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LoveToFly1 · 11-18-2015, 09:30 AM

i have had this happen 5 times now. ranging from 20 gallons, to 2 tanks. I can tell immediately at this point when it happens by the way the motor is running. there are a few things that contribute, I think they are aware of it now. the last thing you want to do it put a solid pin in its place though IMO. heath expansion is drastically different from hardened steel and aluminum. I think the issue arose when O.S. moved their factory from japan to china.

cmouton · 11-19-2015, 10:11 AM

My OS105 fly great after the solid pin mod to the piston. No problems doing that for me. But it must be done by a professional.

If OS don't fix the problem, I will go for a YS.

I really got fed up with my OS105. The last time the failing pin ruined a brand new sleeve, piston ring and piston. I was still busy with breakin. I had less than 5 tanks through it.

The OS suppliers in our country did nothing and ignored my emails.

I send them numerous emails complaining about the pin in the piston failing. I just gave up on them.

That's when I searched on helifreak and came across "sirolfs" thread and decided to do the same as I were desperate. It worked like a charm.

I really hope OS support are better in other countries.

Sirolf · 11-22-2015, 06:33 AM

OS will not help you even if you have tons of evidence backing it up.
Believe me i also bombarded OS with emails.

They claim it is from running lean... period.
Like talking to a wall.

Do the mod and you won't have to worry about it anymore.
I'm having a spare piston done right now.

msallua · 11-25-2015, 05:25 AM

Hi .

I found this in Amazon , if the picture is OK, now the piston ring pin comes from top to bottom.

Part Number 28703200

http://www.amazon.com/Engines-287032.../dp/B007UQXFO0

Delarado · 11-26-2015, 05:46 AM

Quote:

Originally Posted by msallua

Hi .

I found this in Amazon , if the picture is OK, now the piston ring pin comes from top to bottom.

Part Number 28703200

Amazon.com: O.S. Engines 28703200 Piston for 105HZ Engine: Toys & Games

What make syou say that? looks like a standard piston to me, the holes in the top are there on all of them.

abit late · 11-27-2015, 11:24 AM

Looks like the piston pin runs vertically. Click on the image and zoom in.

msallua · 11-27-2015, 12:00 PM

Quote:

Originally Posted by abit late

Looks like the piston pin runs vertically. Click on the image and zoom in.

+1

cmouton · 11-27-2015, 02:29 PM

You see the light through the hole on top. It's not a vertical pin. If that were really the pin, then it was also located at the wrong place.

Have a look at a 105 piston and you will see what I mean.

Sirolf · 11-29-2015, 10:51 AM

Yep... it looks like a vertical pin if it is what you would want to see.
Only the gasser GT15 had the same problem and they where replaced with these vertical pins.

cabeng · 11-30-2015, 07:39 AM

What you see there is a lack of a shadow where the hole in the top of the piston is to put pressure on the ring improving the seal , that is the std piston in the pic , sadly OS yes to look at the problem!

Danny Dugger · 01-20-2016, 05:30 PM

Hey guys I received a new 105 piston from RC Japan today and it's got a solid pin!!!! Looks like OS was listening

:thumbup

msallua · 01-20-2016, 05:32 PM

Quote:

Originally Posted by Danny Dugger

Hey guys I received a new 105 piston from RC Japan today and it's got a solid pin!!!! Looks like OS was listening

:thumbup

Steve Graham · 01-20-2016, 11:30 PM

very good news indeed

dbcaster · 01-21-2016, 07:27 PM

That is great news. Hopefully the new engines will come this way as well.

blue92ehsi · 01-22-2016, 10:25 AM

so much for "we are unaware of any pin related issues" lol I'll order one down the road once more people get them

msallua · 01-22-2016, 10:38 AM

Danny Dugger, the item has a special part number or is the same?

Please, Can you share with us the link in the website ( Rcjapan) of this part?

Thanks in advance

Danny Dugger · 01-22-2016, 01:22 PM

Quote:

Originally Posted by msallua

Danny Dugger, the item has a special part number or is the same?

Please, Can you share with us the link in the website ( Rcjapan) of this part?

Thanks in advance

Same part number

https://rcjapan.net/o-s-engine-parts...bbvj1tle4qjjd2

marc8090 · 01-22-2016, 10:22 PM

I voted less than 20 gallons with no problem. I have 2 of these, went through 36 gallons this past season split equally between two helis, so 18 gallons without issue. Took engines apart, everything looks great. Rebuilding anyway, and just ordered new pistons from RC Japan a couple days ago. After seeing the above post about the solid pin, I will let you guys know what I get when my new parts arrive.

dbcaster · 01-22-2016, 11:28 PM

I ordered a new 105 yesterday. I will also post on the piston once it arrives.

Sirolf · 01-23-2016, 02:58 AM

Hope to see this with 91hz pistons also...

View Poll Results: Which of the following is true?
I have an OS105, the pin has always been fine and my engine has less than 10 gallons	7	21.21%
I have an OS105, the pin has always been fine and my engine has more than 10 gallons	2	6.06%
I have an OS105, the pin has always been fine and my engine has less than 20 gallons	7	21.21%
I have an OS105, the pin wore through before 10 gallons were through	9	27.27%
I have an OS105, the pin wore through between 10-20 gallons	6	18.18%
I have an OS105, the pin wore through after 20 gallons	2	6.06%
Voters: 33. You may not vote on this poll

11-18-2015, 09:30 AM	#21 (permalink)
LoveToFly1 Registered Users Join Date: Jun 2013	i have had this happen 5 times now. ranging from 20 gallons, to 2 tanks. I can tell immediately at this point when it happens by the way the motor is running. there are a few things that contribute, I think they are aware of it now. the last thing you want to do it put a solid pin in its place though IMO. heath expansion is drastically different from hardened steel and aluminum. I think the issue arose when O.S. moved their factory from japan to china. __________________ Gasser Mike Team KDE Direct, TRM Power, Byron Fuels, MKS Servos

