this inside a small room...probably got carbon monoxide poisoning.

I guess I have to tune the carburettas somehow but I am only aware of the screws on the top (I understand control the mixture) and the idle screw...

Anyway, after 25 years of being covered in bird shit and being abandoned in a barn in northern Sweden, today she actually started and at least idled for 10 minutes.

I need to think of a name for her, my last GF was a serious pain in the ass but the one before that was nice and cool so I am waiting to understand to call her Katia or Yulia. I need to determine her personality first. But, as far as a sleeping beauty is concerned I guess I am the first to kiss her after her 1/4 century slumber.

Seems you cannot attach videos, even 10 second ones. Anyway, she is idling with the vacuum meter going crazy left and right (where you usually attach it, I have mine on the little plugs on the rubber boots inlet of carburetta) She idles at half choke but cannot idle at normal. She wont start in anything but full choke, I dont know how long you would normally let them idle for at half choke before switch to no choke.? 1 min? (no air filters attached)

 

[Revvy Kevvy]

Maybe the float level is too low? would that make it run rich? Cause I can really smell it. It reminds me of grandpa's old studebaker running on full choke warming up on a cold morning.

 

[CaptChrome]

Having the fuel level set properly is pretty important to getting the mixture correct. I think you will have to look at everything on the carbs one-by-one and checking how things improve or not. I feel that tuning the carbs is really the most important aspect of getting a bike to run correctly and is the part that most people just rush through. This might take a while.

Regarding warming up the bike with the enricher, mine needs to run at ½ choke for about two km for me to push the choke off. I guess that might equate to five minutes from the time I start the engine to when I don't need the enrichment anymore to get a stable idle. Also, if you are idling on ½ choke, the idle speed should rise (like starting from 1250 and then rising to over 2000 rpm) after the engine warms, so that would be a good indication to you to turn the choke off.

 

[Revvy Kevvy]

Having the fuel level set properly is pretty important to getting the mixture correct. I think you will have to look at everything on the carbs one-by-one and checking how things improve or not. I feel that tuning the carbs is really the most important aspect of getting a bike to run correctly and is the part that most people just rush through. This might take a while.

Regarding warming up the bike with the enricher, mine needs to run at ½ choke for about two km for me to push the choke off. I guess that might equate to five minutes from the time I start the engine to when I don't need the enrichment anymore to get a stable idle. Also, if you are idling on ½ choke, the idle speed should rise (like starting from 1250 and then rising to over 2000 rpm) after the engine warms, so that would be a good indication to you to turn the choke off.

Yes, nice observation. My feeling is I don't have the carburettors set correct yet. I feel fairly confidant with the timing and the spark looks good, nice and thick but I dont think I have got the carburettors set up good.
I tried plugging in a vacuum gauge but its all over the shop so either I bought too cheap one or I dont know how to use it yet. My next plan is to remove the carburettors and give them a good look over. I am fairly sure I have the floats set all wrong as the fuel does not seem high enough to me. Damn she is running rich too, like really rich.
So, tonight I will pull the carburettors off again. Not too difficult since I bought new rubber boots and look them over again. Set the floats again and then try and try again. I have a week before I am out on business again so that can equate to a few attempts. Thaks for the words of encouragement, hope we ride together oneday although I guess you are in the USA so its gunna need some setting up.

 

[Revvy Kevvy]

Off the carbs come again and looked them over. If I do the test in the manual with the tubes connected to the drains then it all looks wrong. For some reason the only way I can get it right is to set it to 20mm but I found a few youtube tutorials that suggest 20mm for example

In the haynes its suggested 32mm, in the yamaha manual suggested 27mm in various youtubes I get other suggestions. In the end I went with 20mm as that got the petrol up to the top of the bowl when the clear tube is attached to the drain underneath.

Whatever is the small hole on the front of the carburettas as shown in the picture below, I cannot find where it comes out.

In the end I fell I dont really like these carburettas. I was very familiar with typical downdraft type as fitted to most cars with jets and pump jets. I feel these mikoni are overly complex and have jets that I cannot work out where they go. I might develop a appreciation for them but at the moment I dont feel I like them.

I stopped working in the garage for today, its so bloody cold in there!!