lost power now wont start

[tschamp20]

hello everyone,while out today motor was running great.then it srarted losing power rpms dropped from 4800 max rpm down to 3800.then it would surge +300-400 rpms in short bursts.just barely made it back the 2 miles to ramp when it totally died.
compression is 112-115 on all cylinders.
4 new coils
carbs rebuilt
new-used stator i got from chinewalker
spark is jumping 1/2" on all cylinders,although seems a bit intermittent on #2
when i turn the motor over on muffs it acts like the battery is low or the motor is binding w/ plug wires connected.
with plug wires disconnected it turns over nice and smooth.
motor was just rebuilt by me about 5 hrs. ago,still doing break-in 24-1 ratio
basically the only thing original is the power pack which seems like a likely culprit but wanted to get some input from you guys to see if there is more i can do to diagnose.
this motor has sure been a test of my patience.but am kinda enjoying getting to know it inside and out.one more hurdle.thanks for any responses.

oh yeah just got a camcorder i could probably film what i mean about it binding when i try to start if needed

 

[tashasdaddy]

Re: lost power now wont start

pull the plugs, and turn it over by hand, using the flywheel, it should turn smoothly, see if you have any rough or hard spots, could be a bearing failing, heres some electrical test several pages find your motor. http://www.boatpartstore.com/page30.asp

 

[tschamp20]

Re: lost power now wont start

all seems smooth.
would a powerpack fire out of order if bad causing a scenario that im seeing here?
this seems to be very similar to some problems i had previously
with this motor.it only happens after 10 minutes or so at full throttle.
thanks again

 

[tschamp20]

Re: lost power now wont start

bump

 

[tschamp20]

Re: lost power now wont start

ok so after more testing using the factory manual and tashasdaddys link i think i may have stumbled onto something.
i did the test on the sensor coil(timer base) and heres what i found:
when i check ohms between the pairs of sensor leads i get 8.4 ohms which is good but when i check each wire to ground i get one wire that reads 24 ohms,which is not good.short right?
after confering w/ my neighbor who is an excellent car mechanic we believe this to be the culprit. does the timerbase act as a crank positioning sensor? if so would that explain why it seems to be binding when i try to start,as if the firing order is mistimed?due to the short.
i guess what im getting at is litterally the two things that i didnt replace during the rebuild were timerbase and powerpack,for obvious reasons i really cant afford to buy unnessesary parts.with the info ive given where would you go next.?

 

[ezeke]

Re: lost power now wont start

What was the torque setting on your flywheel?

 

[tschamp20]

Re: lost power now wont start

105 as per the manual

 

[tschamp20]

Re: lost power now wont start

what is your technique to hold flywheel from moving when torqueing? i used an oak wedge put cant say it was perfect.

 

[ezeke]

Re: lost power now wont start

Any sign of melting or discoloration under the flywheel?

 

[tschamp20]

Re: lost power now wont start

going to check,anything in particular?the block is painted white should be easy enough to see.

 

[tschamp20]

Re: lost power now wont start

clean as a whistle!
what do you make of the timerbase test results?ie : ohms reading to ground?

 

[tschamp20]

Re: lost power now wont start

i sure hope my soon to be born son likes breast milk,cause his formula money looks to be goin towards a timerbase and powerpack.peace out!