sleeper06

Did you change the oring on the seat brass barrel? Are your reeds sealing or letting pressure back in? You can stop playing with jetting doubt that's it , but you are in need of a top end

I've welded a ton of cylinders and cases , I would still say epoxy it , I've seen machine shops weld cylinders and actually make the cast porous . When I pressure tested the machine it bubbled rite out of the aluminum pores

Use a washer to space nut to good threads

I can try n tig it but I think you're creating a bigger problem depending on how thin the wall is before you bite in

I always use marine-tek grey , it's good with all fuels . Clean area with carbide burr everywhere, wash with hot soapy , wipe with ascetone . Then rite before I I'm ready to apply I heat area up with a heat gun to open pores and apply

#1 wiseco crank #2 Dave built it #3 Dave built it #4 Dave built it On the other hand they do keep me busy!

If the clutch is slipping it won't shift either

Granted you might find cheaper stuff on eBay , but I can pick up a phone and speak with someone that's has knowledge of the tools and platforms I deal with from various marine stuff to four strokes to two strokes .

Wow

I've used a welder 100 times , I've also jigged shit into a drill press and also used the tig arc to heat shit up , at 140hz it's a concentrated arc and a lot of heat then I'll mig lil dabs onto it . Just my opinion but I would tear it down

Measure top of deck to bottom of port in mm and same way to top of port . Only thing I can tell you on building cranks is standard true stands are no good , you have to block the center bearings and true each side center out. pressing them is the easy part . The hardest part is learning to use your tig to manipulate the web true , you can true something perfect then weld it and be out 3-7 thou , I've goot about 40 or so under my belt now and I'm getting quicker n quicker

The easiest way to do it would be Mail em or measure them with a digital caliper , I cant tell port style from pics or bore size. I also tried explaining they need a custom stock head rechamber/reworked for 70 mm bore , Pistons that big are like $250 for the rite ones . They need a copper head gasket from McDermott racing . Then you need to mock assemble the engine and figure out the deck height so mull engineering has an idea where to put the squish numbers along with piston crown setup, these engines are unicorn setups now and not many people can get them to stay together . It's definitely not something you just bolt together if you don't have all the pieces to the puzzle

Weav , these look like old school piano wire trinity big bore cylinders

If you give me the top of port measurements and stroke I can tell you timings

Repairs n mods section

I've see portiing like that a few times, it can be improved on with a lil feathering out and shaping . Rippen,as long as you shape the port correctly width hasn't ever been an issue , actually not wide enouph is a bigger issue on a single ex port engine because there's not enouph time/area to expel the charge before the transfers open.

Air leak

On my stock cyl 4 mill I run the 19's , on the cub I run 20's , 19's will work great for what your doing. Clutch tuning and ignition curve settings will make you fast

I can get you pretty close on a clutch tune if u get some American racers sd23 compound. Most imortantly did u have fun. Second don't get discouraged it took me over a yr to get out of 12s and even longer in the the low 11s , it's not as easy as people think. Back when I started running asphault was almost not existant aside from Tedder and STY . They pointed me in the rite directon , just be willing to listen. . I have ran bikes similar to yours starting out which I consider a trail bike the fastest I got it to go was11.8 @105 mph with a 1.5 60'

Only time I have a lil issue is with straight cut primaries

360,30,4th clip

Opening boost first is old school, I've done it but don't anym. You want an opinion don't do kinda shit, look at the skirt area where you have boost ports. With that much material any sort of failure and your cylinder will crack there. I've seen it many times on overprted stockers. I've found portiing tunnels too much greatly lower of ability to pull gear at and just after peak power . Making it rev quick and never go anywhere instead of freight training the gear

J that's why I rarely sell shit , not worth the hassle

Basket have play on gear?

I always use fast racing, rite now 35 pwk are back orderd. But that 500 should have no smaller than a 39 on it