# stihl ms290 Farm Boss new china cylinder



## rippinryno (Nov 24, 2015)

Well i picked up a stihl ms290 in very good condition for $125, it had a cracked piston.

I was nervous to pay so much for a busted motor, but am mechanically inclined so I decided to do the china build.

I put a piston and cylinder from Russo (ebay) in it.  So far so good, i've run the saw for about an hour and things are looking good.  I will attach a photo of the new cylinder and piston.

for the price of Stihl replacement parts I was going to be looking at more investment than a new saw costs.  In this case I was able to get this thing completely rebuilt and up and running for $170ish, completely worth it to me.

I see many people on this forum shun the china kits, and i also see many who just don't even recommend them.  I would like to ask how many have experience puting these kits in?  I've used them on several different engines and builds and while they may not be the best for a race application, i think on these small 2 strokes they are a great alternative at a fraction of the cost!

I also used a little trick to get the piston in the cylinder without the need for the special tool. Put piston in cylinder, then put the pin through connecting rod while piston is already in the cylinder.....piece of cake!


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## jeffesonm (Nov 24, 2015)

interested to hear how you make out with it


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## dougand3 (Nov 24, 2015)

I've used 4 FarmerTec top ends for the Husky 55. They run great with good compression. No matter which China retailer (Huztl, wangluo18, machinedoctors, etc) you order from, it will probably be the same kit and take 10-14 days to arrive. If you want it quicker, use US retailers - Russo, DRZsmallparts, HLSupply. I'm guessing there is 1 factory that makes them with dozens of retailers. So many China ordered parts come in a FarmerTec box.


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## rippinryno (Nov 24, 2015)

yeah this actually came in a farmertec box.  i'm glad to hear you've had them work well too.  I am mostly suprised to see so many people on here straight up telling folks not to use it and "you get what you pay for".  The problem lies with people stating such things without having any personal experience with them.  To revive a saw, for $40, it's more than worth it!  I  will be using mine this afternoon for a couple hours and plan to use it for years to come.


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## Timberwolf530 (Nov 24, 2015)

You have to remember that a lot of the guys who are telling you to avoid them use their saws on a daily basis.  For someone who uses one a couple times a year, probably not a big deal, but for every day use they probably wear out much quicker.


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## Jon1270 (Nov 24, 2015)

I've installed one Hyway and one Raisman kit after reading good reviews of each.  I use meteor pistons regularly.  Only once have I bought a new OEM cylinder kit: to convert a Makita 6401 to a 7901.  I have bought a couple of used OEM cylinders.

I have seen what seems like a high rate of failure in aftermarket top ends of unknown brand, installed by other people.  I've seen one plating failure that killed a saw after about 15 minutes' use, and I've seen one piston that shattered after less than a year of commercial use. 



Timberwolf530 said:


> You have to remember that a lot of the guys who are telling you to avoid them use their saws on a daily basis.



Yes, and some are just enthusiasts who expect to eventually sell the saws they fix, to finance the purchase of the next shiny thing. For someone who does that regularly, reputation is more valuable than any particular saw, and one is disinclined to risk it.


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## Timberwolf530 (Nov 24, 2015)

"Yes, and some are just enthusiasts who expect to eventually sell the saws the fix, to finance the purchase of the next shiny thing. For someone who does that regularly, reputation is more valuable than any particular saw, and one is disinclined to risk it."

Great point!!


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## rippinryno (Nov 24, 2015)

I don't use mine commercially but I have got great life out of these Pistons.  The plain and simple is that when they are installed correctly they are not lacking.  The mark up on your stihl brand top ends is huge!  I use my saws a good amounT.

Why would somebody put hundreds into a saw that they will resell to fund another purchase?  Seems the China top ends would be ideal for this.  Otherwise if you spend $175 on a stihl kit you might as well not plan on selling it.

I don't see them failing any faster when proper install and maintenance is done.


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## jrems (Nov 25, 2015)

I have used these kits a few times and they were used commercially. They aren't bad, they do lack the precise fit and finish of the stihl parts. If you spend 30 minutes rounding the sharp port edges and piston, and check clearances ( a few needed 2 base gaskets) it should last much longer in most cases.


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## rippinryno (Nov 25, 2015)

On the 290 I just put some rtv on base like they had from the factory.  I did notice these don't have the groove on the base like the stihl cylinder did.  I left my ports knife edged as the stihl components were not rounded either.  I could go into philosophies as to why knife edge is sometimes better but that will take forever and really only refers to the race engines I've built.


