Subaru driving me nuts !

robin · Jan 19, 2011

I have a Subaru robin 35cc with almost 200 hours on it. I thought i was getting carp in the carberetor so i put on a Dubro 1/8" line fuel filter. My mechanic disassembled it 3 times at 2 different times and it ran fine for about 10 hours then the same old problem- you can rev out to about 1/3 of its capacity only then if you dont back off on throttle it will die.I also tried another plug.
I moved away from this mechanic and so i bought another carb and poo the same problem. So then i thought maybe its the coil and a new one came today. It is set 100 mills above the flywheel and i also tried other settings- still carpy performance ! So now i dont know im not a mechanic but the service guide says adjust the valves every 200 hours - i need a mechanic to do that but do you guys need a valve setting every 200 hours? or do you have to clean the exhaust port ? would the 2 stroke Tanaka be less maintenance?

scotto- · Jan 19, 2011

robin said:
I have a Subaru robin 35cc with almost 200 hours on it. I thought i was getting carp in the carberetor so i put on a Dubro 1/8" line fuel filter. My mechanic disassembled it 3 times at 2 different times and it ran fine for about 10 hours then the same old problem- you can rev out to about 1/3 of its capacity only then if you dont back off on throttle it will die.I also tried another plug.
I moved away from this mechanic and so i bought another carb and poo the same problem. So then i thought maybe its the coil and a new one came today. It is set 100 mills above the flywheel and i also tried other settings- still carpy performance ! So now i dont know im not a mechanic but the service guide says adjust the valves every 200 hours - i need a mechanic to do that but do you guys need a valve setting every 200 hours? or do you have to clean the exhaust port ? would the 2 stroke Tanaka be less maintenance?

I wouldn't worry too much about carbon build-up in the exhaust port but the valves could certainly use an adjustment with that many hours on the engine. I'm sure you can find the specs for adjustment online. The Tanaka would require the same maintanence as your Subaru.....less the valve adjustments and oil changes.

Goat Herder · Jan 19, 2011

While I am not familiar with your motor or carb per say. This scenario sounds like fuel starvation to me? Might read this? In adiquit flow? Venting at fuel cap/tank? Pet cock might have a tiny orifice to it that may be clogging? http://motorbicycling.com/f34/your-bike-losing-power-top-speed-24880.html

Stuff like float bowl set too low? I would perhaps look at your fuel delivery first because some of these Chinese carbs are so finicky at the float. I also found I like to gently arch my metal tangs at the float this permits the float to better center itself and makes for more better proper leverage at the needle valve as a result.

robin · Jan 20, 2011

Wow its now running smooth and powerful - got the valves done today and a new fuel tank scintered brass filter . Maybe it was the filter all along but the valves needed adjusting anyway as it actually has about 210 or more hours on the engine. . I may have wasted the money on the carb and coil but it would have cost me that much in labor locally as here it is a very expensive hourly rate. I took it to my original mechanic. Anyway im happy to be able to pull the hills and go fast again ! Well its a learning experience and thats what makes this hobby fun - go from frustration to exilleration !

thatsdax · Jan 20, 2011

Good Deal Robin. I mentioned to a guy today who is having a similar problem with his 4 stroke. He did say he has a few thousand miles on his Titan and it is stumbling now at higher revs. He has pulled and cleaned his carb 2 times with no joy. After some q and answers, I found out that he has never checked or adjusted his valves. Never !! I stressed to him how important this is !! Not having proper valve gap could allow valves to float and then carbon build up on seats and could even burn the seats as well. Or even the other way with too much gap and tap dancing. Either way, not good. Every one with a OHV 4 stroke should check their valve clearance at break in which is around 200 miles or so. Then again at 1000 miles.. And then once every 2 years there after. But they need to be checked right at or before break in for sure !! Super important !! Enjoy the ride..........

robin · Jan 20, 2011

thatsdax said:
Good Deal Robin. I mentioned to a guy today who is having a similar problem with his 4 stroke. He did say he has a few thousand miles on his Titan and it is stumbling now at higher revs. He has pulled and cleaned his carb 2 times with no joy. After some q and answers, I found out that he has never checked or adjusted his valves. Never !! I stressed to him how important this is !! Not having proper valve gap could allow valves to float and then carbon build up on seats and could even burn the seats as well. Or even the other way with too much gap and tap dancing. Either way, not good. Every one with a OHV 4 stroke should check their valve clearance at break in which is around 200 miles or so. Then again at 1000 miles.. And then once every 2 years there after. But they need to be checked right at or before break in for sure !! Super important !! Enjoy the ride..........

Thanks i was coming alwfully close to ordering one of your engines because the price is right for the 4 strokes and from what i read yours are the best for the price. I wasnt wanting to sink excessive funds really like 300 for a Tanaka which is 40cc compared to your 50cc engines.

Dan · Jan 21, 2011

Cool, glad your up an' running again Robin. I was thinking it was a problem with ethanol.

Can't find any Efree fuel here in CT. As a last resort, gonna try local airport. After that, can only buy a 55 Gallon drum. Any one wanna buy some gas? lol

Search

Subaru driving me nuts !

robin

Member

scotto-

Custom 4-Stroke Bike Builder

Goat Herder

Gutter Rider

robin

Member

thatsdax

Member

robin

Member

Dan

Staff