# Poulan BVM210 blower woes



## ebleas (Dec 24, 2013)

Hi all. I bought a used Poulan blower off EBay for 20 bucks, as I wanted a fixer-upper to learn about 2-cycle engines. I have successully rebuilt a few 4-cycle Briggs from lawn mowers in the past, and wanted to venture into the land of 2-stokes. Got it, and of course it would not start (surprise). So, here's what I have done so far:

- Took apart the carb and gave it a good cleaning. The small filter/screen inside was fairly clogged.
- Tested spark with a spark tester. I get a good blue color jumping the gap.
- I noticed the filter had broken off the tube inside the tank, and was probably run this way for awhile by the previous owner. Put new gas lines on and reconnected the fuel filter.
- Cleaned the air filter.
- Pulled the cover off that covers the impeller. If I turn the impeller backwards, I get good resistance and it jumps back when I release the hold. This tells me I have pretty good compression in the engine.
- Took off the muffler assembly and looked into the cylinder. I did not see any obvious scoring.

After all this tried to start it up again. Nothing. Not even a cough or sputter. ( I did follow the proper prime/start sequence.) Moved the two adjustment screws all the way in and then backed them out 1 and a half turns to try to set these to some known state in case they were way off. Still nothing.

I noticed that when I prime it with the bulb, there seems to be air sucked back up the prime line (side where the fuel is dispensed back into the tank) when I release the bulb, but the bulb does fill about half-way with the fuel mixture. I thought there was some type of check value in this primer side that prevented air coming back up? Does this indicate the seals in the carb need replacement (they looked OK when I took it apart)? I took the cover of the crankcase off and notice that there was a significant amout of fuel mix in the crankcase under the piston. Is this normal? I though the piston ring prevented the fuel from leaking down into the crankcase? Is this a possible piston ring problem? My arm is sore and I'm getting frustrated. Where should I go next? New carb, pull off the piston and put a new ring on? Thanks all in advance. :wave:


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## geogrubb (Jul 28, 2006)

ebleas said:


> Hi all. I bought a used Poulan blower off EBay for 20 bucks, as I wanted a fixer-upper to learn about 2-cycle engines. I have successully rebuilt a few 4-cycle Briggs from lawn mowers in the past, and wanted to venture into the land of 2-stokes. Got it, and of course it would not start (surprise). So, here's what I have done so far:
> 
> - Took apart the carb and gave it a good cleaning. The small filter/screen inside was fairly clogged.
> - Tested spark with a spark tester. I get a good blue color jumping the gap.
> ...


Make sure the bolts holding the cylinder on are tight, these blowers have a tendency for them to come loose, next check the compression using a compression tester, it needs at least 90 lbs to run. have a good one. Geo


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## Rentahusband (Aug 25, 2008)

I would follow Geo's advice, then try starting again.
A good cleaning on these carbs does not always solve the problem. There is a metering diaphragm that can also cause problems due to being stiff or a pin hole in the material. Usually it is due to being stiff. You can get a rebuild kit. These range from $10-$15 or a new carb which is around $30. I would suggest a new carb. I find it is worth replacing the carb vs installing a kit depending on the price difference and for $15 more, it is easier to go with the new carb. You should have either a Zama or Walbro carb. There will also be a model # stamped on the carb. Ebay or ereplacementparts.com are good places to look.


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## Sir Thomas (Dec 7, 2013)

ebleas said:


> Hi all. I bought a used Poulan blower off EBay for 20 bucks, as I wanted a fixer-upper to learn about 2-cycle engines. I have successully rebuilt a few 4-cycle Briggs from lawn mowers in the past, and wanted to venture into the land of 2-stokes. Got it, and of course it would not start (surprise). So, here's what I have done so far:
> 
> - Took apart the carb and gave it a good cleaning. The small filter/screen inside was fairly clogged.
> - Tested spark with a spark tester. I get a good blue color jumping the gap.
> ...