11-19-2015, 10:11 AM	#22 (permalink)
cmouton Registered Users Join Date: Mar 2011	My OS105 fly great after the solid pin mod to the piston. No problems doing that for me. But it must be done by a professional. If OS don't fix the problem, I will go for a YS. I really got fed up with my OS105. The last time the failing pin ruined a brand new sleeve, piston ring and piston. I was still busy with breakin. I had less than 5 tanks through it. The OS suppliers in our country did nothing and ignored my emails. I send them numerous emails complaining about the pin in the piston failing. I just gave up on them. That's when I searched on helifreak and came across "sirolfs" thread and decided to do the same as I were desperate. It worked like a charm. I really hope OS support are better in other countries. __________________ Align T-Rex 600&700 Nitro Pro DFC SAB Goblin 630 Competition SAB Trioblin 500 Futaba 8FG Super

11-22-2015, 06:33 AM	#23 (permalink)
Sirolf Registered Users Join Date: May 2009	OS will not help you even if you have tons of evidence backing it up. Believe me i also bombarded OS with emails. They claim it is from running lean... period. Like talking to a wall. Do the mod and you won't have to worry about it anymore. I'm having a spare piston done right now. __________________ KDS Chase 360 \| Align Trex 600NSP \| Align Trex 700E \| Align Trex 700X

11-25-2015, 05:25 AM	#24 (permalink)
msallua Registered Users Join Date: Nov 2010 Location: Doral, Florida, USA	Hi . I found this in Amazon , if the picture is OK, now the piston ring pin comes from top to bottom. Part Number 28703200 http://www.amazon.com/Engines-287032.../dp/B007UQXFO0 Attached Thumbnails __________________ Align 800e PRO DFC // KRAKEN Yellow // RAW Nitro // Align 700N DFC // RAW Yellow // 2x Goblin 420 // RAW 420 // RealFlight 7.5 // neXt // AccuRc // Tribunus - Vbar Control Touch - Vbar Neo

11-27-2015, 11:24 AM	#26 (permalink)
abit late Registered Users Join Date: Feb 2008	Looks like the piston pin runs vertically. Click on the image and zoom in.

11-27-2015, 02:29 PM	#28 (permalink)
cmouton Registered Users Join Date: Mar 2011	You see the light through the hole on top. It's not a vertical pin. If that were really the pin, then it was also located at the wrong place. Have a look at a 105 piston and you will see what I mean. __________________ Align T-Rex 600&700 Nitro Pro DFC SAB Goblin 630 Competition SAB Trioblin 500 Futaba 8FG Super

11-29-2015, 10:51 AM	#29 (permalink)
Sirolf Registered Users Join Date: May 2009	Yep... it looks like a vertical pin if it is what you would want to see. Only the gasser GT15 had the same problem and they where replaced with these vertical pins. __________________ KDS Chase 360 \| Align Trex 600NSP \| Align Trex 700E \| Align Trex 700X

11-30-2015, 07:39 AM	#30 (permalink)
cabeng Registered Users Join Date: Nov 2012	What you see there is a lack of a shadow where the hole in the top of the piston is to put pressure on the ring improving the seal , that is the std piston in the pic , sadly OS yes to look at the problem!

01-20-2016, 05:30 PM	#31 (permalink)
Danny Dugger Registered Users Join Date: Aug 2012	Hey guys I received a new 105 piston from RC Japan today and it's got a solid pin!!!! Looks like OS was listening :thumbup

01-20-2016, 11:30 PM	#33 (permalink)
Steve Graham Registered Users Join Date: Feb 2008	very good news indeed

01-21-2016, 07:27 PM	#34 (permalink)
dbcaster Registered Users Join Date: Jul 2005	That is great news. Hopefully the new engines will come this way as well.

01-22-2016, 10:25 AM	#35 (permalink)
blue92ehsi Registered Users Join Date: Apr 2013	so much for "we are unaware of any pin related issues" lol I'll order one down the road once more people get them

01-22-2016, 10:38 AM	#36 (permalink)
msallua Registered Users Join Date: Nov 2010 Location: Doral, Florida, USA	Danny Dugger, the item has a special part number or is the same? Please, Can you share with us the link in the website ( Rcjapan) of this part? Thanks in advance __________________ Align 800e PRO DFC // KRAKEN Yellow // RAW Nitro // Align 700N DFC // RAW Yellow // 2x Goblin 420 // RAW 420 // RealFlight 7.5 // neXt // AccuRc // Tribunus - Vbar Control Touch - Vbar Neo

01-22-2016, 10:22 PM	#38 (permalink)
marc8090 Registered Users Join Date: Sep 2006	I voted less than 20 gallons with no problem. I have 2 of these, went through 36 gallons this past season split equally between two helis, so 18 gallons without issue. Took engines apart, everything looks great. Rebuilding anyway, and just ordered new pistons from RC Japan a couple days ago. After seeing the above post about the solid pin, I will let you guys know what I get when my new parts arrive.

01-22-2016, 11:28 PM	#39 (permalink)
dbcaster Registered Users Join Date: Jul 2005	I ordered a new 105 yesterday. I will also post on the piston once it arrives.

01-23-2016, 02:58 AM	#40 (permalink)
Sirolf Registered Users Join Date: May 2009	Hope to see this with 91hz pistons also... __________________ KDS Chase 360 \| Align Trex 600NSP \| Align Trex 700E \| Align Trex 700X

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