Hi fellas I've just got my licence last week and finally can legally ride my bike ( 92  Fxstc) there's what I need advice on  I was riding home from work today sitting in 5th gear at 1600rpm and when i tryed to pull half throttle the bike was breaking down it was carrying like this for about 2kms until I hit the motorway then it came good I pulled the plugs when I got home and they seem fine not Carboned up or sooty  I replaced the plugs with new ones anyway took it for a ride and checked the plugs when I got home and they look good. What gear should I ride in doing 60kmhr I'm new to rideing Harley's so any help would be great. I've got an ev27 cam addjustable crane addjustable push rods big radius pipes and got a mate who worked at a hd work shop to jet the carb to suit  I hope some one can tell what was going on with the bike.

 

Did you let it warm up enough?

Yeah mate I make sure I warm it up for around 5-10 minutes before I ride it as I was told that evo's leak from the bore base gaskets if you do t warm them up before riding. My first thought was revs to low and fouled up the plugs but they look fine the rear was a little car ones up but that's normal I read.

5th gear @ 60km is too high which means your most likely lugging the engine.

4th would be a better choice...Normally I stay in 4th until about 80-90 and then click her into top gear (but I have taller gearing than stock)

Thanks tussuck I'm thinking that myself but I can't work out why it was breaking down like it was dropping spark in one cylinder. Anyway mate thanks for your reply I'll ride in 4th until 80-90 from now on and see if it does it again. 

How old is the fuel in your bike, you said you just got your licence so how long was the bike sitting around without getting used could be a build up of crap in the carby.

I would run a couple tanks of fuel through the bike and if the problem is still there then maybe give the carby a good clean out and see if that helps and btw good choice of bike go the Evo's cheers.

what tussuck said lugging evo or any Harley needs revs 2500 to 2800 rpm on the fly is there sweet spot (when warmed up) revs wont hurt lugging will and you don't need to give it 10 minutes to warm up a bit 2 to 3 min is fine with the choke off than don't rev the shit out of it for the first 5ks or so and being a 92 it probley has a
61 tooth rear pulley not 70 like the later

Thanks fellas fuel is new I've had the bike for over a year and replaced the fuel when I got my licence and I used to run it for 10 mins every two weeks while I couldn't ride it. Looks like my warm up will change to what youse have told me thanks heaps for the replies I'll keep youse up to date if if does it again. Thanks again.

At 50-60 k I'm in third.
It is a 4 speed though.

same same

Ok here's an update. I rode the bike for 80kms and pulled the plugs again and it's running lean I took the plugs to the lbs where's I buy my parts from and an older hog rider that was shopping there and asked him about my plugs and he told me that my bike is running way to lean and he also asked me what the bike has had done to it I told him it's got a heavy breather filter ev27 cam and big radious pipes. He told me to run a 45 pilot jet and that my 180 main is to big. Here's the problem I have now. With the 45 pilot jet the bike will idle fine but when I turn the mixture screw out from seated to all the way the idle doesn't change at all. What's going on here. I haven't rode it since I changed the jet. I hope someone can shed some light for me. I've tried spraying start ha bastard around the seal to check for vac leak but idle didn't change. If the jet was to big it would be running rich. When it was lean the carby had a 42 pilot jet which I put in when I changed the cam and it had a slight idle change turning the mixture screw but that's it. I hope yours can follow what I'm saying here. Help on this would be great. Thanks. I don't like paying shops if I can help it. I've built v8s and tuned them before but this has me stumped.

The carb has more to it then just a pilot and main jet needle height float level play a role as well. then with a cam your timing curve and or timing and voes if you have one will make a difference as well to how smooth it runs at certain rpms,.
If you want to get it somewhere close .
I usually start with a float level check then the old 4 position throttle plug chop.
Heres a few links . Just google plug chop or motorcycle carb tuning maybe even harley carb tuning it will give you an idea .
http://www.kawtriple.com/mraxl/carb/plugchop.htm
http://www.kawtriple.com/mraxl/carb/carbadj.htm

Independent 84 I have stock ignitio and set the timing to stock when I put the cam in does that make difference or should it be advance a little. As for the voes what is that. I Have no idea what that is and can that be adjusted. Thanks for the reply.

When for a ride and pulled the plugs with 2tur s out o. The mixture screw and now is running rich. Grr.

The mixture screw and or pilot jet only really effects idle and up to about 1/4 throttle then the neede height on the slide then the main jet at wide open throttle if that gives you an idea i really suggest you read into more before messing about though.Changing a cam without changing the timing curve is defeating the purpose imo. the voes is a vacuum operated electric switch wich can be used to changing the timing under different load conditions

It is going to be  time consuming and a bit of trial and error if you want your bike to perform at it's best. if it is all too much  it would be a good idea  to spend the money and go get it tuned properly by someone who has a clue .

 

Thanks I'm up trying to work it out at home I'll google the fuck out of it. I know I put a 30" spacer under the needle when I replaced the cam so I might have to remove that as well buy the looks of it.

Ok here's an update I was kicking around the shed and thought I should give the manifold a good hit with wd40 where it mates with the heads and you guessed it vacuum leak on the front seal so off with the manifold tonight good thing Ive new seal here I got in a lot buy with heaps of other gaskets and seals. I'll keep you updated tomorrow how it goes.

Good result....

I would stick with the 180 main. I run a 48 with a 190 and 2.5 turns out on the idle screw.

have you considered an s@s b or e carb?, they work really well on evo's with your bike set up and are very easy to tune and set up.

Those manifolds can be a bitch to get right.
I got some of these seals http://www.ebay.com/itm/GENUINE-JAMES-MANIFOLD-SEAL-TUNE-UP-KIT-FOR-HARLEY-SCREAMIN-EAGLE-44MM-INTAKES-/271304128281
for mine but i have a 44mm carb. Notice the extra lip on the blue seals though that mate against the head..