You have probably made same mistake that i did. Some carb cleaners are not good for Zama or Walbro Carbs. Is the Primer body attached to the carb? With the hose attached, gently blow in and out. If it is functioning properly, it should only blow one way. Somehow the check valve inside the Primer Body (which is not replacable) is damaged. If you take the Primer Body off, hold the body itself up to a light and look through the two holes. If you see light, there's your problem. Like the others said buy a new carb or look for a used one that works. Do you have anything to check the compression? You should have at least 75-90 psi of pressure. If you pull the cylindar off, use a solf pencil eraser or toothbrush handle and push against the ring. If it doesn't move in and out, it may be froze in the landing. Get some Seafoam cleaner and let it soak. The resistant you feel may be the magnet on the flywheel. Even with the flywheel off, at 40 to 45 psi you'll feel some resistant but that's not enough compression.
I didn't know all this before joining the forum but I went down the same path you did.


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## ebleas (Dec 24, 2013)

Thanks all for the replies! I got an Actron compression tester, and it is reading about 70 PSI maximum. From what I've read, this is insufficient to maintain combustion on these engines? I plan to pull off the head and replace the piston ring. How does this come off? I take off the two bolts that hold the head on, and then lift the head off over the piston / ring?


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## Sir Thomas (Dec 7, 2013)

ebleas said:


> Thanks all for the replies! I got an Actron compression tester, and it is reading about 70 PSI maximum. From what I've read, this is insufficient to maintain combustion on these engines? I plan to pull off the head and replace the piston ring. How does this come off? I take off the two bolts that hold the head on, and then lift the head off over the piston / ring?


There should be two bolts. If it's anything like mine, You'll need a long allen wrench. After you pull the head, check the condition of the rings and the cyclinder wall. Are either scored? Take a pencil, eraser side and push against the ring. If it moves in and out freely then it should be ok unless there scoring on the ring. If it doesn't move in and out freely then it is frozen in the land. Put the cyclindar back on, turn so the piston is at the top and spray through the spark plug hole some Seafoam Cleaner, let it soak and spray some more. Checking to see if it moves. If it does, take the ring off and clean the landing carefully.

If the engine is old and there's a possibility that someone has been running it without 2 cycle oil mixture or the wrong ratio and the ring is worn.


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## ebleas (Dec 24, 2013)

*Ring is stuck!*

I got the head off today. Not too bad, those bolts are hard to get to as others have mentioned. I had to use a long t-shaped allen wrench and put a socket over the short end and then put an extension bar on the socket to give me some leverage. The ring is frozen solid to the piston, and will not budge no matter how hard I push or pull. Tried to soak it in some carb cleaner, no luck. Tried to clean out the groove with a soft wire brush, soak again, still will not move. There is one long vertical scratch on the piston wall which is fairly deep (my fingernail will catch on it), other than that it was in good shape. The cylinder wall appeared to be in pretty good shape, I did not see any scoring. I might just splurge and get a new piston, ring, connecting rod assembly. I've seen them as low as $22.

Funny thing happened when I put it back together. I had used some SAE 30 weight oil to lube the cylinder wall when I put the piston back in. And when I tried to start it after assembly, it ran for a few seconds! Is this due to the oil adding some compression and allowing it to run for awhile until the oil burns off?


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## geogrubb (Jul 28, 2006)

ebleas said:


> I got the head off today. Not too bad, those bolts are hard to get to as others have mentioned. I had to use a long t-shaped allen wrench and put a socket over the short end and then put an extension bar on the socket to give me some leverage. The ring is frozen solid to the piston, and will not budge no matter how hard I push or pull. Tried to soak it in some carb cleaner, no luck. Tried to clean out the groove with a soft wire brush, soak again, still will not move. There is one long vertical scratch on the piston wall which is fairly deep (my fingernail will catch on it), other than that it was in good shape. The cylinder wall appeared to be in pretty good shape, I did not see any scoring. I might just splurge and get a new piston, ring, connecting rod assembly. I've seen them as low as $22.
> 
> Funny thing happened when I put it back together. I had used some SAE 30 weight oil to lube the cylinder wall when I put the piston back in. And when I tried to start it after assembly, it ran for a few seconds! Is this due to the oil adding some compression and allowing it to run for awhile until the oil burns off?


