Diesel Shakes?

I got this diesel 15 and the last time I ran it it shook so bad on the test stand it broke the needle valve. Could this be from the lack of ether? OBTW it a cheap Chinese Shin Jihn or something like that. Still have to use an electric starter to get it to fire off. It also ran without the needle valve but really rich! LMAO

Steven,
What kind (make) of engine, what size prop? what fuel mix?

Steel/Iron diesels usually vibrate a little more than a glow, but not that much.

Maybe you are just way rich and overcompressed, but I think it likely something hitting inside the engine. I'd suggest taking it apart and looking to see if the conrod is hitting the case, the crank hitting the conrod, and/or the piston hitting the backplate, or whatever. If you are having to start it with a starter, you proabably have poor piston/cylinder fit and maybe a leaking contrapiston. Hope this helps.

LAST EDITED ON Dec-24-03 AT 08:45 PM (CDT)
 
I've got a couple of those and I've only bench ran them but didn't notice any excessive vibration. Although if you look at the innards you'll notice there is nothing removed from the crank to improve balance. Of course my plain bearing PAW 19 is the same way. I was bench running a PAW 35 once and started getting a horrible vibration and it hadn't done so previously. I think I had a prop with a different pitch on each blade. Tried a different prop and the problem went away.
Shaking bad enough to break the NVA is really extreme though! On my Jin Shi 247 the pads the needle valve assembly sits on weren't machined parallel to each other so the NVA couldn't be securely installed. Mine vibrated loose the first time I ran it.

>I've got a couple of those and I've only bench ran them but
>didn't notice any excessive vibration. Although if you look
>at the innards you'll notice there is nothing removed from
>the crank to improve balance. Of course my plain bearing PAW
>19 is the same way. I was bench running a PAW 35 once and
>started getting a horrible vibration and it hadn't done so
>previously. I think I had a prop with a different pitch on
>each blade. Tried a different prop and the problem went
>away.

Hi Steve ,Hi Elwyn...I thing Elwyn is on the right track, I also have a couple of the Jin Shi's. I did the Carlson recommended mods on them and they run really well..14,800-15,300 rpm on an 8x4 test prop. I also have several Yin Yans(Silver Swallows) and a couple of C. S. versions, the Jin Shi's are the best performing by far. Steve, what fuel formula and what type and size prop are you using?? I hope your Jin Shi has had the recommended mods done...Because You will Ruin this engine if you use an electric starter...Sorry... this engine has to have a washer or shim to space the crankpin away from the backplate, it will gouge it otherwise. the other Carlson mod is to grind the crank web to facilitate dynamic balance. To be honest, It sounds like these modifications were not done to your engine; hence the vibes. Ed Carlson ( and I) consider the Jin Shi to be a Kit Engine.. Please give Ed Carlson a call at: 602-863-1684 I'll bet He'll help you if you killed the engine..also see his website: http://www.carlsonengineimports.com/ The Jin Shi is very CHEEP at $20.00-$25.00..depending on which way the wind blows. Ed is very willing to work with Diesel Maniacs....Tony Gallegos

No I got the engine from Carlson and did the mods he sugested. I nearly wore my arm out trying to get the thing to start, before I got out the starter. Now it just takes a simple bump of the starter to get it to fire. I'm running a 7-4 prop on it and it's running real rich with out the needle valve, so that could be the problem. I have a new needle valve assy from a Fox 35 in it as the holes in the venturi were so far out of alignment I had to ream the out to get a good needle valve assy seating.
As for fuel Its Davis diesel 1/2 A mix. I was really wondering if the lack of ether would cause rough running. Cause I got a can of John Deere waiting for the fuel! LOL

LAST EDITED ON Dec-26-03 AT 06:00 PM (CDT)
 
> I was really wondering if the lack of ether would cause rough running.

Normally, if you're short on ether, you can't get the engine started.
Be sure to check basics, like making sure your test prop is balanced.
A 7x4 is perhaps small for the engine. A 7.5x6 might be better.

Preston's right on about the fuel and prop. You might try 5" pitch, but 4" pitch is usually not enough for decent airspeed. Our website (below) has a link to the British Columbia D-Bat website, with lots of diesel tips. They have found that the Red Max diesel plainbearing mix is low on castor and low on ether, making starting and durability an issue with the typical PAW 2.5 single ball race engines. These have no sleeve in the front, just run steel crank on aluminum case. The Sharma has some followers, if you want a cheap diesel. Mel Lyne claims the Sharma are better made than the PAW's they are copied from, but with a fixed venturi, they don't take crashing as well. Carlson has them, I believe. Steve

>No I got the engine from Carlson and did the mods he
>sugested. I nearly wore my arm out trying to get the thing
>to start, before I got out the starter. Now it just takes a
>simple bump of the starter to get it to fire. I'm running a
>7-4 prop on it and it's running real rich with out the
>needle valve, so that could be the problem. I have a new
>needle valve assy from a Fox 35 in it as the holes in the
>venturi were so far out of alignment I had to ream the out
>to get a good needle valve assy seating.
>As for fuel Its Davis diesel 1/2 A mix. I was really
>wondering if the lack of ether would cause rough running.
>Cause I got a can of John Deere waiting for the fuel! LOL

