OS105HZ-R Fuel pouring out of carb?

[Delarado]

Guys,

just been and flown the 700 with a 105HZ-R, and when id finshed a flight and put it in the bench, fuel started pouring out of the carb trumpet, like a constant stream of it!

I unplugged the line from the 1 way to vent the tank pressure and it stopped. plugged it, back started her up for a bit with the fuel line clamped to clear out the fuel, then unclamped the fuel line and she ran and idled fine. Flew her around a bit, cut it off, put it on the bench, no issue.

3 further tanks through it without issue.

Why would it do this? is it a problem?

Cheers!

[dave j]

when you landed did you clamp the fuel line to stop fuel getting to your carb as if you didnt the vacume in the carb with continue to draw fuel up

[Delarado]

No i did not. I thought the pressure regulator on these was supposed to stop that? And why didnt it do it again for the rest of the day?

[dave j]

could have just been a bit of dirt trapped and cleared itself

[Delarado]

fair enough...ill keep an eye on it! just wondered if anyone else has had it. cheers

[Stuart]

The fuel pressurising of the main tank needs to be released.. I have a valve that enables me to let out the pressure in the tank after every flight. Until you release that pressure in the tank as soon as you stop your engine the pressure remaining in the tank will keep on pushing the fuel through the carb the same as a YS engine.

[GIXERMAN]

+1 to Stuart, remaining pressure from tank like the ys

[rachel]

Guys,

just been and flown the 700 with a 105HZ-R, and when id finshed a flight and put it in the bench, fuel started pouring out of the carb trumpet, like a constant stream of it!

I unplugged the line from the 1 way to vent the tank pressure and it stopped. plugged it, back started her up for a bit with the fuel line clamped to clear out the fuel, then unclamped the fuel line and she ran and idled fine. Flew her around a bit, cut it off, put it on the bench, no issue.

3 further tanks through it without issue.

Why would it do this? is it a problem?

Cheers!

I have had this a lot !!!!!!!

the regulator, disk thingy on the main needle gets gummed up with oil on the rear side of the diaphram .

so Here is how to cure it when it happends ,.....

Leave the main needle alone but unscrew its base (8mm spanner on tube thingy) this will remove the regulator (carefull not to loose the sealing washers )

Undo the 1.5 mm cap screws x 5 and remove the cap (there is no orientation)

Remove the clear plastic diaphram (watch its orientation , reinforced side towards the valve)

try to blow through the nipple in to the regulator , if you can its jammed open with dirt , you should only be able to blow through the nipple if you hold the valve open !!!!!!

You can just blow this out or use brake cleaner on the valve DO not strip the valve !!!!!

clean the diaphram with a lint free cloth , as well as the cap you took the 5 capscrews out of .

Reasemble and refit to the engine and go fly :-)

NEVER use brake cleaner to clean the check valve (in the fuel line)

If the regulator sticks in flight the symptoms will be this

The motor will loose power and go REALLY really ritch and will not idle , when you land fuel wil pour out of the carb !!!!!!

If it happends on start up the motor will NOT start and may hydro lock , and fuel will pour from the carb .


I love my HZ-R but this fault is a huge PITA !!!!!!!!

good luck x Rachel

[Delarado]

Fair enough... Im confused though, because it didnt do it the rest of the time! I made a conscious effort to do exactly as I did on previous flights, even flew it and just shut her off and left on the bench while someone else flew their logo - It was sitting a good 6-7 minutes and nothing...whereas before when it happened it was dripping as I picked it up from landing after flight?!

I normally do release the pressure after flying but not right away. I thought the regulators were supposed to stop stuff like this happening? I once filled it up without shutting off the fuel to the carb and it was completely fine... Im just a bit perplexed, if it did it all the time then fair enough, but it doesnt seem to!!

[Delarado]

THanks rachel, that sounds more like what I was thinking. This makes sense to me, because the other day I was flying, autod it in to land, but when I went over the engine had completely stalled (not usual)

I tried starting it again but it was really loading up with fuel. With lack of experience I hydro locked it. Brought it home, pumped tank dry, removed glow plug, turned it over, dried plug off with glow starter, put it all back together and left it till today.

Flew today and on the first flight it happened. So sounds like my regulators gummed up, but maybe it cleared itself in flight?

[rapidgaz]

OS105HZ-R Fuel pouring out of carb?

It depends also on which stroke the piston stopped at, if a certain position the valve remains open for a time, and as others have said about the pressure it need venting. My normal routine is clamp fuel from tank. Then release the pressure straight after the flight and never get a problem.

[rachel]

It depends also on which stroke the piston stopped at, if a certain position the valve remains open for a time, and as others have said about the pressure it need venting. My normal routine is clamp fuel from tank. Then release the pressure straight after the flight and never get a problem.

Good advice, I do this ! but I have still had loads of problems with the reg sticking open :-(

[swale]

Touch wood but never came across this on any of my os Reg email engines that includes a 91hzr

[monsul]

Good advice, I do this ! but I have still had loads of problems with the reg sticking open :-(

Do you guys burn all the fuel in the regulator on the last flight before going home? I always do that (just take out the fuel tube in idle and let the engine die) and never had a problem with my regulated OS91

[Delarado]

I havent been doing that, Ive just been cutting it off using throttle cut