H50 rings

[mulch]

My blower started running very ruff. It was actuallly puttering and spitting oil out of the muffler. Pulled the head and no obvious damage but pools of oil in the CC. Pulled the piston and measured ring gap. Top comp about .04+, 2nd comp about .04, oil the same Time for new rings

Where should I get these? Jacks has some after market. Amazon has some Oregon?????

Tecumseh H50 65077 rings 34854

[HondaG100]

I can't really help you decide where to buy rings but I do think you should investigate further than just rings. Pools of oil in the combustion chamber of a running engine are very unusual. You have a plugged crankcase breather or similar issue somewhere causing positive pressure which depending on how this engine is set up will send oil into the carb/air filter.

[bgsengine]

I can't really help you decide where to buy rings but I do think you should investigate further than just rings. Pools of oil in the combustion chamber of a running engine are very unusual. You have a plugged crankcase breather or similar issue somewhere causing positive pressure which depending on how this engine is set up will send oil into the carb/air filter.

Well, with a .040 ring end gap , I would imagine combustion blow by would do the trick, no? - However, depending on the engine, it more likely has a direct vent breather I would suspect - couldn't tell without model and spec to see what pieces it is supposed to have originally.

and to Mulch: were I to get aftermarket - what I have found that they are all pretty much coming from the same source.. in fact most of them I have found, have the same exact packaging inside - take 'em out of the box, couldn't tell the difference... so I'd tend to just go with best price I can find..

But as correct as HundaG100 may be - it is a little too late - but once you have 'er back together you will want to make sure you verify it is not dumping oil out the breather tube into air filter housing (if it has breather tube - if it is a direct vent, then pretty much rings are all it might be)

[KE4AVB]

Tecumseh H50-65077? (Missing suffix letter)

Something else to before ordering rings is the current cylinder condition. If the cylinder bore is worn more than .005" (.127 mm) oversize, out of round, tapered, or scored, it should be re-sized to .010 or .020 oversize (.254 mm or .508 mm). In some cases engines are built with oversize cylinders. If the cylinder is oversize, the oversize value will be imprinted in the top of the cylinder.

Also just putting in a new set of rings in a worn bore will have sealing problems unless the cylinder is deglazed and trued. Using a flex hone will only make things worse if out of round or tapered. In this case a rigid hone need to be used. Using the old rings can also be problematic as they are worn to the current cylinder shape and if the cylinder is out of round then they would not seal properly either due the re-positioning.

The H50 standard bore was 2.625-2.626" [66.675-66.700mm]

Also check out Tulsa Engine Engine for the parts if going with aftermarket as they usually got some fairly good prices.

[mulch]

You have a plugged crankcase breather or similar issue somewhere causing positive pressure which depending on how this engine is set up will send oil into the carb/air filter.

I originally thought that this so I inspected. The engine is direct vent and I looked at the tube and the port in the case but 0 blockage and the breather seems fine (open and closed with mouth pressure). Did I miss something?

Tecumseh H50-65077? (Missing suffix letter)

Something else to before ordering rings is the current cylinder condition. If the cylinder bore is worn more than .005" (.127 mm) oversize, out of round, tapered, or scored, it should be re-sized to .010 or .020 oversize (.254 mm or .508 mm). In some cases engines are built with oversize cylinders. If the cylinder is oversize, the oversize value will be imprinted in the top of the cylinder.

Also just putting in a new set of rings in a worn bore will have sealing problems unless the cylinder is deglazed and trued. Using a flex hone will only make things worse if out of round or tapered. In this case a rigid hone need to be used. Using the old rings can also be problematic as they are worn to the current cylinder shape and if the cylinder is out of round then they would not seal properly either due the re-positioning.

The H50 standard bore was 2.625-2.626" [66.675-66.700mm]

Also check out Tulsa Engine Engine for the parts if going with aftermarket as they usually got some fairly good prices.

I did inspect the cylinder and now obvious damage. I do not have a measuring instrument to check bore other than a dial caliper so deeper than an inch is not possible. At that depth all looks good. I did hone with a rigid hone and didnt look too bad when done.

Now that im in there and with the rings so far gone that is where I will start. If still blow-by what to test on the breather??

[KE4AVB]

Personally I can't see the difference between a in spec cylinder and one that is out of spec.

You can use a set manual calipers along with your dial calipers. Available at Harbor Freight. They have spring load telescopic gauges but I don't like their accuracy. It takes a little time to get the feel of these but they work very well with my 6" digital caliper. The second one from the left is the inside measuring one.

If you are still having excessive blow by then rings are not sealing. As for breather it is only a check valve. If it is as you described then it is working. To check for excessive blow by you need a leak down tester.

[HondaG100]

I originally thought that this so I inspected. The engine is direct vent and I looked at the tube and the port in the case but 0 blockage and the breather seems fine (open and closed with mouth pressure). Did I miss something?

Sounds like you got it covered. Let us know if new rings get it sealed up.

[mulch]

A shot in the dark here but thought Id try. I have a set of new rings Tecumseh # 36076. I couldn't find a cross reference to mine, Tecumseh # 34854, but are these interchangeable. Yes I know these are old Tecumseh #'s and there are alternatives for these but based of of OE #'s will they work?

[KE4AVB]

Research indicates no.

The 36076 (40006) were for the HS50 which had a larger cylinder bore; actually they had different standard bores (2.795 or 2.812 depending version) and both are larger than the H50's standard bored of 2.625" which used the 34854 which is NLA but Stens still makes an AM version (500-355).

[mulch]

Im just about to order the rings but I just cant get my head around this issue. I did test compression before I pulled the rings and it was at 60psi. I know that that is not great but I have seen much worse and with no blowby issues. I agree that this usually points to breather/pressure issues but that is one of the first things I checked.

Just to clarify the issue:
Pull to start and it fires 2nd pull
Starts to sputter and will die unless I feather the choke ( open and close).
Spits oil out of the muffler during this rough start.
After a few minutes of this it just takes off and runs at full throttle and I can use.
During use I smell a VERY rich running engine.
If I stop the engine and pull the plug I can see that the CC is wet (oil) and the plug is fouled.
If I then try to start the issue continues.

I did check oil level many timnes and even drained some and attempted without any difference.

Either way I am ordering rings I just want to make sure that there not some other direction I need to take. Once i get the rings I will find out.