Hi Steve, I've been thinking about the Vibe Problem some more and after the mods you performed, the engine should have smoothed out by quite a bit..I did encounter vibration when I went from an 8x4 prop to a cut down 8x4(7.5"x4")Taipan. the engine was in the 15,000+ rpm range. So I kept my props sizes bigger...figuring that the engine didn't like to go into that range. I have a Jin Shi on a Dumas Tomahawk(330sq") that flys beautifully on 60'X .015" lines. It uses a Taipan 9" x 4" prop. another source of vibration I've encoutered with some Silver Swallows and all my CS 2.49cc diesel engines is a loose fitting contra piston. I'm perplexed about your needle valve problem too. The Needles on all my Chinese engines run at approx 3.5 to 4 turns open. another mod I used, as suggested by Ed Carlson was to replace the stock venturi insert with a 6.5mm one from the Mvvs 2.0cc engine. Ed should still have these in stock. I do not know the fuel formula for your Davis 1/2A fuel; His fuel works okay I believe. I suggest the following formula: 35% Ether-20%Castor-1.5%Amynitrate, and the rest Kerosene. Red Max will mix this fuel for you. We have used this formula for over a decade(15-18years??) it is an all around Sport formula given to me by John McCollum...it works great in all engine sizes....020 to .60 diesel engines. When you run a diesel engine and you use a smaller than normal prop(7x4) you have to increase the compression, combined with a very rich mixture, you'll be running the engine at a very high compression setting which can be a source of the vibes..also it's very harmful to your engine. Also there exists the possibility that the engine is a LEMON. I consider my CS Silver Swallow .15's to be Lemons....there's just too many things wrong with them to bother...cylinder to case fit crooked, loose contrapistons, backplate leaking....You get the idea...I really wish you the best with this engine, let us or me know how it's working out for you. I forgot to ask what diesel experience you have....The Jin Shi is not a good engine for the inexperienced. Tony G

>>No I got the engine from Carlson and did the mods he
>>sugested. I nearly wore my arm out trying to get the thing
>>to start, before I got out the starter. Now it just takes a
>>simple bump of the starter to get it to fire. I'm running a
>>7-4 prop on it and it's running real rich with out the
>>needle valve, so that could be the problem. I have a new
>>needle valve assy from a Fox 35 in it as the holes in the
>>venturi were so far out of alignment I had to ream the out
>>to get a good needle valve assy seating.
>>As for fuel Its Davis diesel 1/2 A mix. I was really
>>wondering if the lack of ether would cause rough running.
>>Cause I got a can of John Deere waiting for the fuel! LOL
>
>Hi Steve, I've been thinking about the Vibe Problem some
>more and after the mods you performed, the engine should
>have smoothed out by quite a bit..I did encounter vibration
>when I went from an 8x4 prop to a cut down
>8x4(7.5"x4")Taipan. the engine was in the 15,000+ rpm range.
>So I kept my props sizes bigger...figuring that the engine
>didn't like to go into that range. I have a Jin Shi on a
>Dumas Tomahawk(330sq") that flys beautifully on 60'X .015"
>lines. It uses a Taipan 9" x 4" prop. another source of
>vibration I've encoutered with some Silver Swallows and all
>my CS 2.49cc diesel engines is a loose fitting contra
>piston. I'm perplexed about your needle valve problem too.
>The Needles on all my Chinese engines run at approx 3.5 to 4
>turns open. another mod I used, as suggested by Ed Carlson
>was to replace the stock venturi insert with a 6.5mm one
>from the Mvvs 2.0cc engine. Ed should still have these in
>stock. I do not know the fuel formula for your Davis 1/2A
>fuel; His fuel works okay I believe. I suggest the following
>formula: 35% Ether-20%Castor-1.5%Amynitrate, and the rest
>Kerosene. Red Max will mix this fuel for you. We have used
>this formula for over a decade(15-18years??) it is an all
>around Sport formula given to me by John McCollum...it works
>great in all engine sizes....020 to .60 diesel engines. When
>you run a diesel engine and you use a smaller than normal
>prop(7x4) you have to increase the compression, combined
>with a very rich mixture, you'll be running the engine at a
>very high compression setting which can be a source of the
>vibes..also it's very harmful to your engine. Also there
>exists the possibility that the engine is a LEMON. I
>consider my CS Silver Swallow .15's to be Lemons....there's
>just too many things wrong with them to bother...cylinder to
>case fit crooked, loose contrapistons, backplate
>leaking....You get the idea...I really wish you the best
>with this engine, let us or me know how it's working out for
>you. I forgot to ask what diesel experience you have....The
>Jin Shi is not a good engine for the inexperienced.
> Tony G