Another thing that i dont' see much of when people are talking down to these cylinders it's usually that they fail sooner and don't last very long, but the fact is, and you can't deny it.  These things can be finicky and even a stihl brand rebuild can fail.  I am not convinced that the failure rate is any sooner with these aftermarket pistons.  I could be wrong, but I have not had one fail on me yet.


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## rippinryno (Dec 1, 2015)

Cut up an entire maple the past week or so with the rebuilt stihl and it didn't give me a hiccup.


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## computeruser (Dec 1, 2015)

rippinryno said:


> Why would somebody put hundreds into a saw that they will resell to fund another purchase?  Seems the China top ends would be ideal for this.  Otherwise if you spend $175 on a stihl kit you might as well not plan on selling it.
> 
> I don't see them failing any faster when proper install and maintenance is done.



A couple thoughts:

Your potential market on resale will be much smaller on a saw with non-OEM parts, particularly for higher-end, higher-performance saws.  Finding a used cylinder and either putting an OEM piston or high-quality aftermarket piston (e.g. Meteor) will leave you much better off for resale.

There is also the issue of the kit's design - port timing, port volume, quality control (in the sense of plating, port bevel, interior port finish, squish, etc.) - which are rarely identical to OEM.  On a lower compression, lower performance saw, this might not make a difference that most users will notice.  But on a lot of saws, it will.

Even the OEMs change port timing, ignition settings, and other details over the lifecycle of their products.  This is why the early Stihl 044 with the 10mm piston pin and KS cylinder, or the early Stihl 066 with the metal flywheels and early cylinders, have a particular performance advantage and command a premium.  Slapping an aftermarket piston and cylinder on the crankcase of one of these saws does restore it to new.


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## rippinryno (Dec 1, 2015)

Suggesting a used cylinder and piston for a saw is no good.  I don't care who thinks it is a good idea I don't.  I refuse to do something like that. If it was the entire motor then maybe....I could sell this saw for what I have in it very easily.  It runs like a top.  The design of this piston and cylinder is very near identical.  Since no one cylinder and piston are the same this is all relative.  How many have you installed or seen first hand?just curious since ive personally dealt with many of them and speak from that experience.  Compression is a good topic.  What saws are u referring to that are a higher compression and what octane do you run in them?

I also want to point out that resale on this saw has gone up drastically since before i put a $30 rebuild kit in it.  So, you go from a burnt up non running stihl that's worth very little, to a perfectly running non oem replacement top end stihl.  YOu do the math, i'm sure i could easily get $200 out of this saw, however my intention is not to sell it, it runs too good!


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## NoPaint (Dec 1, 2015)

rippinryno said:


> Suggesting a used cylinder and piston for a saw is no good.  I don't care who thinks it is a good idea I don't.  I refuse to do something like that. If it was the entire motor then maybe....I could sell this saw for what I have in it very easily.  It runs like a top.  The design of this piston and cylinder is very near identical.  Since no one cylinder and piston are the same this is all relative.  How many have you installed or seen first hand?just curious since ive personally dealt with many of them and speak from that experience.  Compression is a good topic.  What saws are u referring to that are a higher compression and what octane do you run in them?



And you are 100% not affiliated with any of these chinese parts sellers?


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## rippinryno (Dec 2, 2015)

Correct.  My previous post may have come off a bit rude.  My main point was that a used piston and cylinder really are not a good option in my opinion.  Tight tolerances and a rebuild with used parts typically don't tend to last very long.  I really posted this thread not to advertise china cylinders as some may think, but to offer a thread from somebody who's used them with good results.  I have read many a thread on this forum where people simply turn their nose or do not suggest them.  My concern is how many of these folks actually test or use them?  How many have they had fail?  These are oem replacement cylinders and are manufactured to the same specs.  Sure you might find a bad apple in the bunch but a simple caliper check and look over can prevent installing a bad.  I personally have not seen a bad one.  If I was building a high compression race gas motor with huge investment, sure I'd buy the name brand, but when it comes to these simple little motors that are not running 110 octane race fuel with huge CR's, i think these kits can last a long time.  I would like to know what the previous guy was referring to with a high compression stihl motor, im' not aware of any that require anything more than 87 octane, but i could be wrong, also even a slight variance in port volume can be made up for in carb adjustments, although this one did not require a single adjustment except to turn the idle just a tad after break in.

