As an aircraft mechanic, to determine the source of a cylinder leak, we apply air pressure to each cylinder through the spark plug port while holding the prop stationary (in your case the flywheel). With pressure on the cylinder we will slowly work the prop back and forth between the end of the compression stroke and the start of the exhaust stroke while listening for airflow through either the air intake, the exhaust, and the crankcase breather. The problem can be immediately elucidated using this method.
It sure does have a good sound to it. Ring replacement sounds intimidating but it goes pretty easy if you need to do it. I really like how smooth and even it runs, I hope he enjoys it too
Hi Samuel, I'm glad that you're enjoying the channel. The R27 looks like a great little engine, I bet it has a sound all its own too. After working on this h74 I am thinking that I "need" one too. Thank you for watching and for commenting 👍
@@samuelhibbard884 have you checked the valve clearance? I'm sure that you added oil to the crankcase and also used mixed fuel when you were ready to fire it up?
@@steam212 yes I used the same stuff you use in your videos. It has oil in the crankcase and 50:1 gas. Good spark. It's not out of time, It had great compression but after it ran for about 3 minutes then it died and lost compression. It has a really different carburetor on it.
Sorry for taking a break from the videos after Christmas, I needed to get the shop back in order and wanted to rearrange some equipment. There are a few videos out before this one. I'm glad that you're enjoying the channel, thank you for watching and commenting 👍
Hello friend. I have an h74 that I stop working it feels like it has compression I’m working on it right now. You think it can be current I changed the batteries I just have to change the piston rings after that if it doesn’t start I’ll be afraid it’s the coil
I have a H75 Engine,after a view times of running he not start again.No Compression! I change the piston o-rings with spare rings 13x1 mm ,same problem! Then i buy o-rings Typ FKM 13,5x1 mm and now he starts per hand,and he has always god compression!
Not very well, I always need to remind myself "scale engine, scale load". I really need to build an adjustable load (prony brake) so we can hear and see what happens. I really wish I could give you a better answer, but you did spark an amazing idea that I'll get to work on.
@@steam212 First of all, happy new year, second, thanks for responding, really appreciate that. Asking, because I am allready since quite some time working on "extreme low speed engines"... Not really interested in how well the governor keeps up, but AM interested in how well the engine deals with increased load at constant (LOW) rpm. Here's an idea of what I am talking about, a single cylinder 5 cc fourstroke driving a variable pitch properller at governed 1500 RPM. The engine is modified to run on gasoline (consumption: 15 ml/hr at max achievable boat speed, which is approx 50% of max achievable engine load) Load test (thumb against flywheel) with electronic governor active: ua-cam.com/video/EeExUNp7Gus/v-deo.html My estimate is that I am seeing 30~40 Watt here. The boat: ua-cam.com/video/20EiBJfWSSo/v-deo.html Right now, I have a Cison OHV fourcylinder coming for a larger project, hoping for 100 Watt @ 1500 RPM
@@mreza84 To be honest with you, the time and effort it would take to make a set of functional cast iron rings and modifying the pistons to accept them is not worth it.
As an aircraft mechanic, to determine the source of a cylinder leak, we apply air pressure to each cylinder through the spark plug port while holding the prop stationary (in your case the flywheel). With pressure on the cylinder we will slowly work the prop back and forth between the end of the compression stroke and the start of the exhaust stroke while listening for airflow through either the air intake, the exhaust, and the crankcase breather. The problem can be immediately elucidated using this method.
As an amateur motorcycle mechanic, I do the same as you have explained.
That thing runs great! Good fix too! I like the common crankshaft sound.
It sure does have a good sound to it. Ring replacement sounds intimidating but it goes pretty easy if you need to do it. I really like how smooth and even it runs, I hope he enjoys it too
So cool! I enjoy watching you tinker on these model engines. I just ordered the r27 engine. But really wanted to see the h74 so thanks 👍
Hi Samuel, I'm glad that you're enjoying the channel. The R27 looks like a great little engine, I bet it has a sound all its own too. After working on this h74 I am thinking that I "need" one too. Thank you for watching and for commenting 👍
@@steam212 well I got the R27 engine and it ran once and had good compression, but then it lost compression. Any suggestions?
@@samuelhibbard884 have you checked the valve clearance? I'm sure that you added oil to the crankcase and also used mixed fuel when you were ready to fire it up?
@@steam212 yes I used the same stuff you use in your videos. It has oil in the crankcase and 50:1 gas. Good spark. It's not out of time, It had great compression but after it ran for about 3 minutes then it died and lost compression. It has a really different carburetor on it.
A great video. Nice engine.
Regards
Steve.
Thank you Steve. I'm glad that you enjoyed watching it. Thank you for your interest and for commenting 👍
That's impressive for sure!
your back YAY
That is a cool motor
@@flynnclement3254 I really enjoyed this one, I may have to look into one for the shop 👍
Sorry for taking a break from the videos after Christmas, I needed to get the shop back in order and wanted to rearrange some equipment. There are a few videos out before this one. I'm glad that you're enjoying the channel, thank you for watching and commenting 👍
Hello friend. I have an h74 that I stop working it feels like it has compression I’m working on it right now. You think it can be current I changed the batteries I just have to change the piston rings after that if it doesn’t start I’ll be afraid it’s the coil
Interesting hobby.
Thank you WRXS, I enjoy it. They don't take up too much space but somehow manage to take up your free time 👍. Thank you for watching and commenting 👍
I have a H75 Engine,after a view times of running he not start again.No Compression!
I change the piston o-rings with spare rings 13x1 mm ,same problem!
Then i buy o-rings Typ FKM 13,5x1 mm and now he starts per hand,and he has always god compression!
Very good tip! Thank you for sharing it with all of us 👍
Good to know.
Wow! How much does that engine cost?
How does it perform under load???
Not very well, I always need to remind myself "scale engine, scale load". I really need to build an adjustable load (prony brake) so we can hear and see what happens. I really wish I could give you a better answer, but you did spark an amazing idea that I'll get to work on.
@@steam212 First of all, happy new year, second, thanks for responding, really appreciate that.
Asking, because I am allready since quite some time working on "extreme low speed engines"...
Not really interested in how well the governor keeps up, but AM interested in how well the engine deals with increased load at constant (LOW) rpm.
Here's an idea of what I am talking about, a single cylinder 5 cc fourstroke driving a variable pitch properller at governed 1500 RPM. The engine is modified to run on gasoline (consumption: 15 ml/hr at max achievable boat speed, which is approx 50% of max achievable engine load)
Load test (thumb against flywheel) with electronic governor active:
ua-cam.com/video/EeExUNp7Gus/v-deo.html
My estimate is that I am seeing 30~40 Watt here.
The boat: ua-cam.com/video/20EiBJfWSSo/v-deo.html
Right now, I have a Cison OHV fourcylinder coming for a larger project, hoping for 100 Watt @ 1500 RPM
Why not use the normal ring? I don't believe this silicon “ring” has a long-life expanse of a real metallic ring.
@@mreza84 To be honest with you, the time and effort it would take to make a set of functional cast iron rings and modifying the pistons to accept them is not worth it.