odaen

Did the plugs themselves ever back out on ya?

give cameron at redline a call and ask him. I'd almost bet he'd recommend sticking with your stockers or getting some 30mm oko's. who ported your cylinders? call them and ask.

You can do it, but I dunno how it would compare to just getting the 4mm casting performance wise. BigRed350X is the only one I know of that ran that kind of setup. Might call some builders and ask them too. I'm sure they could tell you with a lot more accuracy than us.

where do you ride? if it's some place that's got some large hills like pismo or sand mountain or glamis, I'd probably go with some larger carbs like 35pwk's, maybe some 33's. For oregon where the hills are shorter and such, I think a smaller carb will help you get out of the hole faster and build power quicker with better throttle response for treeshots and such. I'm sure you'll get a wide range of responses on carb size. But my 4mm dune port with CPI's ran like a mofo with stock carbs bored out to 27.5mm

You'll definitely need some custom domes cut to allow for the longer stroke, and run the thinnest base gasket, or none to keep your port timings down. I'd probably consider selling your stock stroke cub setup and using the proceeds for a 4mm casting though. I think it would probably run much better. Good luck. :thumbsup:

The single carb setup seems to be a love it or hate it kinda deal. More times than not though, I've heard of people taking them off to go back to dual carbs. Maybe they just don't have the experience with them to set them up properly. The jetting is quite a bit different than dual carbs and far less people run them, so, I dunno. Personally, I like the idea. One carb to setup and jet, no sync'ing necessary, etc. However, if your trail bike is kicking his drag bike's ass, I'd say it has very little to do with his 35mm dual carbs vs your single carb, and much more to do with gearing/paddle/rider ability than anything else.

I'd say stick with your stockers(can get them bored to 27.5mm), or go with some 28pwk's or the 30 oko's (clone of the 28pwk). You will lose more throttle response and bottom end torque the bigger the carb you go.

Yeah, you misunderstood what I was saying. I was comparing same stroke/rod length motors, not a 4mm vs a stock stroke. And, yes, I agree, that you can't just add 2 mm to your port heights to make up for the 4mm crank and expect to have the same durations as you had with a stock motor. If that's what you were getting at with the term linear. :beer:

I'm not sure what you're trying to say. What I'm saying, is that given a motor with the same stroke and rod length, you can move the deck height up or down, and the port openings will have to move the same distance to yield the same durations.

Yeah, it's different. A non plate motor basically has a negative deck height around 2mm to make up for the longer stroke (ie pistons coming out the top of the cylinders 2mm). So, the ports would need to be 2mm higher to keep the same duration as a motor that is setup for around a zero deck heigh (spacer plate motor). The overall cylinder height doesn't matter. What matters is the deck height, stroke, rod length, and distance the port opens with regard to the deck.

I think there's something wrong with your exhaust measurement for sure, since stock is about 30mm. But it would seem that if your transfer measurement is correct, it's setup to run the spacer plate, because it's sitting at the stock height, which will give you a transfer duration of around 131 or 132'ish. Without your spacer plate, the durations would be in the low 120's, which doesn't seem to jive with the typical drag porting numbers I've seen. But, you may want to measure both again to be sure since the exhaust is for sure fubar.

The nology coils seem to be popular on here. That is in no way an endorsement by me, I have had good results with stockers :biggrin:

Get a NOSS head. He's a sponsor on hq too and I think gives you a price break if you mention it. Also, be sure whatever route you go to get the pancake bearing for your clutch.

I think for the money, you can't compete with a NOSS head. Stock ignition is fine, but do get the adjustable timing plate, and I'd recommend getting the NGK boots for your plug wires. As for the clutch, if I were gonna put a 4mm cub together for duning again, I'd probably opt to just use a beefier clutch than run a lockup again. You lose an inch or so on your right peg, and your rear brake pedal needs to be adjusted down and out of the way. I dunno, I like riding tight in and not having to articulate my foot 90 degrees to get my rear brake to start grabbing. But that's just me. They do serve a good purpose and look tight as shit if you are into the bling factor. 39PWK's seem to be the carb of choice with the cub motors, but I'm sure your 38 mikuni's would certainly fit the bill. Good luck, man. I remember being in your position looking forward to my next mod on my bike.

Fill the radiator up.

I think it depends on your budget and end goal. The 4mm cub would work great with your setup now. With race gas, you are probably looking in the 100'ish HP range. The 7mm cub would require you to buy a new crank, which are about double the price of a 4mm crank, you'd need to trench your cases and probably be around 110'ish HP on race gas. For identical cost pretty much, you could go 10mm and probably be around 115'ish for HP. It's hard, well it was hard for me anyway, to distinguish what was enough horsepower for my needs, until I went too far. I went from a 76HP 4mm dune port that was probably optimal for my riding style, and setup to a 4mm cub that dyno'd a little over 100HP. It put a huge grin on my face every time I rode it, but it was very very impractical for anything other than riding in a straight line on a flat surface. I was constantly running back to camp to fill my bike up, while my buddies on their 450's rode for hours and hours on a single tank. Anyway, good luck, and whatever you decide, keep us posted. It's nice to see bikes progress on here.

Advancing the timing will help with your bottom and mid-range power. I'd also recommend the T5's and VForce reeds. Mill your head to raise the compression some and you'll be in good shape powerwise.

Might want to get a can of carb cleaner and with your bike running, squirt it all around your intake area to make sure you don't have an air leak when you put your new reeds in.

I'm sure A&S, RDZ, or GRR could help you out with that. They're all from Michigan. Jankab on here also is from Michigan too, send him a PM.

with the info you gave, it's hard to tell what's going on a bad head gasket or o-ring if you have a coolhead can pressurize the cooling system and force fluid out the overflow. start your bike and pull the radiator cap off. sometimes you can see air bubbles coming up a bad water pump impellar would definitely cause some overheating in 1/4 mile too

yeah, meaure from the top of the cylinder to the top of the exhaust port, and your transfers.

stock hp is around 36 or 37 with pipes, milled head, air filter, and some timing advance you can hit around 50ish add a mild port job and you'll hit 60 pretty easily

60 for the CDI 25 for the Coil prices are shipped email [email protected] former member eehsnab on here

They recommend a preloaded setup for duning....was in the same boat as you Wes. But they resprung the front and rear and revalved them all for like $400 + shipping. I thought that was a good deal and they were definitely much nicer than the stock setup, especially the rear since I had an extended swingarm and weigh about 210.

I've read multiple times that it's better to buy a matched set of cases rather than just replacing one of the 2. :shrug: