Billet Flywheel / Connecting Rod Necessary?

[yellow azusa]

I did the governor removal, Mikuni Carb and a header on my non-hemi predator 212. I just finished putting the 18 pound springs in. I've since read that you need the billet connecting rod and flywheel if you are doing 18 pound springs? Can I run the 18 pound springs without the billet flywheel/ connecting rod? I'm not looking to run this engine and high rpms for extended periods, just brief bursts of WOT. Hoping I don't need to tear the engine apart again. Also, if anyone has any suggestions on how to remove/ reinstall the springs with split valve keepers (no lash caps), that would be appreciated. Nearly destroyed my thumbs trying to get those little bastards in there without any tools. They flew across the garage twice and took me over an hour to find them!

 

[madtom421]

18lb springs will allow the motor to spin higher rpms before valve float, rpms the stock rod and flywheel were not designed to handle. It's taboo on here to talk about governor removal without adding a billet rod and flywheel. Maybe take a quick glance at the forum rules.

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[minibikin']

If you don’t have a spring compressor, use a wrench to press the retainer down. I use a small screwdriver with a dab of grease and put the lock in place with it.


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[EVOL Tweety Bird]

Somewhere in my collection of tools I hardly use is a valve spring compressor for removing/installing valve springs with the head installed.
Simple thing actually, piece of flat steel bent 90 degrees, with a short and long leg. The short leg had a slot in it to slip around the rocker stud.
You would pull the rocker, spin the nut back on and slip the tool under it. There was a hole back where the tool made it's bend for the valve stem to go through. Pull back on the long end, it would compress the spring and the stem would pop up through the hole. Easy to remove or install the keepers or springs with it.

Wouldn't think it would be that hard to make something like this for these small engines.

 

[FOMOGO]

Stock flywheel......

 

[EVOL Tweety Bird]

Man that would have been an unpleasant experience. $200.00 for a billet flywheel and rod sure beats the cost of new pants and underwear, and a trip to the emergency room.

 

[Daniel Coop]

A flywheel is always a good IDEA from a safety standpoint, and a necessity when turning anything over 6k RPM...You can wait on the rod until you decide to do a cam, IMHO... I suggest doing a little more research. There's a AKRA (kart) racing class called Box Stock where they race ungoverned, but otherwise stock clones with re-jetted carbs, air filters and 15" max single stage pipes with a silencer.

 

[MJL]

Do you at least have a tach? Personally, I'd have a hard time backing off when she was roaring along!

Reminds me of when I was younger and I had a 5 speed Civic with nothing but an intake. Man, that thing loved winding up to the red line! So I lived there! All was well until I blew a seal or ring somewhere in the motor. After that it drank a quart with every fill up and looked like a crop duster going down the road! I didn't have the money to fix it so I drove it like that for another 70k. A mechanic told me to run 20w50 so I did, and it helped with the smoke, but the cold dry starts are what eventually killed the motor at 221k.

 

[yellow azusa]

Thanks all! I'll be looking at flywheel/ rod as the next step this Spring. Will need to hang tight for a while on spending more $. This minibike project has gotten pretty spendy!

 

[madtom421]

Thanks all! I'll be looking at flywheel/ rod as the next step this Spring. Will need to hang tight for a while on spending more $. This minibike project has gotten pretty spendy!

I hear That! My $60 baja warrior has turned into $800! I told my wife it would only cost a couple hundred to fix up lol....that was before I decided to hop up the motor

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[yellow azusa]

Got it sorted out. She is purring like a kitten!

 

[manchester1]

I did the governor removal, Mikuni Carb and a header on my non-hemi predator 212. I just finished putting the 18 pound springs in. I've since read that you need the billet connecting rod and flywheel if you are doing 18 pound springs? Can I run the 18 pound springs without the billet flywheel/ connecting rod? I'm not looking to run this engine and high rpms for extended periods, just brief bursts of WOT. Hoping I don't need to tear the engine apart again. Also, if anyone has any suggestions on how to remove/ reinstall the springs with split valve keepers (no lash caps), that would be appreciated. Nearly destroyed my thumbs trying to get those little bastards in there without any tools. They flew across the garage twice and took me over an hour to find them!

OldMiniBikes just did a live video talking about that. You can probably find the video on you tube.

 

[DeadPixel]

I would not put the springs in tell you at least replace the flywheel. I would have bought the flywheel before the carb. Don't want to see ya blow a motor. Nice bike. Be careful tell you replace flywheel and rod.

 

[yellow azusa]

I would not put the springs in tell you at least replace the flywheel. I would have bought the flywheel before the carb. Don't want to see ya blow a motor. Nice bike. Be careful tell you replace flywheel and rod.

OK. Sounds like billet rod and flywheel are next on the list... Any reason not to do the mod 2 cam while we are in there?

 

[DeadPixel]

Sounds like a good plan.

 

[yellow azusa]

Well, I decided to take the mini bike around the block this evening and it started on the first pull, ran fine for a few minutes then it started to hesitate and died after a few seconds of running rough. I wasn't running WOT, just cruising. I walked the bike home and pulled the brand new plug Autolite AR3910X(see attached). Looks like it is running way rich right? I put the original plug in which was basically new as well and same problem. the engine just wouldn't fire. I checked the kill swtich, gas is flowing to the brand new mikuni carb and both plugs showed spark when I pulled the chord. I am going to look for smaller jets for the mikuni but any other suggestions would be much appreciated.

 

[DeadPixel]

Maybe your float got stuck.

 

[yellow azusa]

Figured it out! The bolts holding the carb onto the engine had backed out. Put some locktight on them. It is definitely still running rich (at 5k ft altitude here) so I ordered a smaller jets and will put that on when the new flywheel arrives.

 

[yellow azusa]

OK, installed the proper size jet in the mikuni 22 (size 115). Also installed the billet flywheel. Bike runs much stronger and revs higher but one thing my son noticed is that sometimes the pull chord will violently "snap back" when he tries to start it. It doesn't do this every time but it has happened a few times and it is kinda painful when you are pulling hard and the handle gets yanked from your hand. Any ideas on what could be causing the snapback to happen? Also seems to run better with the autolite performance plug vs the stock plug? Does any of this have to to with the timing advance that the flywheel has?

 

[EVOL Tweety Bird]

Make sure he's starting it correctly. With the compression release all it takes is a little tug to start. If he's not on the compression release it will do just that. From the manual, Pull the Starter Handle gently until resistance is felt. Allow Cable to retract fully
and then pull it quickly. Repeat until the engine starts.

Also as a side note, if the valve lash is not correct you can override the compression release and it's a bugger to start.

As for the plug, that's the first mod that should be done. The stock plug is doo doo.