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Post by scooterollie on Aug 13, 2006 21:26:30 GMT -5
I have encountered the first major problem with my Roketa Bali 250. After a few mile ride yesterday, hot re-starts were not instant as they always were. I had to crank the engine over a few seconds and open the throttle. When it would start, it acted like it was flooded. This occurred each of the few times I had to hot re-start. Could also smell gas. Put the scoot away for the night and pondered the problem that evening and this A.M. Thought maybe the enricher was malfunctioning.
This afternoon, scoot started up cold instantly and idled OK for a couple of minutes. Took off down the road 1/2 mile on an errand. Part way there the scoot began to stall out every time I would let up on the throttle. It would pick back up if I worked the throttle. Got to my destination and it stalled as I came to a stop. Stronger smell of gas. Finished my business and got it re-started by cranking and opening throttle full wide to overcome what appeared to be flooding. Could keep it running if I was under heavy throttle. Made it back home. Scoot stalled out and the smell of gas was strong. Even had raw gas dripping off the bottom of the engine. Pulled cover off over the carb but could not see anything wrong. Got down on my back and looked up under and to the right side of the engine/carb but still couldn't see anything wrong.
Beginning to feel that maybe the float or needle valve has a problem. What do you all think?
Stan, you have a lot of experience with this bike and the carb. What do you think. Will I have to remove some body panels, air filter, & induction hoses to get at the carb and take it off? Have seen a number of comments on sticking floats. Sure doesn't seem like a fuel starvation problem!
Other than the observations, haven't had time this evening to begin trouble shooting.
Thanks all!
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Post by 90GTVert on Aug 13, 2006 22:34:47 GMT -5
That's exactly how mine acted when the manifold gave it up. Low R's would allow the split to open but the suction under power sealed it up enough to run ok. Fire it up and wiggle the carb. You just need to remove the air box and the snorkle, which can be done through the under seat hatch. From there, it's just a hose clamp and hoses to get it off. The manifold is a little tougher because of the tight bend, but not too bad. Stan I have encountered the first major problem with my Roketa Bali 250. After a few mile ride yesterday, hot re-starts were not instant as they always were. I had to crank the engine over a few seconds and open the throttle. When it would start, it acted like it was flooded. This occurred each of the few times I had to hot re-start. Could also smell gas. Put the scoot away for the night and pondered the problem that evening and this A.M. Thought maybe the enricher was malfunctioning. This afternoon, scoot started up cold instantly and idled OK for a couple of minutes. Took off down the road 1/2 mile on an errand. Part way there the scoot began to stall out every time I would let up on the throttle. It would pick back up if I worked the throttle. Got to my destination and it stalled as I came to a stop. Stronger smell of gas. Finished my business and got it re-started by cranking and opening throttle full wide to overcome what appeared to be flooding. Could keep it running if I was under heavy throttle. Made it back home. Scoot stalled out and the smell of gas was strong. Even had raw gas dripping off the bottom of the engine. Pulled cover off over the carb but could not see anything wrong. Got down on my back and looked up under and to the right side of the engine/carb but still couldn't see anything wrong. Beginning to feel that maybe the float or needle valve has a problem. What do you all think? There is a clearish plastic hose that ends at the bottom, left front of the engine. Is this a carb overflow/vent hose? Can't see what it attaches to up in the front of the engine. No gas coming from it, though. Stan, you have a lot of experience with this bike and the carb. What do you think. Will I have to remove some body panels, air filter, & induction hoses to get at the carb and take it off? Have seen a number of comments on sticking floats. Sure doesn't seem like a fuel starvation problem! Other than the observations, haven't had time this evening to begin trouble shooting. Thanks all! |
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Post by scooterollie on Aug 14, 2006 8:09:58 GMT -5
Stan;
Thanks for the reply and info. That is really interesting. You actually had gas leaking? Did you see any difference if you wiggled the carb/manifold as it was running?
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Post by 90GTVert on Aug 14, 2006 8:57:52 GMT -5
Mine split bad enough that when I stopped, there was no starting it again. I was about 1-1/2 blocks from home, so I pushed it. Yes, I did smell gas (but no leak) when I stopped since the engine was still turning, fuel was moving but there was way too much air to allow it to run because of the split in the manifold. When I removed it, the manifold had split about 2/3 of the diameter. Way too big a gap to be very sporadic, so it just gave up. I'll be interested in hearing what you find as the cause on yours. Oh, one good thing about building a straight manifold is that I can now get to the mixture screw on the 32mm carb to adjust it while running! I haven't checked, but I believe this carb may also be one of those that the mixture screw is reverse of the norm. Stan Stan; Thanks for the reply and info. That is really interesting. You actually had gas leaking? Did you see any difference if you wiggled the carb/manifold as it was running? |
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Post by scooterollie on Aug 14, 2006 9:08:13 GMT -5
Stan;
Thanks. Mine was clearly dripping gas from the bottom of the engine. Could see that gas was running down the front of the engine from above but the view was obscured. Probably won't get to it today because of other obligations. Will let you know.
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Post by scooterollie on Aug 14, 2006 10:18:29 GMT -5
Had a few minutes this morning to investigate more thoroughly. Started the scoot cold. Had to crack open the throttle to get it started and it wouldn't idle. Wiggled the carb/intake severely with no difference. Within a few seconds gas started pouring down the right side of the engine. I moved other things away obscuring a view of the carb and on the right side of the carb, just below the domed top and forward of the enricher there is a short L-shaped hose - looks like a drain. Gas pours out from this hose when the scoot is running. Internal carb problem - stuck float or needle valve, or something else? Started two days ago. Each time I ran the scoot, the problem was more severe.
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Post by scooterollie on Aug 15, 2006 14:31:39 GMT -5
Don't you hate it when there is an obvious problem with what should be an obvious cause? Removed the carb today and thoroughly inspected it. Fully expected to find an obvious cause for gas gushing out the float bowl vent. NOTHING! NADA! ZILCH! Inspected float, float valve, CV piston and diaphragm (probably not proper terminology). Cleaned all passages, orifices, etc. and blew air through them. Reassembled and started it up. Runs fine, no flooding or gas expulsion. Could have been a very small speck of dirt that was dislodged by the cleaning. What do you think guys?
While things were apart I corrected some additional poor assembly items:
-Radiator cap fill neck was touching the air intake duct going to the carb and beginning to rub the plastic. Bent the metal tab welded to a frame member, that secures the neck, to give more clearance.
-Coolant recovery/overflow tank was touching the large metal washer at the end of the big rubber engine vibration dampener. Didn't want it to rub a hole in the tank. Bent the metal arms the tank is bolted to, slightly repositioning the tank for more clearance.
-Found another hose attached to the carb that was missing a clamp.
Carefully inspected the rubber/metal intake manifold as per Stan's suggestion. No sign of cracks yet. Giving more clearance between the radiator fill neck and air intake, the carb can now wiggle around more when the engine is running. Can see why it fails so fast. Guess I better order another and hope for a cast metal upgrade replacement.
Biggest problem taking the carb off was getting to the screw heads of the band clamps. They were positioned during assembly so no human could ever get at the screws to loosen the clamps! They are now all accessible for future removal. Isn't it interesting that what failed and disabled the CHINESE scoot was a JAPANESE part!
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Post by 90GTVert on Aug 17, 2006 8:06:13 GMT -5
I ordered and received a new radiator fill neck and manifold from Honda and they are a perfect match. The part numbers ar on my site in the sheet on Part Numbers for Common Items. Stan Don't you hate it when there is an obvious problem with what should be an obvious cause? Removed the carb today and thoroughly inspected it. Fully expected to find an obvious cause for gas gushing out the float bowl vent. NOTHING! NADA! ZILCH! Inspected float, float valve, CV piston and diaphragm (probably not proper terminology). Cleaned all passages, orifices, etc. and blew air through them. Reassembled and started it up. Runs fine, no flooding or gas expulsion. Could have been a very small speck of dirt that was dislodged by the cleaning. What do you think guys? While things were apart I corrected some additional poor assembly items: -Radiator cap fill neck was touching the air intake duct going to the carb and beginning to rub the plastic. Bent the metal tab welded to a frame member, that secures the neck, to give more clearance. -Coolant recovery/overflow tank was touching the large metal washer at the end of the big rubber engine vibration dampener. Didn't want it to rub a hole in the tank. Bent the metal arms the tank is bolted to, slightly repositioning the tank for more clearance. -Found another hose attached to the carb that was missing a clamp. Carefully inspected the rubber/metal intake manifold as per Stan's suggestion. No sign of cracks yet. Giving more clearance between the radiator fill neck and air intake, the carb can now wiggle around more when the engine is running. Can see why it fails so fast. Guess I better order another and hope for a cast metal upgrade replacement. Biggest problem taking the carb off was getting to the screw heads of the band clamps. They were positioned during assembly so no human could ever get at the screws to loosen the clamps! They are now all accessible for future removal. Isn't it interesting that what failed and disabled the CHINESE scoot was a JAPANESE part! |
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Post by scooterollie on Aug 17, 2006 8:40:04 GMT -5
Stan;
Good news! Think I'll order a spare manifold. Scoot seems to be running fine. Put another 50+ KMs on it since the carb R&R. Initially turned the mixture screw in about 1/8th turn and did not like the change. Removed card again - have gotten real good at that, 10 minutes! - and turned it out 1/8 past stock setting. Seems very smooth and purrs real nice.
Noticed your posting on valve adjustment. Thanks. Was wondering about that. Is that all there is? No checking w/feeler gauge? Seems too simple! Did you check yours? Was it off?
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Post by 90GTVert on Aug 17, 2006 8:55:50 GMT -5
No, I haven't checked mine yet, but I did find it interesteing that the article (CF Moto) says the gap is (.10mm) .004" when set, but the Tank label says to set them at (.03mm) .0012" intake and (.18mm) .007" exhaust. Since the Tank engine is the CF Moto engine, why the difference? Gotta love the consistency in Chinese information, eh? Stan Stan; Good news! Think I'll order a spare manifold. Scoot seems to be running fine. Put another 50+ KMs on it since the carb R&R. Initially turned the mixture screw in about 1/8th turn and did not like the change. Removed card again - have gotten real good at that, 10 minutes! - and turned it out 1/8 past stock setting. Seems very smooth and purrs real nice. Noticed your posting on valve adjustment. Thanks. Was wondering about that. Is that all there is? No checking w/feeler gauge? Seems too simple! Did you check yours? Was it off? |
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Post by Admin on Aug 17, 2006 13:29:16 GMT -5
Just split the difference and set it somewhere in the middle. ;D
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