| Author | Message | ||
     Buellsrule |
Anyone have a 1250? I'll be keeping the FI now that I've found a way to tune it. Valve size? Cams? Compression? Please describe as best as you can. Thanks. BR. | ||
| Brokeneck |
I thought when I last talked to NRHS about 1250 conversion -- they directed me towards headwork but thought the stock FI would not support the 1250 conversion -- maybe my memory is wrong or my hearing was bad after 3 Dyno Runs -- | ||
| Buellsrule |
Terry Reed racing out of Columbus, OH knows how to tune with the Directlink system. He's tuned an 88" xb and says it should have no problem with the tuber. | ||
| Dfbutler |
I had to get my engine rebuilt because of failed rod bearings over a year ago and decided that I would go with the 1250 kit: http://www.revperf.com/XL/xlPerform1200.html I already had the race ECM installed and changed nothing and the engine runs great | ||
| Werewulf |
i hear everyone talking about the 1250 kit.. does it really make a substantial improvement? 50 cc doesnt sound like much.. | ||
| Bartimus |
It's not so much the cc's that do the trick, but the cams and the head work... I have a 1250 kit from NRHS in my '95 S2, it has about 104RWHP now, quite an improvement over stock. It's a total package that really brings your motor alive, just doing one or two things won't really give you the performance you are probably looking for. | ||
| Dfbutler |
First, remember that the most expensive and time consuming component is splitting the cases, adding some displacement is a good increment. Also there is an increase in compression from 10 to 10.5, which will generate more power. | ||
| Cyclonemduece |
you have to split the cases to do a 1250? if that is true why stop there go 88" | ||
| Bad_karma |
Frank I'm running a zippers kit. Check it out. I'm carbureted but I believe that your remapped FI should be able to handle the fueling requirements. You do not need to split the cases. The compression is just below 10.5:1. I'm running redshift 585's but don't recommended them unless you are going to spend sometime in the upper rpm band, I love them in my S1. Make sure to upgrade your lifters and I recommend roller rockers. If finances aren't an issue look at zippers 88" kit in the torque mode. If you decide to stay with the 1250 consider balancing the assembly(this will require splitting the cases).Also the 1250/head mods will work best with freer flowing intake assemblies and exhaust. Joe (Message edited by Bad_karma on February 05, 2008) | ||
| Dfbutler |
It is my understanding that anything over 1250 requires machining the case, same with going with more aggressive cams. | ||
| Oldog |
Donald: case machining is for either clearing the spigots on the bottom of over size jugs on real big bores the jugs spigots must be cut as well or relieving lifter bosses for high lift cams AFAIK | ||
| Bluzm2 |
Blake, No case splitting required for a 1250 kit. Just bolt the bugger on. (after checking clearance etc..) Brad | ||
| Bobo |
I did the NHRS 1250 on my 06 sportster with stage 2 and SE 575 cams with a 15 degree squish. Haven't been to the dyno yet but I will do this with the X1 too. It will just have to wait its turn. While the sporty is carbed I see no problem remapping the FI and assume I may do better than with my modified HRS42. We'll see. |