Tony is pretty much correct when he says that the Chinese 15 in any name that you call it is lacking in a lot of areas mainly quality.
I have one that in 3 years of running has never broken in. The cylinder/ piston match is incredably tight and has been lapped twice. The backplates have been sealed, needle valves have been replaced with PAW valves which are very good for these motors. Cranks have been relieved, shafts have been lapped to the case, check this as a lot of them are tight,bushings between driver and case are mandatory as some will not start without a starter.Contra piston fit has not been a major problem in mine yet unless you call excessively tight a problem.
These motors were good for a lot of hours work for very little return for the effort. Yes they are smoother after the work is done but none of them are up to the class of even the old english A.M that they were copied from. Carlson was selling them at 5 for a $100.00 puts them right in the same class as a lot of the junk Russian stuff that you see trying to be dumped on the bay.
The word is that C.S has upgraded their quality since these motors were made. I have one of the newer 15 glow redheads and so far that didn't impress me either.
Buy these if you like to fool with motors for everything else buy a better brand and get your money's worth.

Agree with Preston. A .15 Diesel wants a lot more than a 7-4. Also, a bit more flywheel effect will help on starts.

Experiment with an 8-4, and also try trying trimming a 9-4 to 8.5.

I used at least an 8-4 with my Silver Swallow .15. What I dumbly was put it on a Ring Jr. Too heavy.

Tony G: My Silver Swallow is one of the older ones, and it runs pretty well. Lemon it is not. Currell

>Tony G: My Silver Swallow is one of the older ones, and it
>runs pretty well. Lemon it is not. Currell

Agreed...I'm refering to the CS versions of the SS...the older SS's are nice running, good quality engines..most were made in the late 60's. Some will have the production date under the engine lug..I have 5 of the older version. Tony

Buy these if you like to fool with motors for everything
>else buy a better brand and get your money's worth.

Ron B.
F4Fguy

At $20-$25 each it sounds as if you get exactly what you pay for.

Ron B.

Is this a Yin-Yan?

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Tony, There really is no difference fundamentally between the Yin Yan or the CS or any other variation of the motor that you might have. I've had well over a dozen of them in 20 years. My brother sent me one from overseas in the late 60's and that one wasn't too bad a starter but wasn't very powerful. Quality has varied consideralbly from motor to motor. Remember that this is an old design and was not made on CNC equipment and was really not assembled by skilled labor. So like a lot of early motors there were good and bad. Most of the older modellers here remember a lot of the manufactureres would offer to 'hop-up or factory fit your motor for a small additional charge.Basically they made sure that everything fit the way it was supposed to. It really was the secret of those' factory specials' that a lot of people used in the 50's and 60's
Dennis

MMMMM--Am I missing something here? In all of this discussion I am not hearing anything about WHAT color the exhaust is.I have several 2.5's---for racing I use the APC "pylon" prop 6.5 X 5.5 running in the 21,000 RPM range. The venturi is 7/64 and The needle is bearly 3x4 turn open--have to use 3 drops or choke while proping. NOW, when fuel is pinched down and compression to MATCH the exhaust is AMBER. Not black!!! Oh BTW on that setting it was 8'-13" and 137 laps on one oz of fuel--but not fast enough. OK--SAME ENGINE turning a 9X4 --same thing-- amber exhaust. The engines are broken in. One MVVS took 4 hours to break in--That was exhausting (not amber) I was exhausted!!!!
Yup--hard starting--check ether first thing--been there , done that--Flipped until blue in face.. Oh BTW, diesels have a personality---If you have not run them for a while THEY KNOW IT--and say"Iv'e got an attitude--I don't want to play"!!!! I STILL LOVE EM!! On my R/C (oh, I mentioned R/C) Bi plane 30' span I have a MVVS .09 WITH A 9X4 AND IT FLYS VERY SCALE, Love it!!!

I read somewhere that CS QC was not allowed to reject anything, as it would reflect on the assembler. Sounds about right. I had an Oliver Tiger replica that had so many things wrong with it that I could not get it to run at all, This in contrast to the first one I bought that runs great!

Dave, is the amber (or straw) color only applicable when using castor lube or does synthetic turn the same color? I've only used castor.

Back on the run stand with a new Fox 35 stunt needle valve the engine ran very well. I backed off the compression and adjusted the mixture till the exhaust ran amber. It still requires a quick bump of the starter but fires right off. I have about 30 to 40 minutes on the engine and it is running well now. Need to mix fuel now. Anyone have a favorite home brew?
Thanks for all your help!
Steven Adler

>Back on the run stand with a new Fox 35 stunt needle valve
>the engine ran very well. I backed off the compression and
>adjusted the mixture till the exhaust ran amber. It still
>requires a quick bump of the starter but fires right off. I
>have about 30 to 40 minutes on the engine and it is running
>well now. Need to mix fuel now. Anyone have a favorite home
>brew?
>Thanks for all your help!
>Steven Adler

Hi Steve...please read my prior response #8, for a proven fuel formula. Tony