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Ok guys. Here is the issue, and I need help with it before Rooster has to come and put the fire out. He happens to be with the fire department here in our newly formed City.
I have for all intents and purposes a 79SF engine with a 2H7 TCI and the mechanical advance that is for the 79SF. I have the 3 ohm coils and there is no ballast resistor. I have the later carbs , the air box as well as the exhaust system, from an 81 MNS. I have been fighting with this thing for a very long time.
The story starts way back in November last year when I decided to finally get it running. I purchased new carb boots from Georgefix and installed them. That is where I made my first big mistake, among the many. Georgefix provides quality products so I have no beef with him. I did not know that when I installed these fine new boots that I did this to number 3 intake boot..
I then proceeded to triple clean the carbs, no dipping so don't go there. I set everything to factory specs for the 81MNS carbs. I went with factory recommended jets to start with. 42.5's in the pilot jets and went with 115 main jets. Set the float height to spec for the 81 carbs and tested them with the clear hose method for height and tested the needle valve for leakage. Bolted them on and tried it out.
No vacuum to set the synch with...damn. I then went in and set the valves to spec, thinking maybe they were out of whack. So now we have all valves set to spec, and re-checked. I then bought a dial indicator to set TDC on number 1. Set that . Set the Timing to spot on at this time as well to the specs for the 79SF. All should be good right? Nope it ran like **** acting too lean.
So I proceeded to set the carbs till the colortune said it would finally run a bit rich. 6 turns out seemed a bit much so I tore into the carbs and put in 45 pilot jets across all 4 carbs. Still needed 6 turns out. Re-jetted to 47.5's on all 4...needed 6 turns out to finally run rich.
That is the point when I found the intake leak on number 3 carb boot.
Fixed that up and WOW, now I have a bit of Vacuum, not a lot but enough to set the synch. Damn! Thinking that the Pilot jets had to be too rich now I set it back to the 42.5 pilot jets with the 115 main jets.
That did not work so good as it had the hanging idle as if it was running to lean. Checked the plugs and yes it appeared lean. Rechecked for vacuum leaks....fooled me once that did..
So I ran the idle/air jets out to when it would run rich. 5 turns now. Oh I am gaining on it right? Wrong!
I kept changing plugs as I no longer wanted to use the colortune, thinking maybe I was not reading it correctly. I had to finally get up to 47.5 pilots and 120 mains to get the plugs to have color. I get to the point when I have a light brown plug in number 2 and 3 at three turns out on the idle/air screws. Great I think I will just have to richen up number 1 and 4 to match and I will have a runner. Wrong!
I have to set number 1 and 4 to about 5 1/2 turns out to get any color on the plugs. Gee that just seems wrong to have such a difference to the ones on number 2 and 3 which are about 3 turns out. I think well maybe, as there is no set rule for carbs as to how far out the jets will be.
So I throw in a new set of plugs once again and run it. This is from a cold start using the enricher circuit which acts like it is flooding the bike. Get it to half choke which also seems to be flooding the bike. Get it to normal operating range so far as heat goes and it seems to run ok once I finally get the idle to the 1050-100 rpm range. Turn on the fan to keep engine cool. Run bike for 10 minutes or more at idle. Shut it down and look at plugs. They look like this with the idle/air jets set at #1- 5 1/2 turns out, #2-2 3/4 turns out, #3- 2 7/8 turns out, #4- 5 1/4 turns out.
So I shut the engine off and replace the plugs with new ones again. Start the warm engine with the idle screws set the same as above. Run it for ten or more minutes again at an idle. The Plugs have a very slight coloring to them, just a hint of golden brown to them. I have a pic in which i hope you can see the color. The plugs look like this.
So I think maybe the carbs can be that far out of adjustment to each other...no big deal. I then let everything cool off for a few hours. Try to start it. Acts like it is way too rich on the enricher again. Seems too rich on half choke as well. Run it for ten or more minutes and recheck the plugs. They are identical to the last pic which is ever so slightly golden brown, more of a yellow really.
During the start ups the bike will not idle properly . The bike acts as if it is way too rich on the enricher circuit. Then after a few minutes it starts to rev higher and higher. I have to then turn the idle way down or it will run at 2500 rpm. If I set it to 1050-1100 rpm it will not start right nor run for the first 5 to 10 minutes. It seems to stumble and cough as though I was pouring fuel into the carbs.
Now I do not know where I am at. Plugs look like a good color once warm and idling. Cold starts are totally sucking wind. Number of turns out on the screws seems whacky as does the larger size idle jets. Bike seems to run good, rev freely etc once it has ran long enough. Still way too much snow and cold here to ride it and see how it acts. New air filter, carbs cleaned and recleaned many many times, valves set, timing set, fat bright blue spark to all plugs, float heights checked, fuel level in carbs checked, new intake boots. You name it and I have tried to do something with it.
Sorry to be so long winded but maybe me writing this out will shed some light to myself or one of you as to what I may have done wrong and why the bike wont start properly. Thanks for listening to my ramblings. Any thoughts about this are appreciated.
