Need help with GX160 clone

[Texan4Life]

Originally Posted By: edhackett
Are the cam gears right?! Those look like two different gear patterns to me.

Ed


yeah they match. Looking back at the pic it does seem odd. But thats because the crankcase cover supports that end of the crank and cam. If I were to hold it straight like it would be when the cover is on, the mesh looks normal.

 

[lars11]

You were careful not to grind off the machining marks on the head gasket mating surfaces, making it too flat, right? That may cause gasket blow out. Just thought the cleaned surface looked really shiny on the pic...
This is a great forum post, by the way! This engine is better cared for now than the helicopter stuff in the air force.

 

[Texan4Life]

Originally Posted By: lars11
You were careful not to grind off the machining marks on the head gasket mating surfaces, making it too flat, right?


yep I clean gasket surfaces by hand and I take my sweet time. I couldn't find my gasket scraper (just a razor blade with a handle) So I used my pocket knife and then shined it up with a piece of scotch-brite pad.

Almost done:

...BANZIGA!

Just got done with the test run on the back porch.... It runs like a champ again!!

My official verdict was a sticky valve.

 

[boraticus]

"My official verdict was a sticky valve."

Probably caused by excessive amounts of two cycle oil added to the fuel.

I've burned two cycle oil my old Tecumseh 3.5 h.p. lawnmower on occasion when I'm too lazy to haul the machine back to the fuel shack for proper fuel. Never had any issues. However, I'd suspect that a steady diet of TCW-3 in a relatively close tolerance engine will lead to problems.

Very informative post by the way. Thank you.

 

[dakota99]

Now im curious, would using mmo regularly in my gas cause a buildup like this? I know two cycle oil and mmo are probably different, but im curious.

Rate is 1 oz mmo in 2 gallons of gas.

 

[Hootbro]

Originally Posted By: dakota99
Now im curious, would using mmo regularly in my gas cause a buildup like this? I know two cycle oil and mmo are probably different, but im curious.

Rate is 1 oz mmo in 2 gallons of gas.


MMO will not build up like this. MMO has been used for decades on small engines by many people as a fuel stabilizer.

 

[Jim 5]

Interesting.


An engine that only runs on choke among other things can indicate a significant lean condition off choke.

Too much 2 stroke oil will make an engine run lean because there is less fuel in the liquid going through the carb. Obviously you had a valve issue, but the 2 stroke oil in addition to messing with your engine internals could also have been a minor contributor to the problems you were having.

I live at 4,000 feet above sea level and I run a 32:1 rather than a 50:1 mix in my 2 stroke equipment. Partially due to longevity, but also with the knowledge that my mixture needs to be leaner at this altitude than at sea level.

 

[wsar10]

yeah I know this is an a month old thread but I did not want to start a new one for just a question,

I got my kids a Baja mini-bike two years ago and its the GX160 clone, as it stands now i have 10-30 ML syn blnd in it my question is what should I have in it ?
somebody told me to use 30w from now on that is non-detergant ???

It would be nice if I could use the same in the push-mower, lawn tractor and mini-bike !!

 

[Nick R]

Great thread this one. That chonda actually looks pretty high quality inside too. My bet is if they used good carburetors, they would be great machines. Also, as far as the Nylon cam gears in Briggs go, those are plenty durable to last a long, long time. Nothing to worry about, though metal would be nice.

 

[SOHCman]

Originally Posted By: dakota99
Now im curious, would using mmo regularly in my gas cause a buildup like this? I know two cycle oil and mmo are probably different, but im curious.

Rate is 1 oz mmo in 2 gallons of gas.


The recommended dosage of MMO is 4 oz per 10 gallons, so you may be running it a bit thick but probably no worse for wear. MMO is more of a cleaner/UCL, whereas two cycle oil is just a UCL in 4 stroke applications.

As to what oil to run in a chonda on a mini bike, I would think the Maxlife would work just fine, and Rotella T5 would be another robust choice.

 

[wsar10]

Originally Posted By: SOHCman
Originally Posted By: dakota99
Now im curious, would using mmo regularly in my gas cause a buildup like this? I know two cycle oil and mmo are probably different, but im curious.

Rate is 1 oz mmo in 2 gallons of gas.


The recommended dosage of MMO is 4 oz per 10 gallons, so you may be running it a bit thick but probably no worse for wear. MMO is more of a cleaner/UCL, whereas two cycle oil is just a UCL in 4 stroke applications.

As to what oil to run in a chonda on a mini bike, I would think the Maxlife would work just fine, and Rotella T5 would be another robust choice.


thats what I like to hear,becuase I am getting ready to switch my 4.0 jeep to T5.

 

[Roger1960]

Out of curiosity, I checked with the Harbor Freight parts department (An 800 number in India) They sell two models of this generator, an EPA model and a CARB certified model. (For us in sunny Calif.)

They show no availability for the CA model, but for the EPA 49 state model you can get a new carb for $9.00.

I have a sneaking suspicion that the EPA model carb would probably fit on the CA model.

Of course they advise that the carb is not a stocked part, so it would be a special order from the factory taking 6 to 8 weeks. Good news is that you only pay the postage from HF's warehouse.

Since you are obviously pretty good at spinning a wrench, you might want to order up some spare parts like carbs, ignition coils, and what ever parts you suspect might go on the fritz sometime. 2 months is a long time to wait for a part for an emergency generator IMO.

Another bit of checking and I come up with an OEM Honda carb for $66.95 and a Rotary aftermarket for $28.95. Seems to me if the HF markup on ChiCom carb for $9.00 is a whole lot less than other places.

I wonder if you could adapt a Briggs or Tecumseh motor to run with a Chi Com carb that had adjustment screws for the mixture and speed...