Pull Start

[Craig Hollingshead]

I have a Zenoah 300PUM with the pull start. I want to remove the pull start and go with a pulley and starter. I removed the black cover, however, I am unsure how to get the rest off...any help would be great!!

Kind regards...Craig

 

[Mike Hughes]

You need to get the pall off. There are 2 types. Both of which you can grab easy with a pair of channel locks. The best bet is to use a L allen to hold the fly wheel from turning. Put the short end in one of the threaded holes in the flywheel. Use an allen that jsut barely fits in order to give you the largest long length. Then untighten the pall. Counter clock wise. The allen will jam up against center point and you can stop the flywheel from spinning. Reverse process for installing pulley. Dont use a piston stop. You can twist the crank. Easy to do with the zenoah cranks since the pin fit is not that great.
Mike

 

[Craig Hollingshead]

Well...that was easy!! Grassy ass amigo!!!!!

 

[Daniel's Racing]

You need to get the pall off. There are 2 types. Both of which you can grab easy with a pair of channel locks. The best bet is to use a L allen to hold the fly wheel from turning. Put the short end in one of the threaded holes in the flywheel. Use an allen that jsut barely fits in order to give you the largest long length. Then untighten the pall. Counter clock wise. The allen will jam up against center point and you can stop the flywheel from spinning. Reverse process for installing pulley. Dont use a piston stop. You can twist the crank. Easy to do with the zenoah cranks since the pin fit is not that great.
Mike

Only problem is that will not work for a EZ Start pawl nut an especially a cut down pawl nut that we all run so you don't need the spacer.

The threaded holes in flywheel are completely blocked by the pawl nut.

You have to remove the jug and shim the crank between it and the case on half of crank towards the end your working on with nylon or leather piece that won't damage aluminum. Full circle crank you have to use side of the rod.

If you take the flywheel off then you hold flywheel by bolting a tool to face of flywheel and using steel washer and nut to fully seat the flywheel first.

NEVER hold the engine from the collet side working on the flywheel. You have to hold the end you are working on.

 

[Don Ferrette]

If you are thinking of putting the pulley on the front I've heard a couple different well known Zen engine builders say it's not a good idea to put a starter pulley in place of the pull start pawl as you can bend the crank (you're placing the upward pull directly on the unsupported area of the crank vs. pull start being anchored to the the case/front mount). It's supposed to be better at the collet end as the upwards pull placed on the crank during starting has a bearing right there to support/stabilize it unlike the front. I personally like the super collet from Joe Petro over at Zippkits-
https://zippkits.com/index.php?main...id=225&zenid=50e79bf9bdda44bb4b7b923bb4e7ef80

 

[Daniel's Racing]

It is not a issue to start from flywheel end.

You have it backwards. Back by the collet end is where problems can/could come from .

It isn't about the unsupported ends and way more about trying the snatch the flywheel up to speed from the wrong end.

The flywheel is the end you want it on to get that chunk of metal up to speed directly attached to it not from the other end of the crank.

You don't have to pull hard on the belt at all when pulleys are right and using a belt that fits them with a starter with enough oomph to turn it over. I mean you really don't hardly have to pull at all just tension up the belt a little bit.

Lot harder to tweak a crank pulling up on a end than it is to put twisting force across the crankpin joining the halves while you trying to twist the crank getting heavy flywheel moving from the collet end. You might as well be wrenching on one end while holding it from the other. Same thing and we know better than do that.

Literally thousands of engines being fired every weekend with electric start from flywheel end year after year with zero issues.

You would never pull hard enough on the belt 1 1/2" from the bearing to make it a problem. You should not have to pull the belt very tight to start a engine.

Neither end really matters unless your crank has very weak press fit I don't think collet end is a issue either.

Just imagine if you will for a second the forces at work. Imagine the forces across the crank with prop at one end and flywheel at the other like when say the boat leaves the water and re-enters.

If your using a weak starter you have to slip the belt with to start it that may be a problem as you do have to pull pretty hard to get lockup from a full rpm starter motor. The starter should have enough oomph to start from a standstill with the belt already snug.


The only people I have ever heard say not to use flywheel end for pulley was Quickdraw and that is ONLY because they feel with the extra extended length pulley you need to clear the longer engine it may be a problem with extra bit of leverage. That and nobody makes a pulley to fit anyhow so mute subject for almost everyone anyway. Well I made a few for a guy and QD said not to use them. He still used them without issues.

