if it dies out after a couple min run time then insure proper fuel flow from tank and that it is vented properly.. there is a screen in the fuel petcock as well you know.
you can check the float level, but to some extent this is a normal limitation of a carburetor and simply requires some clearing revs to prevent stalling or perhaps a bit higher idle
trapezeartist: Yep I'm not too concerned about the clutch drag! Totally liveable.
Nebulous: The reeds all look fine. I'm not familiar with 2 strokes really, so am unsure if the reeds should always be slightly open, or if this is a fault.
copemech: I'll revisit the fuel screw when I get back to the bike. Good point about the heavy flywheel, makes sense! Should the reeds always be slightly open? For engine idle speed perhaps?
Thanks!
reeds may not seal perfectly , yet when under backpressure they will !
it needs more fuel, most all dellortos run maxed at 3.5 turns
Hi folks, thanks so much for your superb advice and suggestions. I stripped the carb just now, the inlet fuel filter had some crap in it but nothing major. All passages were clean and clear. Jets are:
Pilot 37, main 270, drain bolt says 110, and the one with the o-ring says either 60 or 80.
A 37 pilot is fine. the Main is the one you are calling drain bolt. Needs to be 120 ish.
Drained the fuel, it looked clean. Going to refill with fresh. The fuel screw was exactly 2 turns out, I have set it back to that and will experiment with it next time I start her up. I didn't remove the reed block but it feels supple and visual inspection yields no cracks or splits. The tank breather is free and clear but the fuel flows pretty slowly out of the tap. Might just be normal though, it certainly flows fast enough for the bike to run. Would old fuel result in the engine running lean?
Three or more turns out on the fuel screw. That may be your main issue! The heavy flywheel will take a bit longer to wind down but your is a bit floaty and surging.
I popped the ignition cover to have a quick look, the flywheel is enormous! And a bit rusty. Water has got in there at some point.
Drill a 3mm hole in the bottom so water can exit and vent.
On an unrelated note, the clutch drags with the lever held in the first time I put it into gear after starting. The clutch drag goes away almost immediately.
How quickly should the revs return to idle after a blip of the throttle? Straight away? I'll keep you updated. If my efforts with the carb don't work, is the next step to pull the flywheel and replace crank seal?
Not straight away! Put the reeds back init and leave them alone.
Clean the carb properly and insure proper jet sizes. Should be around 38 pilot and 122 main jet. Find a strand of copper wire to pass through the jets for verification. The fuel screw will be out 3.5 turns or so. Needle one notch below center.
Crank seals are removed from outside, but do not go there as yet.
I recently added a trail tech in coolant temperature sensor to my 2014 Ossa TRi 250, I am seeing coolant temperatures of 220 to 230 degrees F during extended climbs of 1000 to 2000 feet at 5000 ft elevation. Can any Ossa owners confirm the coolant temperatures they see during high load operation. New cooling fan, radiator clean, fan relay good, fan turns on at about 160 and off at 155. No lifting of radiator cap relief, idle speed drops about 200 rpm at elevated temperature. See coolant temperatures of about 150 to 170 during normal trials riding activity.
nothing ossa specific, but sounds about right for most any trials bike. you are limited with trials radiators though, as they are not made for hard running like an enduro
I have listened to this and it is not apparent the issue, as they all rattle and worse sitting in neutral while revving. does it reduce when the clutch is in and in gear? there will be some rattle in the primary drive gears as well when unloaded.
So you did check the banjo screen on the side of carb?
All jets clear, really? How did you verify?
Remove carb when this is occurring and break the bowl seal over a clear vessel. Look at volume of fuel, ck for water settling and dirt in your sample catch.
RL250 carb adjustment
in Suzuki/Beamish
Posted
if it dies out after a couple min run time then insure proper fuel flow from tank and that it is vented properly.. there is a screen in the fuel petcock as well you know.