thanks sgt,

what type of jets are you using??????????

 

Hey crash, we get about 10 crank hp with head porting and valve job.
As Helix stated, hone the rocker arms out at least .0005"-.0015".
If you have time to pull the engine out and split the cases you can remove the lower vent tube. It goes right to the bottom of the sump and
makes the big bore's blow oil out the vent. (we are putting one together on Tuesday with the tube removed so I'll know for sure if it fixes the problem next week.
Hey Helix, I finished that new 400ex package we've been working on today. 48.7 rwhp
It hits 76mph on the dyno quicker then the white YFZ of Shawn's one from last year hit 64mph.
I'd like to run it through the timers next week if time permits.

 

Crashdog,you will be modifying those weights slightly for the big bore with cams,e-mail me on our website and I will explain.
The jetting will only be determined by the porting .pipes,airbox mods you have ..and can ONLY be PROPERLY set up by YOU and YOUR testing.

If you have the time,I would suggest sending the heads to Dynoray. He does the Best porting on a V-twin.I do not just think so,I KNOW so,from watching him trail and error many v-twins on the engine CRankshaft dyno that he has,and keep improving flow characteristics and angles etc for that particular engine. He has much experiance on flow benches ,aircraft engines and stock cars.I have seen customers come to his shop that he could not help,because someone had already ruined their heads and he did not want to waste their money.

Dynoray,I plan to test this DVX 600 some night,I'll call you we can make some passes on that EX.

 

Thanks Helix, I had a customer, Jeff, that has one of our 42rwhp 426 EX's at the shop yesterday after I took the 48rwhp EX off the dyno. He took it for a run and it blew his mind, LOL
His brother was there too that has a turner built YFZ 470 and he didn't think he would have anything for it, LOL
It won't run with the YFZ I built for Robert, but it's an awsom EX.
The big green monster (650 I built for Rick) should be done it's latest revision on Monday and should be in the high 70hp range as well as our new 767 Grizzly with Nos so Terry will be looking for some track time too.

Dynoray

 

Again, Helix is right about the jetting. I think we are running 182/178 mains in his but as we have found with these V twins each one is a little different as to how much air and fuel they want and you will have to test to find out what your engine wants. ie: a 650 we built this week ended up with 165/160 mains and one we built a few weeks ago, that was identical, wanted 174/172 with the same atmospheric conditions.
Dynoray

 

Crashdog,

I'm using Keihin jets and get them from Sudco. www.sudco.com. I believe they are the importers for the Keihin carbs, but I'm not sure.

Peace,
Sgt_Rock

 

Sgt Rock
Any dislikes on the 765 Kit?
What would you do different if you had to do it again?

I only have a few bolt-ons on my 02 650 Prairie and its difficult to keep the front end down on trails. I Need better brakes to fully enjoy my machine. I Can only IMAGINE what an extra 150cc 's does!!

Guess I'll wait till the "Brute Force" delivers and see how thew are running against the 765's and weigh my options

Happy trails

 

perhaps the dual piston calipers of the Brute Forces brakes will retro fit on the Prairies... this should offer much improved stopping power...

 

Anyone knows how much does Mickey Dunlap charge to port and flow the heads of a 700?

 

So far I don't have any dislikes with the BB Kit. If I did it over I would have Mickey do the install. I had a lot of build problems and expense because of an inexperienced builder. I would also consider a milder cam than Mickey's - i.e. Web or other. I don't know if a milder cam would be able to feed the big bore though. The FST cams are probably the most radical cams that could go in without excessive slap on the rocker arm pads. The FST cams have a borderline relationship with the rocker arm pads and you can hear them slap a bit at idle.

I'm looking to go on a dyno sometime this summer for a tuning session and will post the results. I can tell you that it is REALLY strong and contrary to what I've heard, there is no lack of bottom end or mid range with the kit. I don't recall where I read that someone felt there would be a loss of bottom end and mid range with the big bore kit - that's just not true. The torque is awesome.

Peace,
Sgt_Rock