RunRyder RC
 1  Topic Subscribe
WATCH
 1 page 607 views
Scorpion Power Scorpion Power
HelicopterEngines Plugs Mufflers Fuel › First start of os .91
12-05-2011 03:11 AM  5 years agoPost 1
CF1

rrApprentice

Olympia, WA

My Posts: All  Forum  Topic

I have a new .91 that I will be firing up for the first time in a few weeks. My question is I have seen some people talking about shimming the head until it is broken in. Is this something I need to do? If so where do I get the shims and how do I do it?

PM  EMAIL  GALLERY  Attn:RR  Quote
12-05-2011 08:09 AM  5 years agoPost 2
poerQwa

rrVeteran

Rotterdam, The​Netherlands

My Posts: All  Forum  Topic

Hi,

Whether to use a shim(or is to shim ) or not depends on quite a few factors. I know of 2 reasons to place a shim.
1. Change the timing of the detonation to allow for smoother running of the engine;
2. Lower the compression somewhat to allow easier starting of the beast.

Point 1 really is part of "advanced tuning" and needs to take climate, plugtype, fuel into account (only to mention a few). In my book it is point 2 why you might want to shim.
Also make sure you have a hi-torq starter like the sullivan on at least 18 or higher volt.

Goodluck.

Marc

PM  EMAIL  GALLERY  Attn:RR  Quote
12-05-2011 02:22 PM  5 years agoPost 3
CF1

rrApprentice

Olympia, WA

My Posts: All  Forum  Topic

Your second point is what I had read of people doing. Would you say it is recommended to lower the compression during break to do this?

I did get a shim with my motor but it had slid under the motor and got a few dings in it. I'll look and se if I can order a replacement.

Thanks,
Chris

PM  EMAIL  GALLERY  Attn:RR  Quote
12-05-2011 02:42 PM  5 years agoPost 4
koppter

rrApprentice

Virginia

My Posts: All  Forum  Topic

nitro

Chris, engines need to be broken in in the environment and conditions that they will be operated in. model engines are very simple 2c engines - same as chain saws, and weed whackers. there is no reason to use a shim during break in, and as long as you have fuel and a working glow plug, there are no tricks to starting. read and follow the mfrs instructions on the default settings. once in the air, fly around, but avoid hard stresses on the engine until you have about a gallon through it.

nor do you need an 18v starter...12v will work fine.

i have 2 Align/OS .91s.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-05-2011 06:14 PM  5 years agoPost 5
poerQwa

rrVeteran

Rotterdam, The​Netherlands

My Posts: All  Forum  Topic

nor do you need an 18v starter...12v will work fine.
good to hear you do not have any problems.
Things were different in my case and my 16.8v(thought it was 18) starter setup helped quite a bit of colleague flyers at the field too.
Not sure if the "pumped" OS I owned was just harder to start than the 91S

@CF1
I would also suggest to use the engine as is. If cranking it up does not work for you you might use the shim and see if this alleviates the problem

PM  EMAIL  GALLERY  Attn:RR  Quote
12-05-2011 06:22 PM  5 years agoPost 6
CF1

rrApprentice

Olympia, WA

My Posts: All  Forum  Topic

That sounds like a good plan. I'll see how it goes on first start. I ordered a new shim so I have one on hand as the one that came in the box was dinged up.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 607 views
Scorpion Power Scorpion Power
HelicopterEngines Plugs Mufflers Fuel › First start of os .91
 Print TOPIC  Make Suggestion 

 1  Topic Subscribe

Friday, November 24 - 8:41 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online