sleeper06

#1 your down on compression might wanna re ring it while you have it apart and put s lil scratch on the cylinder so the new rings will seat. #2 I've gone .030 on pump with a rechamber might wanna check squish clearance now and report back before you start milling

Forgot to mention to ascetone all mating surfaces and reed blocks before glueing anything

Do yourself s favor take intake back off and use a thin film of 1211 or blk rtv , without a leakdown its peice of mind, put o- rings in with waterproof grease and they don't fall an get pinched or Vaseline

I hate when people post something and don't follow up

Zilla I'm not saying your bike didn't run good like that I've done about 25 2 into 1 builds and never came below a 185 main on any set up , perfect chops . Any build that was trail ported immediately jumped over 200 main

Did you get the dump n main sizes figured out , don't just bolt em up n go

Just spoke with these guys very nice conversation and I'll be buying a lot of parts through them

Mix 32:1 on premix 300 main 30 pilot one turn out on screw needle middle , this is ballpark what your compression at trying to see if you need that much octane

I don't see how that vent line on top of cool head would have gotten anything into cylinders , also when u buy something like a motor your at serious risk. Every motor add you ever see states low hours, fresh top end blah , blah. The fact that you have stock bore still raises a big flag to me, means someone slammed new Pistons in there and I'll bet u they are clearanced wrong and ring gaps are fucked. I have personally seen many fucked up ebay motors come through here, how much did you pay for it? I'll guarantee you still have all stock internals put back in and not a bit of care went into worn items. I build many motors from oem condition they usually take 1000-1500 in parts without labor . My suggestion is stop riding it leakdown test it first to establish good seals /o rings/gasket mating. Compression test to see where your at. Take off head check ring gap with a feeler guage you should have around.012 , I'm betting your off or there original Pistons that are shot

True dirty some people have a steady hand some don't , some should never put a grinder to anything. I have done many fix jobs in the past from people that thought "how hard can it be"

This is for dirtys comment, I never ruined a single set of cylinders when I started porting banshee shit , . I started porting outboard engines like 15yrs ago along with jet ski shit , only started messing with shee engines in 2006 heavy. A lot of my style is brought over from marine shit and works. Twin jet ski motors make 130-140 out the box with bolt ins . When I found out a shee motor made 36 I was like huh. To the op do research and aquire tooling my handpeices are well over a G. Raising shit across the board 1 mm really isn't the right way . Get a degree wheel set up and baseline the cylinder your working on. Read some books they will give you general timings to work off or hit me up in a pm and I'll help you out just like I was helped out when i started

One of my drag ported Cubs dialed in at 122.5 dumps /mains,55 pilot ee series needle 2 nd clip. Modified pilot circuit , one float cut off , big ass bowls . Now this is a 1/4 mile bike I would def call hjr to see how he would set it up

39 pwk ,is the 421 drag ported and what type of racing do u do, it will depend how I would set carbs up

I went to a drag about 6 yrs ago and saw s few people in s stock class run t-5 silencers on a stock bike stock class with some crazy intake cones behind the carbs , they ran petty great

I try n turn away half ass people . usually the porting is the cheap part in the grand scheme , it's everything to support the hp that's expensive

That measurement is fairly common give or take,never just throw Pistons in the should be measured and clearances properly even if it just takes a hone. The machine shop that does all my work has a wiseco sizing book and can give you an answer on piston size with consideration to roundness of bore etc. moral of story never just throw anything in if you want it to live

Just being ported is hard enouph give the crank some tlc

Last one I put together was with 70 mm wsm pistons it sat .005 below deck with .020 base , a lot of the old 370 shit I have seen has been decked some on the bottom side cylinders

Take your measurements send head to mull engineering,have him cut it for alky, l like stock cyl between .045-.050 squish

50:1 is playing with fire literally no need . Make sure u pressure test it before you turn a nut otherwise your guessing , then compression test it, see if you smoked the rings, if you smoked the rings make sure you didn't collapse the skirts and check the cylinder for round

Like I said some good some bad, communication wasn't great but he's a kid didn't expect much

Because of people like this I pressure test n compression test everything that comes through door before I even kick the motor

I had them build me a crank for a customers bike , I asked about 10 ball in the middle . He explained there center sections were thicker then stock and they use a special 8 ball for that so there's a lil flex in the center. I've never personally seen a center bearing go . Seen plenty wear with tons of runout but never break apart. In my head I can't grasp the whole flexing idea but I'm sure they have tons of r&ad

N2o what size is that stuff

He won't just sell the webs neither will tdr, crank works will but they want 800 , I've used wsm parts for yrs without any problems or failures but assembly and overall package is key. I just put a 4 mil Vito's crank in a members bike I was actually impressed with it. I put good bearings on it and he likes it , and if anyone will break it he will so we'll see