Author Topic: Motor wont run  (Read 3476 times)

Red

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Motor wont run
« on: April 23, 2013, 06:09:35 PM »
Need a little  help here! I'm trying to run my motor for first time and I have good spark and fuel but cant get it to pop off while turning motor with a drill

Mike Sal

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Re: Motor wont run
« Reply #1 on: April 23, 2013, 06:55:20 PM »
Pull the compression plate to see if there's too much gas.  Pretty common when first trying to get them running.  Do you have decent compression up and down on the stroke?
Mike Sal

Red

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Re: Motor wont run
« Reply #2 on: April 23, 2013, 07:13:00 PM »
got it to run for a few seconds on choke(got a better drill because the one I was using I think was turning too slow) and then nothing.Let it sit for a couple min. and then it will run on choke for a few seconds again. Could I have the float leveled wrong in the bowl?

pd

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Re: Motor wont run
« Reply #3 on: April 24, 2013, 07:04:31 AM »
Do you have an MT1 Tillotson carb ?

The book calls for 1 13/32" ± 1/64" . Others have found that 1 15/32" works better . I have mine set at 1.5" , but I'm currently running an MT9B carb and still having what seems to be a flooding problem .
Goes around , Comes around . :)

Red

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Re: Motor wont run
« Reply #4 on: April 24, 2013, 09:17:09 AM »
I have mt 57

pd

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Re: Motor wont run
« Reply #5 on: April 24, 2013, 10:01:51 AM »
The book also calls for the idle and main needles to be set at 1 turn out as a starting point .

How big is the throat of your MT57 ?

I tried an MT48A that has a throat size very close to the OEM MT1 size , but I couldn't get that to work well . The MT9B that I have mounted now , works much better . It has a much smaller throat size , by almost half .
Along with the smaller throat size , I have tried different amounts of fuel meter tube 'wall' holes . I'm currently running a total of 4 holes . That exactly half the amount used in the OEM MT1 carbs as well as the replacement Carter carbs .
Goes around , Comes around . :)

Red

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Re: Motor wont run
« Reply #6 on: April 24, 2013, 07:44:02 PM »
I had idle and main at 1 1/2 out. I went home and adjusted them 1 turn out  and got it to run on choke and full throttle for about 20 seconds and  then took it off choke and it killed. I put the drill back on it and never could get it to run that long again,only a couple seconds after it sits for a minute or 2.I havent taken carburator back off yet

pd

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Re: Motor wont run
« Reply #7 on: April 25, 2013, 07:17:53 AM »
Are you sure all the fuel passages are clear ? I use flammable brake cleaner through every possible hole and make sure I get a good stream out every corresponding hole(s) .

Always read the label before using chemical products .
Goes around , Comes around . :)

Ricks

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Re: Motor wont run
« Reply #8 on: April 25, 2013, 07:46:30 AM »
Just as an aside. I always used the one turn open on the needle valve adjusting screw, BUT, I was reading my 1950 manual and they say something different. Read the scan below.


I had never seen that before, and all other manuals I've seen have said 1 full turn.  Interesting!!
« Last Edit: April 25, 2013, 07:50:29 AM by RickS »
Rick

pd

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Re: Motor wont run
« Reply #9 on: April 25, 2013, 08:11:04 AM »
That is a pretty big difference . I wonder what was different to warrant the change of instructions .

I have my MT9B set at about 3/4 turn out and it seems to be running better , but it's still not there .

Rick , I have to agree with you that these used carbs may easily have been 'ham fisted' and the 'jets' may no longer be as manufactured . I know that that happens a fair amount on the old Honda CV carbs , some of which have been 'adjusted' into parts only carbs .
Goes around , Comes around . :)

Red

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Re: Motor wont run
« Reply #10 on: April 25, 2013, 12:42:21 PM »
Well I'm definitely going to try 1/4 out before I pull the carb off. I appreciate the help and input and will update this evening

Red

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Re: Motor wont run
« Reply #11 on: April 29, 2013, 06:29:37 PM »
Alright,so I pulled the carb and set the float then set the adjusting screws between 1/4 and 1/2 out and got it to run But with it wide open it would only run at best 1/2 speed and was spitting gas out the back of carb (but only while running) I tried adjusting on screw while running but nothing helped

simplexguy

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Re: Motor wont run
« Reply #12 on: April 29, 2013, 07:20:01 PM »
Is this a new rebuild? Double check your crankshaft seals, loss of vacuum could cause this problem