Robin Subaru engine unrealistic maintenance?

[Charlie Abel]

While doing research on which bike engine to buy, I read the service manual for the Robin Subaru Eho 23 to and 35 4 stroke engines. It says every 200 hours to "ocverhaul" the engine: replace piston rings and other components.

This seems unrealistic to me.

Comments?

 

[zean]

Hi. Maybe it's to be in compliance with exhaust emissions, and it says: "every 200 hours if necesary".

 

[Charlie Abel]

It doesn't say anything about emissions, but every 200 hours is unrealistic, and the only way to see if the piston rings need replacing is to take the engine apart and measure them, which most people aren't going to do themselves, and it's too expensive for a shop to do it every 200 hours - I won't be buying this engine

 

[Pilotgeek]

"...which most people aren't going to do themselves..." I'm not sure about that. A lot of people on this forum are quite willing to tear apart their engines.

200 hours is quite a long time. In the two years I've had my two stroke, I have around 80 hours on it, and I've already rebuilt the thing! If you're going to build your own motorbike, you have to have a decent level of mechanical knowledge. Rebuilding a small engine is not too difficult. Even then, I'm sure 200 hours is a low estimate. Many places recommend you change your car's engine oil every 3000 miles, but most modern cars with modern oils can easily go 8k-10k on an oil change. So no, it doesn't sound unrealistic to me, it sounds like a manufacturer recommended safe number.

 

[zean]

Hi Charlie Able. My manual says printed in Japan, February 2004. I've read more than once the Robin Subaru manufacturing facility in Japan is a first class operation with excellent quality control.

 

[Ibedayank]

at 30mph that is 6000 miles of distance traveled

Why would I pay somebody to do job that I can do in 2 hours or less on a sunday after noon. Good luck finding a small motor that needs nothing to stay running in top form. remember these motors are just motors used on weedeaters not #200+ pound motors found in a car

 

[2door]

200 hours? Let us know how many miles you ride in 200 hours. Realistically? It doesn't sound so unreasonable to me. But, like has been said, it's a factory recommendation, not carved in stone or a law. You'll know if/when the performance begins to degrade. Schedule your top end rebuild on that, not what you read in a book or an Internet website. 200 hours is a heck of a lot of bike riding my friend.

Tom

 

[The_Aleman]

The Japanese are pretty conservative when it comes to engine replacing. In Japan, they tend to replace automotive engines before they make it to 100K miles.
These engines are often resold outside Japan for high performance use, advertised as "JDM" engines.

This early engine replacement is kind of ironic considering their high mileage reputation in the US.

 

[Charlie Abel]

My point is that a 2 stroke is not going to need near that amount of maintenance. I have about 300 hours on my weedeater in 1 1/2 years and I don't need to replace piston rings, and I know people that have 15-20 year old weedeaters that are still running with no piston ring replacement and no need to disassemble the engine block. I take a 2 stroke and pass on the 4 stroke myself.

 

[Goat Herder]

I peaked into both of my Morini engines, that I have run both of them at 6000 miles. The bores still had there cross hatch distinguishably present. The piston skirts did not have any scuff marks ether. They had the factory machine marks unblemished and very distinguished as well. Not one scuff mark..

 

[Pilotgeek]

My point is that a 2 stroke is not going to need near that amount of maintenance. I have about 300 hours on my weedeater in 1 1/2 years and I don't need to replace piston rings, and I know people that have 15-20 year old weedeaters that are still running with no piston ring replacement and no need to disassemble the engine block. I take a 2 stroke and pass on the 4 stroke myself.

If anything, a 4stroke is going to last a lot longer than a 2stroke engine. 200 hours is worst case scenario. Who reads the manufacturer recommendations, anyway =P

 

[Ibedayank]

you don't like the motor then don't buy it.... that simple

 

[Greybeard]

I was looking @ Honda and Yamaha Gen sets and noted that Yamaha had more hours as
"emission compliant" than the Honda. I'm sure this is just a dodge to settle the feathers on our epa nannies. Recomend a stringent maintainance program that nobody follows, so you can sell these suckers in all 50 States.

 

[happyvalley]

I have 500 hours on one Robin EHO35 recorded on a tach/hour meter over the past 5 seasons. The only maintenance I've done is frequently change the oil and wash the air filter. I check valve lash once a year. Twice, maybe three times, I've given it a Seafoam treatment misting through the carb to clear out any carbon build-up in the upper cylinder and off the piston crown. I always run good, fresh gas. That's it, never torn the engine apart. Still runs great.

