Trouble starting new Hobao Hyper SS with Hyper 30 Engine

[Shaundpee]

HI Guys. My name is Shaun. I'm a newbie in this forum and to nitro rc. I'm having an issue with my Hobao hyper ss cage truggy with the Hyper 30 engine that is brand new. For some reason, getting it started is a hassle and not working out. I have the car for three days now, I will give a break down of each day what really happened.

Day1:
In an attempt to start the engine to break it in, the pull starter snapped! Eager to start the car, I used a home drill onto the backplate hex to crank the engine. However doing this led the one way bearing breaking . Called it a day as it was not possible to start anymore.

Day 2:
Managed to get a starter box. The engine started immediately! Used to cut out after 10 seconds or so, so I richened the the lsn slightly until perfect. Idle gap was set to 1mm opening and hsn to factory break in settings. The car idled excellent throughout the entire tank fuel. No hiccups, no wanting to switch off etc. Attempted to start the car when tank was done, but starter box battery was dying so was not able to start it. However the flywheel was feeling way more harder to turn now after letting the engine idle for a tank fuel.

Day 3:
Charged up batteries for glow igniter and starter box. Primed engine and attempted to start. The flywheel was so tight it was impossible for the starter box to turn it. I loosened the glow plug a bit and was able to start the car and then tightened it once the idle settled. The car idled perfect for 20 minutes or so, afterwards I could hear a few hiccups, and the rev was picking up slightly and dropping as if it wants to stall. Eventually the rev picked up very high for a few seconds and engine died. I attempted to start again but had to loosed glow plug. The car started, and after 2 seconds the rev will shoot high a lot and wheels will spin. Tried adjusting lsn to slighting richer but was not helping. Same occurred. The effects were very similar as when you pinch the fuel line and the car would rev up and die.

Eventually the car stopped starting. I confirmed that the glow plug is working. What I noticed was when I blew in the pressure line to prime the engine and get fuel in the carb, the engine would want to start but sounds like not getting additional fuel to continue. Once that fuel burns up in the carb, the car just wouldn't even attempt to start. I then removed the fuel line going into the carb, blocked the stinger pipe to see if fuel was going into the card. I noticed that very little fuel was coming out the fuel line and does not look normal in my opinion. The fuel was just barely coming out the pipe. So my thoughts were there is no fuel going into the carb now. A lot of fuel comes out when I blow through the pressure pipe from the exhaust so I know that's fine.

Could it be that by loosening the glow plug the engine does not have enough compression to draw in fuel? But this started while the car was idling with the plug in tight. Or could there be leaks somewhere causing compression loss?

I would really appreciate any help from you guys to diagnose this!

 

[monstertruckier15]

first when starting a new engine add a few drops of after run oil and spin the engine over without the plug in.
Second use a fuel filter if one was not with kit.
third when starting a new engine loosen the plug 1/4 turn to make starting easier
four prime the engine by blocking the stinger to push fuel to carb.
five once engine starts leave glow plug ignitor on to warm engine up and slight tighten plug. Engine will warm up after a minute or two.
six remove ignitor and tighten plug and let run. let engine run a few minute and shut off and cool down and repeat a couple times . each time run a little longer. 2-3 times and then you can drive the buggy and put some load on it. continue to break in engine.

I don't like pull starter as you now know what happens. I replace them with a Sullivan tiger drive.
I don't use bump boxes as the are expensive. I just use a HD starter and rubber wheel for my 1/8.

Overall I suspect that crap has got in the carb blocking the fuel flow. Possible seizing the front bearing? I would remove the clutch and flywheel and see what's going on and try and spin the motor over. to. Check the carb by opening it wide open and priming the engine to see if there is a stream of fuel?
Reset the carb low back to factory setting and see if you can see the stream of fuel. You may have to clean out the blockage in the carb needles. If that is the problem then you better add a fuel filter. The problem came from how you put fuel into the tank. This usually if from buying quarts of fuel and you poor it directly into tank without some type of filter screen. Contaminates float in the air and go right into the tank with out seeing . I use a fuel pump with 2 filter screens an buy my fuel buy the gallon.

The loss of pressure cold be a block pressure nipple fitting on the exhaust pipe.

You having some success but impatience set in. There is a lot to learn with nitro. once you get it it's easy and preventable.

 

[alfredwong2003]

It is possible that your exhaust header is loose a bit or there is a leak there.

 

[Shaundpee]

Thanks for the response guys! Will definitely try starting it how you mentioned @monstertruckier15. Is it possible to use WD40 instead of after run oil? Will have a look at the carb and flywheel as well.
@alfredwong2003 I removed the exchaust manifold last night and re attached it making sure it is sealed good.
I will try today and give feedback. Thanks guys.

 

[Shaundpee]

So I've had a try starting it today with no luck. When I add a bit fuel into the glow plug hole and try, it starts for like a second. So my thought was there is no fuel going into the cylinder?

I removed the air filter with the throttle wide open and blew through the exhaust pipe and can confirm a lot of fuel going into the carb. So there is no blockages in the carb and no air leaks in the fuel tanks and lines. I then attached the exhaust pressure line back, blocked the stinger and cranked the engine. I can tell that very little to no fuel enters the carb. I am not sure if this is good or should more enter? I removed the fuel line going into the carb and cranked the engine with the stinger blocked. Very little fuel leaves the pipe with hardly any pressure.

To test if fuel is actually entering the cylinder from the carb, I removed the glow plug and cranked the engine to see if fuel spills out. When I blow into the fuel line and more or less flood the carb, then crank the engine, the fuel spits out the glow plug hole. But when I re-attatch the line back to the exhaust and block the stinger to prime the engine, no fuel spits out the glow plug hole. Even if I do this for a long time. I've attached a google drive link of videos I took. The first video is when I blow through the hole and you can see a lot of fuel comes out. Also into the carb a lot goes in. The third video when I prime the engine by blocking the stinger, you can see hardly any fuel comes out the line.

So my thoughts are there is not enough pressure building in the exhaust to push out the fuel? Or a leak somewhere? I checked the manifold rubber. It seems fine but I feel it is a bit loose. I've attached a video of it as well.

Any thoughts guys?

Also there is a fuel filter attached.

https://drive.google.com/drive/folders/1gr9PehQ9cFKxi8sd04Dl70ENKMym3PwZ?usp=sharing

Please let me know if the link works

 

[monstertruckier15]

wd40 is bad. check the pressure fitting on exhaust too.

 

[Shaundpee]

that’s the nipple on the exhaust that leads to the fuel tank? What exactly will I be checking for and how to check it?

 

[TheOneTrueMorty]

It's the line between exhaust and fuel tank. You can check this by pluging the exhaust and launch the engine without igniter, fuel should get to the carb.
I got similar problems with a nitro engine and it turned out that the factory settings for the carb were not suited to my location, as the best settings depend on air pressure, humidity and temp. Check this guide it should help

 

[Shaundpee]

Thanks! Will definitely have a look.
I did block the stinger to prime it, but very little fuel it manages to push out. I feel that fuel is too less. It like just makes it to push out some fuel.

 

[monstertruckier15]

that’s the nipple on the exhaust that leads to the fuel tank? What exactly will I be checking for and how to check it?

If it's blocked it won't pressurize the tank pushing the fuel to the carb. Stick a small pin or drill threw to make sure it's not blocked. Then block the manifold end and blow threw the line. Air should come out the stinger end.

 

[monstertruckier15]

It's the line between exhaust and fuel tank. You can check this by pluging the exhaust and launch the engine without igniter, fuel should get to the carb.
I got similar problems with a nitro engine and it turned out that the factory settings for the carb were not suited to my location, as the best settings depend on air pressure, humidity and temp. Check this guide it should help

I have never had a issue with any nitro engine that wouldn't start and run using the factory settings. The factory setting are set rich. The low was you problem. It's never the high and the fuel always contributes. Don't use car blend fuel! I could never get a Os engine to run on car fuel. Why? The oil lube content was too low. Os recommends 18% oil lube less cause problems. The fuel I used had 12% and I was always running 18%.

 

[alfredwong2003]

Today engines are very delicate, I guess it is the trade off between power and easy starting. In the old days we never have to connect the exhaust to the fuel tank and engine can still start right up. The fuel will get suck into the engine with ease. I guess the bigger throttle opening allows more air get in but reduce the fuel sucking capability.

 

[tntpoof]

wd 40 is not a after run oil..wd 40 is a water displacer .it then leaves a film over anything it touches..a micro lube is also a very good way to treat any metal part..Zmax love the slight purple..

 

[Shaundpee]

Ok so good news, I removed the engine and sealed the backplate with gasket sealant. The fuel has much more pressure into the carb and the car started. I just think the card settings are off. Power is cutting out on full throttle and like a burbling choking sound. Also when I remove the glow plug igniter the engine dies off. i Think it’s running too rich?

 

[monstertruckier15]

Turn up the idle. The engine should run with the factory settings. Try a new plug.

 

[Shaundpee]

Finally got the engine running good. I think i had the hsn set a bit too rich. Plus I changed the plug. Managed to drive a full tank with no issues. Just need to break in a few more tanks and will start tuning the hsn and lsn.

Thanks for the help!

 

[stevendavis]

pre-heating the engine will help with starts and longevity!

 

[monstertruckier15]

what ever you do only adjust the low first then the high no more than 1/8 low. and 1/8 turn on high max 1/2 turn from factory start.

 

[arobo96]

Did you ever get it tuned well and to be able to hold a tune. I found damaged seals in the carb of mine so waiting on a repair kit under warranty cheers