JLO L297 with a Tillotson HR67A

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I remember reading the old engines said to mix 30w motor oil with the gas 
Bet that's why you had Extra Plug holders with your tool kit ! 

[lislandjoe]

Yeah TRUFUEL.   NEVER again will I use that stuff.  According to my research the JLO calls for 20:1.  The motor runs like a champ now.  I just gotta stop breaking chains.

[wedge]

TRUFUEL ! You mean that premix you get in a can ?
Man Stay AWAY  from that crap !!!!!!
First off that engine runs 40:1 Not 50:1. Second that stuff is CRAP !!!!
I get two to four engines in the shop that don't start with That in the tank !!

[lislandjoe]

Got it running.  Took the plug out. Poured two containers of 2-cycle oil and let it sit for 2 days. Every time I walked by it I rotated the crank by hand a few turns. I drained the oil out of the bottom of the crankcase. I used regular 87 pump gas and two stroke engine oil instead of trufuel. Fired right up and runs beautifully. I guess they didn't have this trufuel premixed stuff 50 years ago.

[joemeg]

 I'm far from an engine expert but have gleaned some things by hanging around the pits at Pine Lake. My first guess after reading your post would be the Crank Seals also.

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If the engine has been sitting for some time the Crank seal's can Dry out .
Even if you have Great compression it won't run as it is Sucking air past the crank and not through the carb.
You will need to pull a leak down test on the crank case to see if the seal are bad.

[lislandjoe]

Still can't get this JLO L297 running.  120 psi compression.  Tillotson HR67A carb has been rebuilt.  Complete disassemble including drilling welch plugs.  Metal parts soaked in Chem Dip.  Reassemble using new tuning needles and o-rings, inlet sleeve, needle, lever, and spring. All gaskets and diaphragms replaced as well.  Set high and low needles to 1 1/2 back from bottoming out.  Pulled spark plug and cranked with plug plugged into plug wire.  Definitely has GREAT spark.  Spark plug cleaned.  Got it to run for about a minute.  When choke is closed it spits fuel out the carb intake.  Start to open the choke and it no longer spits fuel.  Tried 1/4 and 1/2 turns both directions on the low and high needles.  Its just wont start.  What else can I try.  I really want to try and get this running before the expense of a new motor, pulleys, mods and whatever else.  Thanks.

[wedge]

It was fitted with the same style engine as you have out of the box. Same rotation as with most engines But you will more than likely need a Clutch. I have a Small one like used on go karts that will work if you want to save money ?

[lislandjoe]

What motor did your amphicat have before you put the predator in? I know I need to consider RPM, rotation, shaft size, and clutch pulley for the belt. Does anyone know the RPM of the JLO L297? I know looking at the motor, the clutch pulley side, the rotation is counterclockwise. I know the shaft has a half moon quarter inch keyway and the end of the shaft is threaded as opposed to having a hole with threads that a retention Bolt would thread into. Is there anything else I need to consider? I know mounting will be really easy the way this is modified already. I know I need to make sure that the distance from the mounting bolts on the bottom of the motor to the center line of the pulley is the same as what I have so I don't have to offset the motor to line up with the Apex gearbox.

Ultimately I would like to find an aftermarket replacement carburetor for the tillotson HR67A carburetor. By just swapping out a carburetor the machine should be up and running. I have great spark and 120 PSI compression. The mechanical end of everything is solid best I can tell despite the heavy modification and addition of an apex gearbox.

[wedge]

That is you Best move !!
I put a Predator 420 in my Amphicat. LOVE IT !!
Just need to change the throttle set up like I did.

[lislandjoe]

Is there an after-market carburetor that would directly bolt to the motor?  I am having a fit with this carb.  Going to be a trail machine not a racer.  Speed is ok...but does not need to scream down the trail.  I am seriously considering just putting a new Predator 4 cycle on there and being done with it. This is not going to be a restoration or anything I want to sink a lot of money into. This is just another toy I picked up on an Impulse buy that I thought it would be fun to play with.