Another good reason to buy entire kit instead of replacing just a piston is exactly like was mentioned, some of the older saws actually have different size piston and pins even!  why take the risk when you can get the whole kit.  Early 029's had a 45mm piston, this newer (not new though) 290 has a 46mm piston with a 45.95 bore, the kit i bought is a direct replacement of that.  meteor would be the exact same thing i'm certain and i can't vouch for it being that much better.

here is the exact kit that i purchased and have had good luck with.  http://www.ebay.com/itm/301736505499?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT


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## computeruser (Dec 2, 2015)

Sounds like you don't have a lot of experience in the saw building game.  That's fine.  But please trust that running a new piston/rings in a used OEM cylinder is both common and advisable when compared to an aftermarket unit.  It is completely reasonable to rebuild commercially-run saws with new piston/rings at least a couple times during the lifetime of the crankcase, crank bearings, and cylinder.

Please also be aware that the considerations I mentioned - port timing, volume, shape, flow characteristics, squish, and so forth - are factors inherent in the physical design and machining of the cylinder, and cannot be "made up for in carb adjustments."  My point wasn't that AM won't run, but that it often won't run as well as the OEM setup did.

Regarding compression, you'll find that a lot of these AM kits end up with squish figures that are all over the place and often very large - .060"+, even - and that this level of variability makes for very different, inconsistent outcomes.  Some can be cured by running without a base gasket, but others by their design leave you without any recourse, such as in the case of clamshell engines like that of the 290.  The simple truth is that you are not, because you cannot, going to make good compression with that much squish.  Enough to run, maybe even to run OK, but you're needlessly leaving a lot of potential on the table.

By way of example, I built an 044 (10mm, KS cylinder) a few years back that came in at .019" squish w/o base gasket and pulled 185psi.  It ran really, really strong without any porting work.  I can guarantee you that an AM piston/cylinder on that saw, with some crazy .040"+ squish and less aggressive porting with ugly transfers, would have been noticeably weaker.  Even the later Stihl OEM cylinders routinely make less power, which is why some of these earlier OEM cylinders remain desirable 20+ years after they were last sold new.

I do not disagree with your premise that AM kits are a viable option for many users.  But I do not think it does folks any service to suggest that they are the same as, or equal to, the OEM offerings and that OEM is per se overpriced.  Each option - OEM or AM - represents a particular trade-off, and people should be given the facts they need to make that choice when rebuild time comes.


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## rippinryno (Dec 2, 2015)

computeruser said:


> Regarding compression, you'll find that a lot of these AM kits end up with squish figures that are all over the place and often very large - .060"+, even - and that this level of variability makes for very different, inconsistent outcomes.  Some can be cured by running without a base gasket, but others by their design leave you without any recourse, such as in the case of clamshell engines like that of the 290.  The simple truth is that you are not, because you cannot, going to make good compression with that much squish.  Enough to run, maybe even to run OK, but you're needlessly leaving a lot of potential on the table.



Which is why you deck the cylinder to compensate for an improper squish, are you familiar with this method? Certainly you are not left without recourse unless you're simply not aware of this practice.  My cylinder actually matched nearly perfect to Oem.



computeruser said:


> Please also be aware that the considerations I mentioned - port timing, volume, shape, flow characteristics, squish, and so forth - are factors inherent in the physical design and machining of the cylinder, and cannot be "made up for in carb adjustments."  My point wasn't that AM won't run, but that it often won't run as well as the OEM setup did.


Port timing volume and shape can all be tuned with the carb.  It is actually starting to sound like you dont' know much about building motors, that's fine as well.  I've ported more two stroke cylinders than any other motor.  You obviously can't fix a bad part but you can improve and tune very easily on a weak design.  None of which I've needed with am kits.

How many am kits have you run?  How many have you found to vary as much as you describe?



computeruser said:


> Sounds like you don't have a lot of experience in the saw building game.  That's fine.  But please trust that running a new piston/rings in a used OEM cylinder is both common and advisable when compared to an aftermarket unit.  It is completely reasonable to rebuild commercially-run saws with new piston/rings at least a couple times during the lifetime of the crankcase, crank bearings, and cylinder.


Typically if a piston and rings are worn out the cylinder will show wear, Even a nikisil plated one will need cleaned up.  You can over bore or you can replace.  If it's not that bad then sure a piston replacement will suffice.  I've not seen many small 2 stroke engines that needed only a piston and rings.....they tend to eat up the cylinder as well.  Can you put a new piston in used cylinder, sure, but without a hone or re-bore, you're likely not going to get the full life out of it.

I completely understand that there can and will be less of a quality control on such a mass produced cheap cylinder, however these are typically designed to OEM spec, and It's all to common for people to assume they just aren't sufficient.  In fact they truly are in most cases.


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## wpgibson (Dec 9, 2015)

I have a 290 with 2 rebuilds under warranty in the first 12 months. I found this whole thread helpful, since the next rebuild (hopefully never) will be on me.

