sstaton1983 Posted March 15, 2014 Report Share Posted March 15, 2014 40mm carbs seem like way too much carb for a small motor... The smaller the carb the more velocity the intake charge has... Which will help primary compression a great deal.... With a big carb you decrease that velocity and get less effective crankcase filling... And you loose signal strength to mouth of the carb... Pressure is made by dead ends.. I agree . Most guys that ask "what mods will make my banshee faster"? Aren't running welded Cylinders . Does this guy need 38s with a 300 port job? And with t 5s. That's a waste of money unless he goes cub or spends a grand on his stock cylinders. Quote Link to comment Share on other sites More sharing options...
Toomey Man Posted March 19, 2014 Report Share Posted March 19, 2014 don't buy big bore kits they might not cost to much the rebuild kits are nuts guess get ur jugs bored out bro. Quote Link to comment Share on other sites More sharing options...
slimguy379 Posted March 19, 2014 Author Report Share Posted March 19, 2014 So I think I've narrowed down what I want, I recently purchased a cool head with 17cc domes for $100, v force 3 reeds for $80. This pay check I'm ordering 68mm pistons so I can have my cylinders bored. I checked with a bud that owns a local motorcycle shop he said he charges $55 a hole. So for $110 I'll have mine bored. Obviously I'm buying a jet kit. I already have my sprockets set. What else could I use besides a crank? I'm not sure if I mentioned it but my jugs are ported. Quote Link to comment Share on other sites More sharing options...
oldskool Posted March 19, 2014 Report Share Posted March 19, 2014 What type of cylinders do you have? Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 19, 2014 Report Share Posted March 19, 2014 Woah 68 pistons?? I thought you had stock cylinders. Now your talking about boring them to 68. Can't be done. And if your buddy at the shop said it can be, stay away from that place. You'll need new sleeves for that. At that point, go to a monoblock setup. Quote Link to comment Share on other sites More sharing options...
slimguy379 Posted March 19, 2014 Author Report Share Posted March 19, 2014 Stock, why woah? That's why I have this thread to get thoughts and opinions to which route to take... Quote Link to comment Share on other sites More sharing options...
Surfrjag Posted March 19, 2014 Report Share Posted March 19, 2014 get a hotrods 4 mil crank and have stock cylinders ported for the stroke and measured for new pistons. no point in boring unless you need to go to next size for correct piston wall clearance . then sell those domes and have some cut for a 4mil on whatever fuel you want to run. I can usually build one in the 1500 dollor range 1 Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 19, 2014 Report Share Posted March 19, 2014 ^^^ do that. It's simple and easy. Quote Link to comment Share on other sites More sharing options...
slimguy379 Posted March 19, 2014 Author Report Share Posted March 19, 2014 So stock cylinder is maxed at 66... why stroke over bore? I'll have to post pics of my crank to make sure I don't already have a mill crank Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 19, 2014 Report Share Posted March 19, 2014 Box up your cylinders, crank, and trans. Send to builder. Tell them what you want to do. Th inspect and make modifications from there Quote Link to comment Share on other sites More sharing options...
Surfrjag Posted March 19, 2014 Report Share Posted March 19, 2014 how much time is on your crank and how long do you think it will go? typically a stock crank will need to be trued and welded before it can reliably make a good amount of power without separating. If you want to put money into it without knowing how much time is on it, you may be gambling a little. Buying a new crank would be ideal to know you have a 0 hr crank. if your going to buy a crank you might as well go with the 4 mil because it gives a mechanical advantage with not only the longer rod but its pin is 2mm outside of the centerline of the crank. with this advantage and porting the cylinders to match the stroke it can be a long lasting 70-80 hp motor once tuned in. Boring a set of cylinders to the max means that you cant bore them any more. that means that if you do port them, then once you wear that size out, they are trashed or ready for resleeving. A big bore resleeve is typically 150 per cylinder and 90 or so for the sleeve each. If you have the money.. do both. or better yet get the 4mil crank and a 421 cub topend. but then your looking at a more of a drag motor. Quote Link to comment Share on other sites More sharing options...
slimguy379 Posted March 21, 2014 Author Report Share Posted March 21, 2014 So +4 mill crank, 66mm bore, +4 advance, 17cc domes, cool head, v force 3 reeds, reed spacers, just curious what else... Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 21, 2014 Report Share Posted March 21, 2014 Don't pick a piston size. Go to the next needed size. No reed spacers. Get it ported for the 4 mil. Get the domes for the 4 mil. Quote Link to comment Share on other sites More sharing options...
slimguy379 Posted March 21, 2014 Author Report Share Posted March 21, 2014 Piston/ jug bore is what I bought it with. Just had to check the piston top for stamped mm. Its already been ported Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 21, 2014 Report Share Posted March 21, 2014 Okay I didn't read through. Is it a 4 mil port? Contact some one for 4 mil domes. Preferably the person who ported it. They'll know what domes work on there port Quote Link to comment Share on other sites More sharing options...
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