# Poulan Pro 430VS- no start



## milliesdad (Nov 11, 2013)

New piece of equip-new thread

This devil had spark, compression-going to go into carb when I get a chance. Would not start or anything with the SeaFoam in spark plug hole trick. Usually can get something with that, but not this time.


----------



## jow (Aug 16, 2012)

How was it stored and the last time used with fresh treated fuel?

Was it stored with fresh Stabil or Etc fuel additives in fuel on run Bone Dry?
How long has it been stored?


----------



## jow (Aug 16, 2012)

How was it stored and the last time used with fresh treated fuel?

Was it stored with fresh Stabil or Etc fuel additives in fuel on run Bone Dry?
How long has it been stored?


----------



## tractornut (Sep 17, 2010)

Make sure that the fuel lines are in good shape too.


----------



## davbell22602 (Jan 10, 2013)

Did you use a compression gauge? What did the gauge read on the compression tester? What did the piston look like when removing the muffler to see it?


----------



## jow (Aug 16, 2012)

More history and inspections helps as “all” asked above.



Is new, new to you as the 1st time owner/user. If so, how long have you own/used?
As you said, most monsters are manageable once you learn their nature of operating.
Attached is inspecting a 1980s Poulan S25 cylinder and rings for scoring/wear (no lines/smooth).
.


----------



## milliesdad (Nov 11, 2013)

Don't know how it was stored, because it was a "barn find" at my local small engine shop when I needed some supplies.

I opened up the gap on the plug to 3/8th, and the spark jumped it. Rule out spark.

It does fail the "lift up on the recoil handle and see if it stops comming out at the compression stroke" method. Yes, it's very unprofessional but I don't have a compression tester.

It did not fire with the "Seafoam in the spark plug hole", and it did not fire with "pre-mix in the plug hole"method. Tomorrow it might get the "starting ether" methiod.

Leads me to beleive that it's a compression problem, but first the carb will come apart for a cleaning.

But, the piston kit is $35.00, so it's not a budget breaker. If I get him running, I'll be looking for a vacuum attachment kit for him.


----------



## davbell22602 (Jan 10, 2013)

Starting fluid ruins small engines.


----------



## jow (Aug 16, 2012)

Can you hold the compression in the cylinder with your finger while cranking (that is an old school test and you s/n be able to)? BUT! New low compression start might out/weigh that.
Is the 35.00 including a piston with rings and a cyl. I rebuilt once due to only needing the piston and rings (50.00) vs another 50.00 for the cyl.
Good Luck!


----------



## milliesdad (Nov 11, 2013)

$29.95 for piston, rod and ring. $10.95 for gaskets. 

Took it apart and the cyl looks brand new, still has hone marks-I think that Poulan splurged and had the cyl chromed. Piston and ring is toast-scuffed badly.

For $41.00 I'll put I'll got the parts ordered and will get him up and running-I hope.


----------



## jow (Aug 16, 2012)

My S25s had chrome cyls but a wrist pin keeper failed and ruined one. One was a keeper that just needed the piston/ring set.

What do you feel caused the failure? Such as; the keeper failure was not on me IMO (after 10 yrs I had no no complaints). The 2nd S25 I feel was on me due to working in 100+ degree weather or getting my oil mix off after 10 yrs. I used left over 50:1 from my boat and possibly d/n add the extra oil to make it 16:1 (the tint possibly threw me vs excessive oil).

Good Luck!


----------



## milliesdad (Nov 11, 2013)

Hard to say what caused the failure, but I would beleive it was not enough oil mix. 

The bad spots on the piston were at the inlet and outlet only-so I'm guessing heat caused by not enough lubrication. 

Parts should be here tomorrow, and I hopefully will have it running by the weekend-DI'm newly retired and this part time job I have is starting to be too much like a real job)


----------



## jow (Aug 16, 2012)

Consider, research or question more experience Techs if a lean Carb mixture could have contributed to this damage. Approximately what is the carb setting “out” from a light seating?


----------



## milliesdad (Nov 11, 2013)

Parts came today, got it together and running-

Runs for a short time and dies-30 sec or so, longer if I feather the throttle 

The carb idle speed screw is all the way out-not touching the throttle lever. Have not tried any carb adjustments-really don't know where to start.