So, a simple thank you.







rippinryno said:


> Correct.  My previous post may have come off a bit rude.  My main point was that a used piston and cylinder really are not a good option in my opinion.  Tight tolerances and a rebuild with used parts typically don't tend to last very long.  I really posted this thread not to advertise china cylinders as some may think, but to offer a thread from somebody who's used them with good results.  I have read many a thread on this forum where people simply turn their nose or do not suggest them.  My concern is how many of these folks actually test or use them?  How many have they had fail?  These are oem replacement cylinders and are manufactured to the same specs.  Sure you might find a bad apple in the bunch but a simple caliper check and look over can prevent installing a bad.  I personally have not seen a bad one.  If I was building a high compression race gas motor with huge investment, sure I'd buy the name brand, but when it comes to these simple little motors that are not running 110 octane race fuel with huge CR's, i think these kits can last a long time.  I would like to know what the previous guy was referring to with a high compression stihl motor, im' not aware of any that require anything more than 87 octane, but i could be wrong, also even a slight variance in port volume can be made up for in carb adjustments, although this one did not require a single adjustment except to turn the idle just a tad after break in.
> 
> Another good reason to buy entire kit instead of replacing just a piston is exactly like was mentioned, some of the older saws actually have different size piston and pins even!  why take the risk when you can get the whole kit.  Early 029's had a 45mm piston, this newer (not new though) 290 has a 46mm piston with a 45.95 bore, the kit i bought is a direct replacement of that.  meteor would be the exact same thing i'm certain and i can't vouch for it being that much better.
> 
> here is the exact kit that i purchased and have had good luck with.  http://www.ebay.com/itm/301736505499?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT


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## rippinryno (Dec 9, 2015)

glad you got some pointers.  as stated even the stock components can fail, they are fiesty little motors in general but i would hope your 2nd rebuild will last you a long time before you need to consider a china option.


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## dougand3 (Dec 9, 2015)

What were the diagnoses on 2 rebuilds in a year?


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## wpgibson (Dec 13, 2015)

Bad batch of wrist pin springs scored the original engine as well as the replacement. (If I recall correctly)

The replacement went up within 10 minutes and went right back to the shop.


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## rippinryno (Dec 13, 2015)

The circlips?


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## jrems (Dec 13, 2015)

I posted earlier and I completely agree that the oem is no doubt better quality. From my experience if the aftermarket parts are fine tuned( casting marks and ports smoothed, edges deburred,etc,,,) you can have a decent running saw at minimal cost, just some extra labor. These chinese rebuild kits are not for everyone. I have seen some really sharp port edges as well as casting flaws in the exhaust port, if these were not fixed the saw would have a much shorter life. some of these kits if they were installed as is, they would not last nearly as long as an oem kit.


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## rippinryno (Dec 13, 2015)

claydogg84 said:


> Seems strange that you joined this forum and immediately pushed your agenda on this subject. You've gone as far as becoming flat out confrontational towards those who don't completely agree. Aftermarket rebuilds are not equal in terms of quality, compared to OEM - And I say that without giving 2 shits about your "Race Engines". There's no chance that eBay link would be your listing, is there?



Please do not accuse me.  That eBay listing is not mine nor do I have any relation to the seller or any Seller of Chinese replacement parts.

Why does it seem strange and why do you think I'm pushing an agenda?  I was clear on my intentions of sharing my results about aftermarket kits....as I mentioned,  after reading a few threads about it there is a common trend of people saying not to use them, I wanted to give my first hand opinion based on experience.

I've not seen them lacking and at the price point they are a very good option and when done correctly they can hold up very well.


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## claydogg84 (Dec 13, 2015)

rippinryno said:


> Please do not accuse me.  That eBay listing is not mine nor do I have any relation to the seller or any Seller of Chinese replacement parts.
> 
> Why does it seem strange and why do you think I'm pushing an agenda?  I was clear on my intentions of sharing my results about aftermarket kits....as I mentioned,  after reading a few threads about it there is a common trend of people saying not to use them, I wanted to give my first hand opinion based on experience.
> 
> I've not seen them lacking and at the price point they are a very good option and when done correctly they can hold up very well.



Join a forum, announce how great a product is, provide a direct link to said product, and then become confrontational when someone disagrees with your statements. This doesn't sound a bit off to you? The aftermarket kits are great for lower end "throwaway" saws. As far as a professional, high end saw, I wouldn't use an anything but OEM unless the saw was extremely beat up.


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## fossil (Dec 13, 2015)

Go get a pizza and a couple of beers and talk about something other than chainsaws for while.


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