I'm fairly new to motorcycles and just bought myself a Harley Sportster lastsummer. The bike is a 2001 and the previous owner had put a lot of work intothe bike. From what he told me it has SE racing cams, SE ignition module,K&N, straight pipes...blah blah..you get it, he hopped it up.

So, last year the ignition module went out and was replaced by a stock Harleyone. The bike ran great for about 5 months but just recently had to go backinto the shop due to it fouling out plugs and running poorly. This was really odd because I had rode thebike 2 weeks earlier and it was fine. It’skept in a garage so it wasn’t sitting in the elements.

After the ignition module was swapped for the stock Harley one, I did noticethe bike seem to lose a little power. I was ok with it because I figured it wasdue to the stock part vs. the SE part and it still had some good get up and goleft in it.

Fast forward 5 months to today - I Just got the bike back from Harley and itagain seems to have lost some power. It runs good but I feel it’s not as fastoff the line as it used to be. They rejetted the carb from 45 slow to 42 slowand 180 main to 155 main. The slow seemslike a small jump but the main seems like a huge jump.

My question is:
Is it to be expected that I'd lose some power or did the tech just jet thebike back down to "safe" setting and disregard my upgrades? Should I be questioning his work?

 

Did you check your sparkplug color before having work done? 42/155 is too small if you have upgraded pipes, cams, aircleaner, etc. 45/180 sounds about right to me.

Check your plugs, they are probably showing a lean condition now. There was no reason for him to touch your jetting, I'd ask him, WTF?

Also, check your throttle cable to see if you get wide open throttle, that might be part of the problem.

John

 

+1 - Not even a stock 883 comes with 155 main, that's way too small.
BTW - what motor, 883 or 1200?

 

I was just looking through the old service receipts trying to figure outwhat was installed and came across this information on the bike.

883 converted to HI-PO 1200 kit
Buell heads and Rings
SE 25 Cams
Thunderslide kit
SE ignition and wires (now stock Harley ignition)
K&N air filter

The plugs were fouling out within 5 min of starting the bike.

What I did before I took it to the shop:

Cleaned K&N
Drained tank and checked/cleaned fuel filter
replaced vacuum line going to petcock
replaced spark plugs and gapped to .30 ( that’s what the old ones weregapped at)

 

Under what conditions? Sitting with the enrichener pulled out? And it ran fine for you before taking it in?

If it ran well before they changed the jets, then that is the obvious place to start. The original jetting sounds fine, but I'm not familiar with the Thunderslide and if your slide needle may need adjustment. You need to return it to how it was and then assess your spark plug condition. With a carbed bike, that's your best indicator of jetting.

John

 

I'ld say your choke cable needs replacing. My guess is its not staying in after starting.
How long do you have the choke on after starting?

 

Quote:

Originally Posted by John Harper

Under what conditions? Sitting with the enrichener pulled out? And it ran fine for you before taking it in?

It wouldn't stay running without the enrichener out all the way... I even tried to warm the bike up holding the throttle at about 2500 rpm with the enrichener off but would stall out as soon as I put it in and let the bike idle. I'd check the plugs and they would be fouled out. I pulled them and cleaned them but got the same results. After trying everything mentioned above I decided it was out of my hands. I'm just worried that having the bike jetted the way it is, my performance parts are not being utilized to the fullest.

 

A 155 main on a c.v. with that combo! Holy smokes! That is danger zone!!!!!!!! My gosh....ludicrous

 

What are 25 cams? 497S, 536s or 575s

 

That's what was printed on the service slip when they did the install. All I know is the last owner said they were screaming eagle racing cams.


Danger zone??? what do you mean?