Alright 1st post and a first for me since I have never seen or heard of this issue which brought me here. ok so i have a pretty freshly built 1974 sportster xlch 1000. Im goin to start from the beginning of my problems so it is going to be a long story. Last year mid summer i was riding the old girl throught town stop and go traffic. about 3/4 mile between the stoplights i hit. was waiting for the light to change when the bike shut off. this was i think where problems may have started but highly doubt it since the idle was not set right and it would die if i let it sit in gear. got the bike started took a few kicks but it started just as normal. rode it about a mile parked shut it off to check directions and went to start it and it refused to. must of been leaking oil out of the crank case breather because there were quite a few drops littering the area i was stopped in due to it being a kick over bike. (good thing im young i guess) i eventually got it started but it kept on dying on me till i finally got on it and started moving and then it died about 30 feet away. i gave up after that as it was about 80+ that day. got it back home and did a compression check. noticed the front cylinder was about 30 psi under the rear cylinder. took the head off and had the head checked. head was fine. the pistons and cylinders are brand new. maybe had about 500 miles on it so just about done with break in. threw the bike back together and got heat running through it and redid the compression this time it was spot on. cant remember the psi but i remember it being very healthy. the ratio should be something like 10.5 .1. i readjusted the pushrods. cant even tell you how many times ive done that. but now it has decided to be cranky when giving it gas. i can get it to idle just fine but once i give it gas about 2500rpm it starts to break up and back fire. no matter what adjustment i do on the ancient tillotson it doesnt seem to work. ive looked over the diaphram and it does not look like it has any holes in it. ive noticed there is gas comming out of the bleeder and the accelerator needle when i give it gas. could it just be the carb or something on the lower end that could have done something when i last rode it. also the entire motor was overhauled new aftermarket cams, wiseco forged pistons, and chopped up flywheels. could something have messed up the timing.

 

I'm assuming you're getting good fire. .. it sounds like it's just flooding out cuz issue with carb. Float stuck maybe. ..I'd also wonder if you don't have a tank vent problem to. ..just guess tho....u really need to go to classic section and then to the Ironhead section and repost question.They will be the guys that can help u for sure.

 

Take this question to the ironhead section. I'll see if I can help for the moment. I have a 75 XLH and Bendix was the stock carb back then. I may be wrong but I believe they dumped Tillotsen years before that. Either way, you are much better off to get a 38mm mikuni or at least anything other than a Tillotsen or Bendix. It sort of sounds like that carb is shot and not operating at all right. The Bendix has an accelerator pump and if it isn't working will run like yours is running.

I think you may have had a pushrod too long as well. Loss of compression kind of points to that. The rear exhaust pushrod on my bike seems to be the most problematic. You might have a cam off a tooth but I doubt it.

Lastly, the intake manifold is really hard to get set correctly without any leaks. You might look there for a bad air leak.

Carl

 

Breaking up under acceleration...intake manifold leaks or bad plugs. Solid lifters, so you should barely be able to spin the pushrods in your fingers when all the way down.
Beyond that, check your points, condensor, and/or timing.

 

Or the Tillotsen. Without being there and seeing first hand, if your manifold isn't leaking and the plugs aren't fouled, get a Super E on that Ironhead.

 

i checked the push rods and they look perfectly fine. I want to upgrade to a super e but then i wont have a tach guage as i have points and the big float bowl gets in the way of the cable. the tillotson i have on it was rebuilt last year along with the motor. new accelerator pump and springs. i did notice that fuel was comming out of the bleeder valve and the accelerator pump when i rev it. i ordered a new pump diaphram for the carb so hopefully that fixes it. I am really hoping one of the cams did not jump a tooth. it sounds perfectly healthy idling it just once i give it any gas. and i spent a good hour trying to get the intake to seal good but i now have everything in place perfectly i noticed the first time i put it on that the rubber o rings were not seated correctly and i thought that might be my problem but its still doing it.

 

i would love to get a super e but i need to ditch the points before i can since i only have the cable comming out of the points to measure my speed/revs

 

tried two seperate sets of plugs and it didnt change. i checked my intake and it doesnt seem to leak, before i didnt have the o rings set properly and i thought that was the problem but it wasnt. points and condensor looked fine no over spark or anything out of the ordinary.

 

I'm really trying to understand what your problem is, but I can't figure what the heck having points has to do with anything. Where your tach cable connects shouldn't keep you from running any type of carb. I had a "72, '76 and '77 XLCHs and all had points, tach and S&S carbs.

 

the timing case i have makes the points come out directly under the carb so there is not enough room to fit a tach cable in it with the float bowl. i got the new carb parts in and it does sound a little healthier but i really need to figure out how to tune a carb. its still running way rich.