RadarRacing

No limit , Andy has a good crank he assembles in house. TDR has a few choices but will admit the cheaper ones shoukdnt be used in high hp applications. Crankworks has billets and I am sure Redline has them as well. I dont know if redline has a forged one that would be less $ than billet.

Looks like detonation damage to me. It also looks like the rings are melted into the piston and then maybe part of the ring is either gone which scarred the piston up or metal of some kind has hit the piston. Either ring piece or crank bearing. There is detonation damage there too from high temps but detonation marks are mostly on the squishband area of dome and piston. You have that plus what looks like ring hitting piston. Detonation causes temps to skyrocket very quickly which probably ended up doing the frint side of the piston where the ring is melted into it.

I see tons of bikes with just stupid rich needle settings. They are dogs in the low-mid throttle position. They are much more fun when the needles and jetting is spot on. Your bike may be rich on the main too. If the main is rich it will be sluggish and clean up when going thru the gears but then may burble up top from being rich. To answer your question about needle position effecting any other circuits. Yes they do but only a small amount. If for example you had a bike jetted right on the edge perfectly on the mainjet then leaning out the needle a clip or two would be bad. Otherwise it is really 1/4-3/4 like Special said.

^^^ Thats awesome. Ebay has the best race parts of course. Lmao.

There are tons of em. K&T runs 38s or bored 38s on most of their cubs. 4,7,10 mils.

I misread that and thought the 521 was the 421 and 85hp. The super servals I have seen werent impressive at all. I tuned a 472 super serval last year done by a site sponsor that supposedly had em lined out that was a combo that wouldnt tune until the 4th cutting of domes and pipes and ended up being 85 hp on 110 octane. That puts them into the "I dont want one" category. I cut the domes twice and luckily we only went thru one piston and one dome. There are a couple servals of guys on here that are now drag ported like cubs and on alky cuz they wouldnt run worth a crap as servals. That is with snipers , shearers and cpis. I would definately stick with a proven builder with a proven combo. Otherwise skip the super serval IMO.

I wouldnt even do the super serval unless you just wanted to. The regular serval cubs are just about the same if not more power than the super. A 10 mil serval is quite a bit cheaper to build and will be easier to tune in my opinion. I know of several servals that had tuning probs when they first came out. Now they have them lined out better.

Listen to Redline. It needs leaner needles. It really needs leaner dumptubes as they are drilled too big but with leaner needles it can be fixed hopefully. It probably shoulda had .120/122 dumps with the EGN or EGL needles. Somebody screwed up there. I would see if Cam at Redline has a good guess as to needle for you and get em from him.

Hookin somebody up with his own parts that were stolen from him. NOW..That's customer service. Lmao.

You will be fine ghott. It of course isnt recommended but it wont hurt em unless you cut em on glass or something sharp. If they are crazy thin you may not want to. It seems like none of the buffed tires are buffed half as thin as they used to be.

Super serval. See of cam can get you a pumpgas 100 hp 10 mil. What cranks does he sell for the 10 mils. Hope someday someone comes out with a good forged 10 mil again with good rods.

Vitos 4 mil and stock stroke cranks have always been good cranks.

Never had any problems with any twist throttle on any bike of any kind. I think its easier than a thumb to get partial throttle but I also think its sacreligious to have a twist throttle on a quad. Like a guy that just couldnt learn to use a thumb throttle. Try a skidoo throttle sometime , or a seadoo toggle or a honda pwc watercraft trigger throttle Those are all different.

If you dont have a spot reserved they are more than likely all sold out unless you find a place closer to town.

Braided lines make a huge difference. Stock banshee fronts are horrible.

No on the starting fluid. It doesnt dissolve varnish, dirt very well. It also is very volatile and catches fire way too easily to be a safe cleaner.

Sale pending.

No need to measure or check carb. It is a 40mm lectron. Good carbs , they do however adjust differently and or "jet" differently than a mikuni or keihin. 40mm would be plenty of carb for it.

^^ I am with these guys. Stick with the 4 mil or start over. You wil be out maybe what $400-600 by selling your 421 used and getting a new 10 mil cyl. Honestly if you think it runs well now it will only run worse. If it runs like ass then maybe someone can fix it into a half assed 10 mil for ya. Not hatin , just answering your question.

Billet intakes/intake for 34-38mm carbs. Boots are genuine mikuni and perfect shape , seal fine. $85 shipped , Paypal ok. Thank you. Radar/Todd Links to pics. http://sandslingers.com/uploads/monthly_03_2014/post-7-0-99459500-1396230968.jpg http://sandslingers.com/uploads/monthly_03_2014/post-7-0-62923000-1396231015.jpg

Listen to those guys , I have usually seen 35mm pwks in the 145-158 range and 39s in the upper 160s,low 170s but we use CEL needles which are leaner than some and use different builders domes , higher ign timing etc. Thats all a factor in jetting.

165 is usually at the bottom end of jet size for 39mm pwks on the bikes I have jetted. I definately wouldnt start there. I would start at around the 175 range and go down if needed. If you have to give it gas to start it then it would either be one of 3 things 1. Needs to have the idle screws set correctly, carb syncing is very helpful. 2. Is lean on the pilot. 3. Is rich on the pilot, airscrew, needle Usually they will start easy if they are overly rich down low. You can probably tell if it starts easier if the chokes are needed all the time that it may be a bit lean on the pilot.

They are a badass tire , they just dont have an equivalent tire to equal the larger rollout 12-14 paddles for the +10-+12 swingaem guys. Skat trak has just kept going up in price and their quality is going down. Their pqddles are all crooked and arent buffed very thin anymore. Even on $900 sets.

If it starts decent and runs ok thwen it probably doesnt need a bore and new pistons. You wont gain anything going up half a dozen ccs. Put new plugs in , 320 mains and run it hard under a load all the way up ito 5th , kill the motor and coast to a stop and tell us what the plugs look like and if it ran better. If it ran worse that tells ya something.

I am from a northern province of oklahoma called kansas but luckily I am a foster child of crazykane. Lol. What kinda riding do you do? Trail , dune, race drag?