I have for all intents and purposes a 79SF engine with a 2H7 TCI and the mechanical advance that is for the 79SF. I have the 3 ohm coils and there is no ballast resistor. I have the later carbs , the air box as well as the exhaust system, from an 81 MNS. I have been fighting with this thing for a very long time.
The story starts way back in November last year when I decided to finally get it running. I purchased new carb boots from Georgefix and installed them. That is where I made my first big mistake, among the many. Georgefix provides quality products so I have no beef with him. I did not know that when I installed these fine new boots that I did this to number 3 intake boot..
I then proceeded to triple clean the carbs, no dipping so don't go there. I set everything to factory specs for the 81MNS carbs. I went with factory recommended jets to start with. 42.5's in the pilot jets and went with 115 main jets. Set the float height to spec for the 81 carbs and tested them with the clear hose method for height and tested the needle valve for leakage. Bolted them on and tried it out.
No vacuum to set the synch with...damn. I then went in and set the valves to spec, thinking maybe they were out of whack. So now we have all valves set to spec, and re-checked. I then bought a dial indicator to set TDC on number 1. Set that . Set the Timing to spot on at this time as well to the specs for the 79SF. All should be good right? Nope it ran like **** acting too lean.
So I proceeded to set the carbs till the colortune said it would finally run a bit rich. 6 turns out seemed a bit much so I tore into the carbs and put in 45 pilot jets across all 4 carbs. Still needed 6 turns out. Re-jetted to 47.5's on all 4...needed 6 turns out to finally run rich.
That is the point when I found the intake leak on number 3 carb boot.
Fixed that up and WOW, now I have a bit of Vacuum, not a lot but enough to set the synch. Damn! Thinking that the Pilot jets had to be too rich now I set it back to the 42.5 pilot jets with the 115 main jets.
That did not work so good as it had the hanging idle as if it was running to lean. Checked the plugs and yes it appeared lean. Rechecked for vacuum leaks....fooled me once that did..
So I ran the idle/air jets out to when it would run rich. 5 turns now. Oh I am gaining on it right? Wrong!
I kept changing plugs as I no longer wanted to use the colortune, thinking maybe I was not reading it correctly. I had to finally get up to 47.5 pilots and 120 mains to get the plugs to have color. I get to the point when I have a light brown plug in number 2 and 3 at three turns out on the idle/air screws. Great I think I will just have to richen up number 1 and 4 to match and I will have a runner. Wrong!
I have to set number 1 and 4 to about 5 1/2 turns out to get any color on the plugs. Gee that just seems wrong to have such a difference to the ones on number 2 and 3 which are about 3 turns out. I think well maybe, as there is no set rule for carbs as to how far out the jets will be.
So I throw in a new set of plugs once again and run it. This is from a cold start using the enricher circuit which acts like it is flooding the bike. Get it to half choke which also seems to be flooding the bike. Get it to normal operating range so far as heat goes and it seems to run ok once I finally get the idle to the 1050-100 rpm range. Turn on the fan to keep engine cool. Run bike for 10 minutes or more at idle. Shut it down and look at plugs. They look like this with the idle/air jets set at #1- 5 1/2 turns out, #2-2 3/4 turns out, #3- 2 7/8 turns out, #4- 5 1/4 turns out.
So I shut the engine off and replace the plugs with new ones again. Start the warm engine with the idle screws set the same as above. Run it for ten or more minutes again at an idle. The Plugs have a very slight coloring to them, just a hint of golden brown to them. I have a pic in which i hope you can see the color. The plugs look like this.
So I think maybe the carbs can be that far out of adjustment to each other...no big deal. I then let everything cool off for a few hours. Try to start it. Acts like it is way too rich on the enricher again. Seems too rich on half choke as well. Run it for ten or more minutes and recheck the plugs. They are identical to the last pic which is ever so slightly golden brown, more of a yellow really.
During the start ups the bike will not idle properly . The bike acts as if it is way too rich on the enricher circuit. Then after a few minutes it starts to rev higher and higher. I have to then turn the idle way down or it will run at 2500 rpm. If I set it to 1050-1100 rpm it will not start right nor run for the first 5 to 10 minutes. It seems to stumble and cough as though I was pouring fuel into the carbs.
Now I do not know where I am at. Plugs look like a good color once warm and idling. Cold starts are totally sucking wind. Number of turns out on the screws seems whacky as does the larger size idle jets. Bike seems to run good, rev freely etc once it has ran long enough. Still way too much snow and cold here to ride it and see how it acts. New air filter, carbs cleaned and recleaned many many times, valves set, timing set, fat bright blue spark to all plugs, float heights checked, fuel level in carbs checked, new intake boots. You name it and I have tried to do something with it.
Sorry to be so long winded but maybe me writing this out will shed some light to myself or one of you as to what I may have done wrong and why the bike wont start properly. Thanks for listening to my ramblings. Any thoughts about this are appreciated.
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