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Help I can't ID the carb on my 76 ironhead-------------all it says is AMF Harley Davidson Japan ---any ideas and if so how to adjust-If it says Japan does it have to be a Kehin?????????????????????????????????/
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1. Removing it from the bike should be straight forward. First thing when it is out is to check the pilot screw setting. Turn it all the way in until gently seated counting the number of 1/4 turns; then write this number down; then reset it.
2. I put mine in a vice to remove the screws, and for much of the following work. Wrap in a shop towel; close the vice gently taking extra care with the choke and throttle linkages. The vice is a needed extra pair of hands.
3. You must be very careful handling the float so as to not change the level. You must have the official specs for setting the level as in the FM, and check it, every time you dismantle the carb, as the last thing before putting it back together.
4. The jets are made of brass, a soft metal that is easily damaged. Use an exact correct size screwdriver. I ground a medium flat blade screwdriver down to exact size on my bench grinder to access the slow jet.
5. The general appearance of the inside of the carb is not necessarily a good indication of its condition. It can look spotless and have clogged jets, or look cruddy and have clear jets.
6. Ignore any advice that says to soak or boil the whole carb in carb cleaner. Rather, clean each individual part. Do not allow any solvents to contact any rubber parts [tip of needle, o-ring seal for bowl]
7. Make a list of all of the jets and passages for your carb using the carb manual or the FM for the bike. Then ensure that you can blow either compressed air or carb cleaner thru each one.
8. Remove the pilot screw and clean the parts and the passage. The passage contains in this sequence: pilot screw, spring, washer, o-ring. These are very small parts, especially the washer and o-ring. Usually the spring will easily fall out. One time i thought the spring was not in there because it would not fall out; i obtained a new spring and could not get it in! The technique for removing the washer and o-ring is to use a pipe cleaner: stick it in the hole, twist it around, remove it - you should see the washer and o-ring on the end of the pipe cleaner.
Remember that the purpose of the washer is to protect the o-ring from the spring and you will always get them back in in the correct sequence.
9. Dismantle the accelerator pump assembly noting carefully the sequence and orientation of the parts. Clean and inspect the parts. Replace the diaphragm if it is cracked.
10. Check the float level then carefully put it back together. I personally find it very confusing trying to decide which way to bend the tang if it is not correct. If the fuel level is low is the float high or low? Do i need to bend the tang up or down? On the bench the carb is usually upside down, adding to the confusion. Sort all this out before making an adjustment.
Best to replace the original Phillips screws for the bowl with stainless steel socket head screws.
And my notes on setting the pilot screw ...
Setting The Pilot Screw on Your IronHead
If the carb is old and dirty the pilot screw passage may be gummed up such that you will not be able to "gently seat" the pilot screw reliably. If this is the case remove the carb from the bike and clean it up. Some guys try to do carb work with the carb in the bike. IMO this is a very bad idea.
In the pilot screw passage there should be, in this sequence: screw, spring, washer, o-ring. [Often POs have installed these parts in the wrong sequence; remember that the purpose of the washer is to protect the o-ring from being damaged by the spring]. The screw usually comes out easily. The other parts may require some work. The best technique is to stick a pipe cleaner in the hole, twist it around, and, like magic, out come the other parts on the end of the pipe cleaner.
1. You need to have easy access to the pilot screw, easy enough to reliably judge "screw it in until gently seated". Loosen the front fuel tank mount bolt; remove the rear fuel tank mount bolt; prop the rear of the fuel tank up on a piece of 2X4; on some bikes this will not be necessary.
2. With the engine cold [so you do not burn your fingers] turn the pilot screw in clockwise until it is gently seated. Count the number of 1/4 turns as you do it; write the number down. Back it out to the original setting. You may need to return reliably to this setting after experimenting.
The "normal" starting point for this process is 1,1/4 [according to the 79 - 85 FM] or 1,1/2 [according to usual practice] turns out.
NOTE: An old magazine article recommends for Keihin butterfly carbs between 1/4 and 1,1/4 turns out. My experience is that this works best. If you are more than 1,1/4 turns out your pilot jet is too small.
3. The engine must be at full warm up. It will have very hot parts; to avoid burned fingers have a well lighted, comfy place to work.
4. Set the engine idling at about 1000 RPM. You want it to be idling at the slowest speed that is consistent with a smooth idle so that you can hear or feel slight changes.
5. Turn the pilot screw in clockwise until the engine idle becomes worse; tending to stall. Count the number of 1/4 turns as you do this. Then turn the pilot screw out counter clockwise until the engine idle gets good, then becomes worse, tending to stall. Count the number of 1/4 turns as you do this.
6. The best setting for your bike will be somewhere between these two settings. The FM says to use the leanest setting [most screwed in] consistent with a good idle quality. Some guys say to go between the two settings.
It should be between 3/4 and 2,3/4 [preferable between 1 and 2,1/2] turns out from gently seated. If it is not within this range you should change the slow jet.
7. You may have to adjust the idle speed.
8. Make sure that the spark plugs are clean, then ride the bike around your neighborhood for 10 minutes. Keep it under about 10 MPH so that you are on the "idle port", not the "idle transfer ports", the "mid range port", or the "main jet" [see carb diagrams in FM]. Hopefully the plugs will come out a nice medium gray or tan color. If they are too dark you can screw it in another 1/4 turn; too light screw it out 1/4 turn, and try the ride again.
9. If they are really light or really dark the problem is not with the pilot screw setting. For example, too light might mean an exhaust leak, and too dark might mean the pilot jet is too large [among other possibilities].
10. My experience with this process is that after making a change i have to clean the plugs and go for a good ride [say, an hour or more] before i can trust that the new results are reliable.
any tips on adjustments? went for a ride the other day, ran kind of bad then all of a sudden, ran perfectly out of the blue except idled real fast. Checked plugs @ home and they were all carboned up, plus bike seemed hot-need adj. tips------got any?
no the carb is just out of wack, could be dirty air filter, pretty bad, but think carb is out of wack, maybe too rich, know how to adj easily????????????????????
one more thing, I've asked 10 people and shops what kind of oil to run and got 10 different answers-took the one who said Harley 60 weight-right? or wrong?
Look at the last half of Ironmick's post for idle screw adjustment - that will affect not only your idle mixture, but mid-range mixture, too. Other than that, changing jets are about the only adjustment possible. Is your air cleaner really dirty? That will make it run rich. As far as oil goes, 60wt is fine in hot weather. If it's below 80 DegF sometimes, I'd use 50wt. In the winter, I use 20W50.
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If it ain't broke, don't fix it.
Help I can't ID the carb on my 76 ironhead-------------all it says is AMF Harley Davidson Japan ---any ideas and if so how to adjust-If it says Japan does it have to be a Kehin?????????????????????????????????/
If you think you have a Kehin carb I have some info on the CV40 Kehin that may (or may not) help you out.
I cannot vouch for this info myself and it is written something like 'Carb Tuning For Dummies', and in fact I cannot say if the guy even explains the tuning function. It does have pics and call outs of the different Kehin carb parts though.
But, if you want a copy you will have to email me, tell me you want the Kehin info, and I will send it to you............. wb_perry@yahoo.com
It is in PDF form, so I cannot post it here on the forum............. pg
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Rolling down the highway on two wheels since 1957...
Owner Red/White 1971 XLCH & 2003 FXDL-Silver over Black
one more glitch in an old bike
Help I can't ID the carb on my 76 ironhead-------------all it says is AMF Harley Davidson Japan ---any ideas and if so how to adjust-If it says Japan does it have to be a Kehin?????????????????????????????????/