Hope someone more experienced with these carbs chimes in.


----------



## milliesdad (Nov 11, 2013)

Got the manal downloaded.

Poulan wants 40:1 mix synthetic 2 cycle oil. No dino oil. (maybe that's what helped melt piston?) Carb is not adjustable except for idle speed-

Will get a fresh mix of 2 cycle fuel-I'll use Poulan oil if I can find it. And maybe make the mixture heavy on the oil. A little more oil never hurt, and the worst that can happen is fouling a plug.


----------



## jow (Aug 16, 2012)

Please attach a good close Picture of the bad piston. Hopefully someone has seen this and know the definite problem before it's damaged again. Approx how many years or hrs did you use the saw before the damage (w/o me looking back)?


----------



## milliesdad (Nov 11, 2013)

Got fresh gas-oil mix with what Poulan recommends. 

Runs a lot better, but I still can't get it to idle. The idle speed screw will not screw in to increase the speed.

Don't know how to post pics on forums, not that computer literate.


----------



## jow (Aug 16, 2012)

Reasons for a *Poulan Pro 430VS to burn a piston at ports (was my search)? I found some info below but doughty your piston looked like any of these (in the link).*

*Get a friend to post the picture and you will catch learn the process. I always find the Pics must be a reasonable size (1-2 qualities above email), like 1 meg or less vs the best your camera will take.*

*The idle issue might be a cable or connection issue.*


http://www.smellofdeath.com/lloydy/piston_diag_guide.htm


----------



## jow (Aug 16, 2012)

Take a pic or pics of bad piston and idle adjusting issue showing cable connection and adj screw and plate (as much as possible in good clear Pics. Send them to a trusted friend to post attachments and someone will possibly spot issues.


----------



## milliesdad (Nov 11, 2013)

Found the problem with the idle adjustment.Some were someone cross threaded it.

I worked a little magic and it idles perfectly. Carb should still come apart for a cleaning, but will wait until the endless winter is over for that. 

I can find a vac attachment kit for about $50.00 (one of the on-line small engine parts suppliers). If anyone k nows of a used around somewhere, please let me know.


----------



## jow (Aug 16, 2012)

A Good Find on the idle.
A good quick carb inspection/cleaning might save you another piston (with ref to running lean from restrictions).
A little info from the link below: 
Good Luck! Talk to a 2cycle mechanic (showing the piston) before you run too long. 



http://store.chainsawr.com/blogs/tuning-and-repairs/1126042-adjustment-and-tuning-of-a-chainsaw-carburetor


Carburetor adjustment is critical on chain saws and other two-cycle engines. An adjustment that is too rich will cause a saw to smoke, have insufficient power, result in additional carbon build up and may damage the engine. An adjustment that is too lean will also produce insufficient power and is more likely to damage the engine through lean seizure. The correct carburetor adjustment will allow the saw to produce maximum power, extend the duty cycle of the engine, produce minimal smoke, idle smoothly, rev up nicely and give trouble free service.


An over rich carburetor adjustment is when the proportion of fuel in the combustible air/fuel mixture is so high that the fuel does not burn well. The burn does not produce much heat, so the power stroke is weak. The partially burned mixture is expelled into the muffler and exits the saw as smoke. An over rich condition causes carbon buildup and will plug the fire screen and cylinder ports if run for a period of time. Outside of carburetor adjustments this can also be caused by having too much oil mixed with the fuel, and/or old stale gasoline.


A lean carburetor adjustment is when the proportion of fuel in the combustible air/fuel mixture is so low that there is not enough fuel to burn. This also makes a weak power stroke and causes the saw to have insufficient power. In addition to low power, a lean condition causes the cylinder temperature to rise, which often leads to seizure. A lean condition also allows for excessive RPM which often leads to big end rod bearing failure. Other causes for a lean running condition include lack of oil in the fuel mix, and when the fuel tank runs empty. Always stop a saw before the tank runs completely dry. Be sure to use the correct gasolineil 
mixture ratio recommended for your chainsaw.


More good info and Pic examples at this address:

http://www.poweredparaglider.com.au/_ParaToys/Engines/Burnt-out_Piston.html


----------