As they say, YMMV, lol.

 

[Charlie Abel]

Re: 4 strokes last longer than 2 strokes? That's debatable

I used to think that 4 strokes last longer and were superior to 2 strokes also, but I am reconsidering my opinion for several reasons:

1. "2 strokes rev higher than 4 strokes": false - 4,000 rpm on a 2 stroke is the same as 4,000 rpm on a 4 stroke, the only difference is that one has a power stroke on every stroke and the other every other stroke.

2. 2 strokes use new oil all the time, four strokes are using used oil that may possibly be out of viscosity range as it ages if it is not a quality oil, causing metal to metal contact. Additives can break down. Old oil can form sludge and clog oil passages. And small engines hold very little oil so it gets hot and can have thermal breakdown. The assumption with a 4 stroke is that if there's oil in there, then it has adequate lubrication - not true.

3. 2 stroke oil has come a long way since 30 weight motor oil was first used at high ratios like 16:1 New high quality oils run at 100:1 or leaner. 2 strokes last longer today because of better quality oils and are smokeless at the leaner mixes.

4. 4 strokes have a possibility of oil starvation - if a 2 stroke has fuel, it has lubrication

5. I adjusted the valves on a well known 4 stroke engine brand, and the metal holding the adjusting screws was brittle and snapped off. The engine had to be junked.

6. New 2 strokes are able to meet modern emission standards.

7. Between valve clearance adjustment on a 4 stroke, the engine is operating below optimum for a while until the valves are adjusted again. Many people don't want to mess with adjusting valves which can lead to engine damage.

8. 2 strokes have fewer moving parts to break.

So I'm seriously leaning towards purchasing a 2 stroke for my motorized bike.

 

[zean]

Hi Charlie Able. I have the tanaka PF 4000 on a staton-inc and one on a golden eagle kit, (it's too bad EZM doesn't make a kit for that type of clutch). The two stroke tanaka engine is very reliable and strong. I cannot say anything negative about this engine, it likes to run and do work. One is kind of loud, maybe the exhaust/engine junction has a small leak. I mean to tell you the tanaka is an excellent engine.

 

[Charlie Abel]

Thanks, the Tanaka is the engine I am considering - looks great!

 

[john7665]

Hi Charlie Able. My manual says printed in Japan, February 2004. I've read more than once the Robin Subaru manufacturing facility in Japan is a first class operation with excellent quality control.

I need belt for 2004 EH035 Subaru 4-stroke (bicycle w/motor mounted above rear wheel... just purchased). 64 inch belt. shredded after about a mile driving on straight street. I'm heart-broken. Went to Fuji site online. Saw nothing about replacing this long thin belt (lotta rubber teeth). John White 210-314-2883 San Antonio TX

 

[MotorBicycleRacing]

I need belt for 2004 EH035 Subaru 4-stroke (bicycle w/motor mounted above rear wheel... just purchased). 64 inch belt. shredded after about a mile driving on straight street. I'm heart-broken. Went to Fuji site online. Saw nothing about replacing this long thin belt (lotta rubber teeth). John White 210-314-2883 San Antonio TX

The 64" belt has nothing to do with your Subaru motor.

I guess you have a Golden Eagle kit which the drive belt comes with.
Belts are sold by www.bikeengines.com

 

[wayne z]

The Japanese are pretty conservative when it comes to engine replacing. In Japan, they tend to replace automotive engines before they make it to 100K miles.
These engines are often resold outside Japan for high performance use, advertised as "JDM" engines.

This early engine replacement is kind of ironic considering their high mileage reputation in the US.

The reason that we can buy cheap low time Japanese auto engines is because of their strict emissions laws.
When they reach 50,000 kilos, they are required to completly replace the entire emissions equipment at a large expense.
That and their propensity to "show good face", entices them to purchase a new car, and the old ones are scrapped, and the engines sent over here.

Back when I was into experimental planes, we were buying and converting the Subaru e-81's and the Geo 3cylinder engines. They were always in excellent mechanical shape.

 

[george_n_texas]

I have the same experience replacing engines in a Suburu wagon and a toyota pickup...they spin test the engines and have a graph showing the integrity of the engines. I bought mine in Garland Texas from East River pretty sure they are still in business. Nice thing about them engines is EVERYTHING bolted to the engine is generally included and there is no core to turn back in.