Short answer, YES it was because the oil filled the area usually filled with the rings and cylinder wall. Have a good one. Geo


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## Sir Thomas (Dec 7, 2013)

ebleas said:


> I got the head off today. Not too bad, those bolts are hard to get to as others have mentioned. I had to use a long t-shaped allen wrench and put a socket over the short end and then put an extension bar on the socket to give me some leverage. The ring is frozen solid to the piston, and will not budge no matter how hard I push or pull. Tried to soak it in some carb cleaner, no luck. Tried to clean out the groove with a soft wire brush, soak again, still will not move. There is one long vertical scratch on the piston wall which is fairly deep (my fingernail will catch on it), other than that it was in good shape. The cylinder wall appeared to be in pretty good shape, I did not see any scoring. I might just splurge and get a new piston, ring, connecting rod assembly. I've seen them as low as $22.
> 
> Funny thing happened when I put it back together. I had used some SAE 30 weight oil to lube the cylinder wall when I put the piston back in. And when I tried to start it after assembly, it ran for a few seconds! Is this due to the oil adding some compression and allowing it to run for awhile until the oil burns off?


So you have two things going on. The ring is frozen. Carb cleaner will not do it. Get some Seafoam Cleaner. Put the head back on and turn it until you see the piston at the top through the spark plug hole. Then spray Seafoam generously through the spark plug hole and let it sit. Do it several times. Pull the head and get a small rubber mallet that tap it all around. You might need to take a very small flat head screw driver and tap at the meeting edge of the ring.

And that score. If the ring is not scored, I don't think it would be a problem but I'd wonder how it got there.


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## ebleas (Dec 24, 2013)

*Success!*

I put the new piston / ring / rod assemble in, reassembled everything and tried to start it up. No luck. I noticed the primer was acting funny (sort of made a sound like it was sucking air and did not fill the bulb more than about quarter way up), and when I opened the fuel cap I got a hiss that seemed to be my breaking a vacuum build up. I noticed these caps have a vent hole, perhaps mine was plugged? I tried to clear the hole, reprimed (sounded better now), and then it started on first pull!! Ran it for about 15 minutes blowing the snow off my porch (hey, it's winter in Chicago), and seemed to purr like a kitten. SO, the moral of the story is - check the compression first, like others say.

One comment - it was a real pain to get the piston / ring assembly back in with no ring compressor (the ones I have for the briggs were way too big). I tried my best to line up the ring gap with the align pin on the piston, but with all the fiddling required to get it in, plus an extra set of hands (my wifes), who knows where the ring ended up relative to the pin. Would the ring even fit back into the cylinder if the ring gap was not aligned to the piston pin? Kind of has me worried now. Saw a piston compression kit on ebay for small engines and ordered it. I'll let you all know how it works.


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## Sir Thomas (Dec 7, 2013)

ebleas said:


> I put the new piston / ring / rod assemble in, reassembled everything and tried to start it up. No luck. I noticed the primer was acting funny (sort of made a sound like it was sucking air and did not fill the bulb more than about quarter way up), and when I opened the fuel cap I got a hiss that seemed to be my breaking a vacuum build up. I noticed these caps have a vent hole, perhaps mine was plugged? I tried to clear the hole, reprimed (sounded better now), and then it started on first pull!! Ran it for about 15 minutes blowing the snow off my porch (hey, it's winter in Chicago), and seemed to purr like a kitten. SO, the moral of the story is - check the compression first, like others say.
> 
> One comment - it was a real pain to get the piston / ring assembly back in with no ring compressor (the ones I have for the briggs were way too big). I tried my best to line up the ring gap with the align pin on the piston, but with all the fiddling required to get it in, plus an extra set of hands (my wifes), who knows where the ring ended up relative to the pin. Would the ring even fit back into the cylinder if the ring gap was not aligned to the piston pin? Kind of has me worried now. Saw a piston compression kit on ebay for small engines and ordered it. I'll let you all know how it works.


If the ring was not lined up with the piston pin, you wouldn't get it in at all and it definitly wouldn't run. Depending on how old it is, the primer bulb can get weak. I have one I need to replace. I'm assuming it's one mounted on the carb. 

Like you, I'm use to work on 4 cycles. A 4 cycle carb is straight up easy to work on. In order to make a 2 cycle to function in turned in any direction it has to be complicated. There are so many ports and channels that you have to make sure is clear, it's mind boggling.


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