| Author | Message | ||
     Robertb1958 |
Sort of by accident, I have both an '96 S1 and '00 X1. My S1 is a little jealous of the extra zip that the X1 has at higher RPM's with the stock FI Thunderstorm engine enhanced with "race" map. So, I am planning to do a low budget (I hope) S1 engine upgrade. Last year, I got a good deal on a set of 2004 Sportster heads. Just got a set of XB12 pistons and cylinders that appear to be good. Planning on new rings, and a light hone refresh of the jugs, and basic valve job to be sure all is good. Will check the oil pump drive gears while in there. I am thinking this setup should put me at least at S1W performance. The Keihin is still on the S1, supposedly with the dynojet kit. Bike has a V&H muffler and Forcewinder filter intake. What else should I do on this budget build? Yes, I know head porting, hotter cams, and maybe an HSR42 would be good, but not this year. What jetting was in the S1W? Acceleration is a little "uneven" right now, so I am thinking that I should sort the carb before doing the build. | ||
| Buelliedan |
the new top end should get you real close to the X1s power. The new heads are 1200 heads not 883 right? | ||
| Robertb1958 |
Yes, part number is for 2004 1200 heads, thanks for the heads up, Buelliedan. Just took the S1 out for a spirited ride. It is somewhat breaking up above 5K RPM, think I should sort this before the rebuild, for sure. My impression is that it is lean. | ||
| Phelan |
Should be a good build. Don't forget the new front mount to fit the later heads. And a carb rebuild kit as they are cheap. | ||
| Dannybuell |
Forget the heads, get a mikuni and a dyno tune! I did the kehein dyno jet... A Mikuni/dyno tune is the way to go! Save your money for a Baker 6 speed. my 96s1 has 105,000 miles. | ||
| Figorvonbuellingham |
The kehien has a screw blocked off. You can drill out the block off plate and get some more tune there. I can't describe where it is but maybe some google could get you on the right track. Its been about 25 your ars since I did one but I remember it worked great. The Harley dealer thought I had installed hot cams and were threatening to void my warranty. | ||
| Dannybuell |
The kehein is a governor, plain and simple. A mikuni dyno tune on a fresh engine with a Crane S&S adjustable nose cone ignition and that dog will hunt! these changes alone will move your kehein couch potato S1 into athlete status. | ||
| Phelan |
He already has the heads and pistons/cylinders. Personally I would put these on first (don't forget a front mount and gasket kit), then sell the stock heads and jugs and put that towards a Mikuni afterward. You already have N4 cams so the heads and pistons will net you a better gain than the Mikuni alone. The Mikuni is well worth its price in throttle response but it won't give you as much power as the bigger valves, squish area, and ports. | ||
| Imadog |
Does the Mikuni make that much difference in power other then the throttle response? My Keihin really seems to do a good job and my riding style, and roads don't really let me whack the throttle WFO. With all the torque I find it easier to go fast by having a smooth throttle hand. | ||
| Robertb1958 |
All, thanks for the input. If I can't sort the Keihin before the build, I might scrounge up some $'s for the Mikuni. The high RPM "breaking up" seems like a lean condition to me, but it could be ignition. I have learned the hard way to get support systems sorted and working before making major changes. | ||
| Oopezoo |
Curious about what was done to the carb when the jet kit was installed. My S1 had an aftermarket pipe and intake on it, but the carb was never touched. It felt like it was running hot to me and there was a lot of popping and bucking when I snapped the throttle shut (typically a lean condition) I ended up changing the jets to whatever numbers I found searching here, and then seated the mixture screw and backed it out 2.5 turns. It ran fantastic after that. Like a completely different bike. I'm wondering if your jet kit was installed without the mixture screw being adjusted. Its worth a look and can be done without removing the carb from the bike. | ||
| Imadog |
I forgot to mention, I did make the changes to the carb as well as the carb intake seals and gaskets recommended on this site. #45 idle, #200 (already installed)idle screw 2-3/4 turns out. These changes made a world of difference. See my profile, only thing I did not do was drill out the slide. I just picked up my 2nd M2 recently and just got the bits and pieces in this week. Good Luck! Here is another recent post on the Keihin: http://www.badweatherbikers.com/buell/messages/476 23/760088.html?1429282228 |
