GEBE R/S 35: Am I running too rich?

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Cowled_Wolfe

Guest
Hey ya'll. Right now, I think my engine might be running too rich, or perhaps my carb is dirty (I'm the mount kit's second owner, but the engine's third owner!).

Here's a list of symptoms:

  • My top speed is only 20-22MPH on the flat, with no winds (I'm 190lbs, and I haul maybe 20lbs of gear). That's with a 12-tooth gear.
  • I never need choke for a cold start.
  • The engine idles very nicely when cold, but once it warms up I have to give it a little throttle to keep it from dying (enough that I can hear the clutch lightly rubbing).
  • To re-start the warm engine, I need to apply a bit of throttle while pulling the starter cord.

I'm going to be running some carb cleaner in my next bit of fuel to see if that helps, but I think for a full fix I need to adjust my richness. Does anyone know how to do that on an R/S 35?

Alternately, what else could be the culprit?

Cheers,
Wolfe.
 


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OldPete

Guest
Have these symptoms been present since you first started using this R/S 35??

If so...someone has drilled the main jet or the airfilter is increadably dirty.
 
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Cowled_Wolfe

Guest
Yeah, they've been present from the day I got the engine. I just looked at the air filter and found it incredibly wet with an oily compound -- I've just blown it out, but haven't test-run the engine yet. Right now I'm cleaning the spark plug (I think it's been neglected).

Also, there's a bit of carb cleaner now in my tank.

When I'm back from work tonight, I'll post any improvements.

By the way, what sort of speeds are "average" for the R/S 35? I'd like to judge my speed against others', as a rough performance metric.

Cheers,
Wolfe.
 
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OldPete

Guest
28~30mph with #12.

Neglected? Might want to check the valve clearence.

Is the crankcase breather tube blowing oil onto the a/f. If so that would mean piston ring blow-by or the crankcase was over-filled with oil. When these motors are used on hard-tail bicycles the oil level should be kept near the low level mark NOTthe high level mark(as per Julia of GEBE).
 
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sabrewalt

Guest
Max Speeds RS/35

My new kit got top speed on a flat is 26-28 mph. I don't like that speed but the reserve is good for hills. I am 250 lbs and I have knobby mtn tires. So a tire change and 50 lbs of weight removal would easily yield book values.
 
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Cowled_Wolfe

Guest
The plug looked pretty good. Today I actually think performance went up a bit. The idle was rough, but better... And I had to use choke to start it! That's a first for me.

If I had to guess, it's because I'm running the carb cleaner and because I lowered the oil level.

Either way, I'll post if thins change (or if they don't).

Cheers,
Wolfe.
 
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Roy Carpenter

Guest
Yeah Cowled Wolfe, believe it or not, I weigh in at around 345, and running fairly fast tread street tires, (26X2.125), w/mr tuffy liners. I used to get 31 mph on flats w/o wind, and since installing the tuffys, (with standard gear), I get 29 or 30mph....depending on her mood...lol. R/S 35 with about 750 miles on 'er. And definitely keep the oil level on, or just very slightly above the lower level mark. Any more than that means an oily engine, and air cleaner. Oh by the way....you can download an owner's manual, and service manual for that Robin online. I can't find the link right now, but just put "Robin/Suburu EHO35 manual" into your favorite internet explorer, and you'll find the downloads without much dificulty. The manuals are in PDF format, and are read with Adobe acrobat reader. The service manual is real nice;)
 
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