jkruger

Had an interesting happening running a new YS 175 CDi on a test stand. Using a glow plug instead of the CDi. Engine started easily and ran at low throttle for a couple of minutes then when I advanced throttle the spinner bolt broke. Went back to low throttle with no problems and shut down motor. Prop bolts still tight and no sign of backfire or reverse direction. Suggestions?

Salander

What needle setting did you use? Make sure that you run it rich compared to a cdi setup to take into account the glow plug.

Also, if it was a new APC, they have a habit of needing to be retightened after a while, otherwise it may slip or the spinner back plate may slip.

jkruger

Had the needle valve at 2 1/2 turns. The spinner screw just sheared.
John

XMANS

When you installed the prop etc did you align one blade vertical in line with TDC, if so did you check if the prop blade was still in line with TDC.

If not still aligned you suffered a back fire of some degree, if it was still aligned and all was tight as stated you most likely had a failure of the spinner
bolt. I have seen many bolts suffer from fatigue and break.

As a matter of interest you shouldn't use a spinners alum back plate directly against the drive washer, the splines do not align, a
good alternative is to use a servo disc, the big round one's, and drill out the center to suit your crankshaft and install between back plate and drive
washer, when prop nut is tightened the plastic disc then deforms and takes on the spline shape of each side.
Saves the stripping of the drive washer splines when you have a backfire,
And yes people complain about the spinner gap being too big and then remove it.

YOU CAN LEAD A HORSE TO WATER BUT YOU CAN'T MAKE IT DRINK.

YS SERVICE DOWN UNDER

ThunderBoat42

My Feedback: (1)

GOOD TIP XMANS

kevenoco

My Feedback: (1)

J. Krueger,
I know this is an old posting but did you figure this one out? I'm having the exact same problem. I cannot get to full throttle with a glow plug on the 175 CDI without pre-ignition.

Dave Harmon

It is too lean.....open the needle valve.

speedracerntrixie

My Feedback: (29)

Just curious here, what is the reason for running the engine on a glow plug if it is intended for CDI?

kevenoco

My Feedback: (1)

A lot of people prefer it that way to eliminate the weight and complexity of the CDI equipment. (KISS). I am currently troubleshooting some motor issues so I just wanted to make the diagnosis simpler. I prefer the CDI personally.

I was told that an additional head gasket is required to reduce the compression for use with a glow plug. I never tried it out though.

Dave Harmon

Try back flushing the needle valve assy.
I have had a lot of trouble with silicone chips that are almost invisible caused by Du-Bro fuel line. This line is very soft and very easy to gouge when installed as well as having trash in it before use.
You will have to remove the needle valve brass assy from the carb and back flush the carb housing.
I also flush all fuel line before use....all this has solved most of my problems such as yours.
Of course I use a filter but the silicone chips were already in the carb and fuel line.
I have run my engine a lot on glow and it does not require another head gasket.


Dave

kevenoco

My Feedback: (1)

Thanks Dave. Just to be clear we're talking about the 175 right? I can run a glow plug in my 170 no problem.

Where are you running your HS needle on your 175 with the glow plug? With CDI I am at 5/6 out but with glow plug I am still predetonating even at 2 turns out.

My motor runs great now with CDI but couldn't get it up to full throttle with a glow plug. My fuel passageways are clean.

Bustabloodklaart

Couple observations based on 6 years YS ownership,,,,
The reason most people run initially with a glow is for running in purposes.
All the symptoms above are fuel (ie lack) related. either open the main needle more
and/or check the clunk in the tank.
Xman's tip above with the servo disc is a cracker as is using a cut down sanding disc
or piece of liteply cut into a disc, Either that or welcome to the world of YS propdriver
replacement
Doubtless some of the guys here will read the following and think "I've never" etc etc
but again based on years and lots of use, get used to tightening your prop nuts at
least every 30 or so runs as a precaution.
PS
If you can always splash out a few pennies more and buy YS fuel tube.

jkruger

After a couple of years because of a move, got back to my 175 cdi. Opened the needle to 3 full turns and it ran fine until the black check valve came off the head. How exactly is that part attached to the engine?
John

kevenoco

My Feedback: (1)

I think it's originally press fit only. YS has told me to sand up the surfaces and apply a very light coat of JB Weld and hammer it back in. This has worked on my 170. Use a nut driver on the plastic injector and hammer on that.

petec

My Feedback: (58)

If the injector came out cleanly from the head, meaning that whole brass body came out and the aluminum of the head is intact, then you can clean the whole thing with denatured alcohol to remove fuel residue. Once that is done use a small jewelers file to rough up the opening in the head and the brass of the injector. The end result you are looking for is not to remove material as much as provide a reply good rough surface, almost like very light threads, for the JB weld to bite into. Then mix up some JB Weld and apply a thin coat to the injector. Once that is done press the injector back into the head.

Now if the injector is broken that is a different story and will require a trip to Richard for repair and maybe a new head.

Does that help?

jkruger

The brass piece broke and after talking to Richard I will send the engine to him for repair. Thanks

spaceworm

Please excuse my ignorance, but who is "Richard"? I don't need him (yet), but would be good to know about him. Thanks.

Sincerely, Another Richard

YS F-120/Hangar 9 100 inch J3 Cub

tande

My Feedback: (48)

Last I knew, he called this place home away from home.......

petec

My Feedback: (58)

Richard Verano is the owner of YS Parts and Service. He is the North America YS distributor and all around YS guru.