 

[Wasted wages]

Wouldn't mig welding the crankpin take care of any pin/counterweight twisting issues?

I mean it's not like these are high dollar cranks we are talking about...
Once the rod or crankpin bearings are roached, just throw in another crank..

 

[Rich Jones]

It is not a issue to start from flywheel end.

You have it backwards. Back by the collet end is where problems can/could come from .

It isn't about the unsupported ends and way more about trying the snatch the flywheel up to speed from the wrong end.

The flywheel is the end you want it on to get that chunk of metal up to speed directly attached to it not from the other end of the crank.

You don't have to pull hard on the belt at all when pulleys are right and using a belt that fits them with a starter with enough oomph to turn it over. I mean you really don't hardly have to pull at all just tension up the belt a little bit.

Lot harder to tweak a crank pulling up on a end than it is to put twisting force across the crankpin joining the halves while you trying to twist the crank getting heavy flywheel moving from the collet end. You might as well be wrenching on one end while holding it from the other. Same thing and we know better than do that.

Literally thousands of engines being fired every weekend with electric start from flywheel end year after year with zero issues.

You would never pull hard enough on the belt 1 1/2" from the bearing to make it a problem. You should not have to pull the belt very tight to start a engine.

Neither end really matters unless your crank has very weak press fit I don't think collet end is a issue either.

Just imagine if you will for a second the forces at work. Imagine the forces across the crank with prop at one end and flywheel at the other like when say the boat leaves the water and re-enters.

If your using a weak starter you have to slip the belt with to start it that may be a problem as you do have to pull pretty hard to get lockup from a full rpm starter motor. The starter should have enough oomph to start from a standstill with the belt already snug.


The only people I have ever heard say not to use flywheel end for pulley was Quickdraw and that is ONLY because they feel with the extra extended length pulley you need to clear the longer engine it may be a problem with extra bit of leverage. That and nobody makes a pulley to fit anyhow so mute subject for almost everyone anyway. Well I made a few for a guy and QD said not to use them. He still used them without issues.

I’ve used Daniel’s pulleys and starter belts on the flywheel end for the last 2 years with no issues at all. The only issues I’ve had since getting back into the hobby and getting into gas have been carb related mostly.

 

[Craig Hollingshead]

Well then...thanks for all of the input. There seems to be two different camps on this. It makes sense to me to start from the flywheel end...but what do I know...lol. I am just getting into this hobby and I need to rely on the experience of those ahead of me.

Kind regards...Craig

 

[Daniel's Racing]

There are way too many people starting from both ends for it to actually be any problem at all.

Now you have to use common sense of course too. Bump it good with the starter with water still in the engine that would be a problem. Easy mistake to make I suppose. Don't do that !!! Lol.

The way these ideas get started that belt starting is a issue is usually something like a guy sends a engine in to his builder and builder says you have bent crank. Builder not being a avid electric start guy to begin with asks if guy uses electric starter which he does. So it is now the starter that did it not the full throttle wipeout that ingested water last time it ran good.

Many scenarios on how people may form a opinion about electric starter use but used properly there is absolutely no chance of you tweaking a crank during electric starting of a engine. If you ever did you either had a crank issue already or you pulled water up from the crankcase and locked it up.

You can't be lazy you MUST get all the water out after a flip. Something the electric starter does well is clearing the engine. First you have to pull the plug, drop piston to BDC and dump what water you can out of engine and pipe. Then before you put the plug back in bump the engine with the starter once or twice for like 5 seconds.

People coming from electric starting nitros already know this but we could have some in gas that maybe didn't get that expirience first.

 

[Don Ferrette]

So the info about front mounting of pull start pulleys being bad that I had is from a number of years ago (one builder I used to use lit into me when he saw the pulley conversion I made from a CMB90 Evo flywheel and the starter pawl). So I reached out to a couple builders I now use and asked about it. They said it's really not an issue these days with were the Zens have advanced to and starting with pulley from either side is fine. Both also said what has already come up and should be a no brainer, don't hit that electric starter on a dunked motor until you're sure all the water is out. So to Daniel and others I respectfully retract what I posted previously.