Recent content by RB55_2018

Great explanation!

I have messed with them before and really don't like them. I know they are supposed to create a continuously variable gear ratio that would allow you to have way more low-end power and a bit better top-end as well with the overdrive but in practice I could never get them to work properly. In...

UPDATE Today I tried to take the minibike out for a proper test run. Did nothing from yesterday except relocating the breather filter, installing the air filter on the carb, shortening the fuel line a bit, and adding some gas to the tank (from the same gas storage tank that I used to fill it up...

UPDATE I finally found the culprit. Out of all the most difficult problems to find in an engine, this is probably the hardest issue imaginable to find. I pulled the cylinder head and carefully examined everything. The bore looked to be in near-perfect condition, indicating that this likely...

Thanks a lot for the advice. I replaced the entire spark plug coil and boot with a new coil wire/boot and it didn't make any difference. Saw nice bright sparks as well and I know this coil works since I used it on another engine. I checked lash again and there was .0025" on both valves so I...

Hello All, I am fairly experienced at working with small engines, both 2 stroke and 4 stroke, but for the life of me I can't understand what's going on with 212 I just built for a minibike. Below is a list of the mods I did: Predator 212 Hemi, Stock Bore, Stock Stroke, Stock Valves, Stock...

As for the gearing, optimizing it for your setup is equally as important as upgrading your engine. If you want a top speed of 60 MPH and you gear your upgraded kart to reach only 5,000 RPM at that speed, your mods are doing absolutely nothing. The Predator is already optimized for low-end and...

Sorry but I literally just proved that there's no way that their "Stage 4" engine is making 20+ HP. Read what I said under the video instead of reading their numbers on a whiteboard. I'm not sponsored by a company trying to sell things like there are. Can you get a Predator 212 to 20 HP...

I use .003 for both intake and exhaust. You made a good decision upgrading the rod and flywheel for your Predator 420 but higher RPM alone will not increase horsepower with everything else being stock. The camshafts on the predators are made to provide low and mid-range power up to around 4,200...

I 100% agree with what you said about blueprinting. That's why I came here to ask questions and plan ahead before I started slapping on performance parts and messing with the engine. There are several websites and YouTubers who will sell/promote "Stage 4" kits or whatever "Stage" BS and claim...

I would love to order some of his amazing parts, but unfortunately I can only dream with those price tags... :( I’ll probably stick with just a head gasket swap as I confirmed that the piston compression height is .550 on a Hemi and .570 on Non-Hemi. Unfortunately, changing to a flat top piston...

I'll be sure to check valvetrain geometry after I do all these mods. I found a head gasket that is .009 which is amazingly thin. Should give me at least 9.5:1. Do you recommend I also use a flat top piston to further increase compression to a bit over 10:1, or is a head gasket change enough...

Thanks again for the advice. How much do you recommend advancing the ignition by? The offset keys range from 1 - 8 degrees of advance. I saw that the thinnest copper head gasket you can buy is .016". I calculated the dimensions of the stock Predator 212 using the listed 8.5:1 CR as a known...

Thanks for the advice. Seems like a great cam for my application. Would 1.3 ratio rockers help or hurt my setup? They're $10 each and seem like an easy upgrade for increased lift. I will use 22lb valve springs (no need for 26lb as I will never exceed 6,000 RPM). Also, if I order this camshaft, I...

Would doing those mods increase engine power at 5,000 rpm though? I know they support to 7,000+. I'm just afraid to spend a lot of money on nice parts and end up with little to no power gain at the RPM I want...