OS105 HZR runs super rich (problem solved)

[Mikey D]

My 105HZR runs super rich! High end needle is almost closed yet is still super rich.


This week at IRCHA I stopped by the Futaba tent and described my problem to Steve Kaluf. Steve provided me with a new high end needle valve holder. He mentioned the holes for the fuel inlets were drilled out to big and this was just recently discovered.

Well sure enough after the simple swap out with the old one the motor came to life! VERY VERY pleased with the motor now!

Leaving this message because I had seen some postings with similar problems, but with no real remedy.

Mike

[Don S]

How about the mid needle holder? Got part numbers?

[dchekas]

The mid needle holder is correct, it doesn't need any alteration.

The main needle seat is where an adjustment has been made. The center hole that the needle rides in has been reduced.

[Flat Eric]

Anyone know the best way to contact os in the UK? I need a few of them

[sdunne]

Originally Posted by Flat Eric

Anyone know the best way to contact os in the UK? I need a few of them

Maybe try contacting "Just Engines", if he cant help I'm sure he will know who can.

[Rob43]

Originally Posted by Mikey D

My 105HZR runs super rich! High end needle is almost closed yet is still super rich.


This week at IRCHA I stopped by the Futaba tent and described my problem to Steve Kaluf. Steve provided me with a new high end needle valve holder. He mentioned the holes for the fuel inlets were drilled out to big and this was just recently discovered.

Well sure enough after the simple swap out with the old one the motor came to life! VERY VERY pleased with the motor now!

Leaving this message because I had seen some postings with similar problems, but with no real remedy.

Mike

Nothing like a simply resolution like that! If only a fraction of the engine tuning issues were that easily remedied. Of course, I bet you had some frustrating times getting there after spending for the big power and all.

[Mikey D]

Originally Posted by Rob43

Nothing like a simply resolution like that! If only a fraction of the engine tuning issues were that easily remedied. Of course, I bet you had some frustrating times getting there after spending for the big power and all.

Sucked a lot fuel, that was frustrating, but mostly just puzzled. I'm glad I went to IRCHA!

Mike

[wichitafc98]

Dhh
Taxi
Mea

[CyprusFlyer]

That is typical, spent weeks on this and the only solution was to fit the standard HZ main valve seat but the settings were way out from the manual! I went through gallons of fuel, bought a spare regulator and finaly purchased a HZ carb and standard crankcase cover, must say since then my engine has behaved perfectly but it has been an expensive adventure, OS thanks for nothing!

PS, its the same for the 55 HZR, changed that over too.
And is the new valve seat the same as the HZ part now, or is the hole size between the HZ and wrong old part?

[Sirolf]

Yes... really typical.
What i would like to know if this new main valve seat does the needle when fully seated
close completely?

[Don S]

I just hope the part I ordered is not old stock. I'll have to do a comparison when it gets in.

[Sirolf]

Originally Posted by Don S

I just hope the part I ordered is not old stock. I'll have to do a comparison when it gets in.

Do you have a part number?

[Don S]

O.S. Needle Valve Holder 61ER 29088940

[Sirolf]

Originally Posted by Don S

O.S. Needle Valve Holder 61ER 29088940

Appearantly this is the number for the stock one which is incorrect.

[Rodney Kirstine]

Originally Posted by Sirolf

Appearantly this is the number for the stock one which is incorrect.

They didn't change the part number, just revised the part. It makes it pretty hard to know if you're getting the new version, or not.

[Don S]

If I see a difference, I'll post some pics. Should have it by the end of the week.

[Chris Wall]

You know, it certainly would be nice if they were to answer email or post a FAQ on the website on how to acquire the new component! I mean they are making us all risk destroying a good motor over a $11.00 part! I guess I'll try calling them tomorrow - "Telephone: 1-217-398-8970. Available Monday-Friday, 8am-5pm U.S. Central Time."

[dchekas]

The old needle seat will not destroy the engine. Quite the opposite, the issue is some engines can't be leaned enough to make maximum power.

In some climates/areas, the engine tunes just fine with the existing seat. If you're able to get satisfactory power out of the engine, I wouldn't really sweat the new needle seat.

I spoke with Steve Helms at IRCHA regarding this. I believe he stated that tower was 2-3 weeks out on receiving any new needle seats. Current stock would be the "old" seats.

[Chris Wall]

Originally Posted by dchekas

The old needle seat will not destroy the engine. Quite the opposite, the issue is some engines can't be leaned enough to make maximum power.

In some climates/areas, the engine tunes just fine with the existing seat. If you're able to get satisfactory power out of the engine, I wouldn't really sweat the new needle seat.

I spoke with Steve Helms at IRCHA regarding this. I believe he stated that tower was 2-3 weeks out on receiving any new needle seats. Current stock would be the "old" seats.

My understanding from other forums was that this also solved the rich-lean-rich running of the motor...

They found that the seat had been miss machined and causes a problem with the suction on the regulator.

[Don S]

Originally Posted by dchekas

I spoke with Steve Helms at IRCHA regarding this. I believe he stated that tower was 2-3 weeks out on receiving any new needle seats. Current stock would be the "old" seats.

Bummer. Would be nice if folks would answer PM's before I buy identical parts that won't change a thing (nobody in this thread BTW).

I need to get on my gasser project.