Going with 95", having my jugs bored and putting a set 0f se 10-5.1 forged domed pistons. Heads are getting ported and polished, bigger valves, valve springs and compression releases. Going with 10.3 comp. Putting a HQ- 575 cam in the old girl. tearing her down tonight, just waiting on the pistons to come in to get the ball rolling. The guy doing the work says he wants the pistons before he will bore the jugs and set the heads up for the compression and cams. Where would you guys start with jetting on the carb. got a jet kit off of HQ. 46 slow, 195,200 main and a differant needle with a shim. I'm curruntly running a 48 slow, stock main and a shimmed sporty needle. Last question, What ignition would be best and easiest to use?

 

If you have not yet, ordered those pistons, no reason not to go to 98".
Scott

 

DTT TC88, start with 2/4 dial settings and go from there. If you want to play, get the USB cables and you can make changes but the dial settings pretty much cover the bases.

 

Guy doing my heads has a new crane ignition with the cord and software for my bike. Only wants 180 for it, Gotta go with it, Thats a steal. My buddy who is helping me with the build and the guy doing the head work are telling me I should go with a 42mm carb. I hate the thought of switching to a mikuni, I know nothing about tuning them.

 

With ported heads and 1.9" intake and intake lift of .575" the Mik42 will show a difference in HP, maybe 5, above 4500rpms; maybe a bit below but not much. The thing is, you need the carb to flow as much as the heads, so if the heads flow 160cfm (10") then the carb should be capable of flowing the same. As important as the carb is the intake manifold and the air filter.

DaVinci is one company that will bore your CV to 42mm and make other modifications good for an additional 10-15HP fo about $275, IIRC. Forget what a Mik42 cost but IIRC, about $400? maybe some better deals on Ebay? So don't know if modifying the CV makes sense $$$ but that's where I would be looking. Woods modified Keihin carbs are a bit pricey but the flow is better and his mods to improve the carb; better mileage and fuel flow but don't know if that's justification for the cost; a personal choice.

It would be a tough call for me, I like the CV carb, know how to tune it and don't like the Mikuni slide rattle and would have to learn how to tune the Mik.

 

I would rather have cv reworked, Going to rejet and go from their. He does flow the heads, I'll have the numbers, could be done by the end of this week. Pistons came today so the jugs can be bored. Might be able to put her back together some time next week.

 

We are of like minds. I think the CV40mm will be close but, without modicication, could be a botteneck at WOT and in the upper rpm ranges depending on the capability of the heads. Good luck!

 

A CV carb, with a Stage 7 Thunderslide kit, coupled to a spigot-style, S&S manifold(as long as the 1.780" manifold will mate correctly to the heads) will be the most cost-effective route, from what we've seen here.
Scott