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Post by austin on Aug 7, 2017 9:27:11 GMT -5
pistonguy I checked more things and I believe the fuel is flowing better now. I was able to ride it without it cutting off. Also, while I know it won't cause my initial problem - would it have more air flow on a pod filter versus the foam filter?
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Post by austin on Aug 6, 2017 6:45:06 GMT -5
The Fuel Filter Maybe (most likely is) Directional, It should have a Arrow on the Fuel Filter Pointing to Direction of Flow. The plastic color sometimes makes it hard to see the Arrow. Going from the Foam filter you had to the pod Wont make that much difference or to cause the problem you have. Good Luck I was wondering about the air filter. I do have the fuel filter on the right way. It is directional and I installed it with the arrow pointing in the direction of the flow of the fuel. Just a quick question about the air filters, would the pod perhaps need a slightly different jet to reach peak performance - all things working properly? |
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Post by austin on Aug 5, 2017 17:34:03 GMT -5
That's what I was thinking. I thought I may have gotten some debris in my carb or needed to change to a larger main jet. I don't have any jets, but if you think it'll help - I'm all for buying a set of jets to try out.
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Post by austin on Aug 5, 2017 13:05:46 GMT -5
Hey there, I recently changed my scooters air filter and fuel filter. I also changed the fuel lines. Now the scooter will run for like 10 minutes before it dies. Before it dies, it'll cut out upon acceleration, but will idle and allow small amounts (barely turning throttle) of acceleration. After roughly 30 seconds to 1 minute, it doesn't even idle and will just cut off. I have to wait for it to cool down before it'll start again. When this happened, I checked the fuel line and it appears that there was only a very little in it. I checked and both the filters are installed properly and there wasn't any leaks around any of the fuel lines. I checked the valves and they are both at .004, which the scooter has ran fine like this for years - so I ruled that out. I checked the compression and it was 145 psi after 10-12 kicks (my battery needs replacing, so can't try via the starter). The compression doesn't really leak down as I waited 10-20 minutes and it was still around 140-145 on the gauge. It does have a 44 mm cylinder on it as well as a 18 mm carb w/ #  main jet. The new air filter is one of these: www.scrappydogscooters.com/images/342bb41c69a3a849c21276d7f33397e6_e7nc.jpg , and the new fuel filter is one of these: mobileimages.lowes.com/product/converted/037049/037049954841_05421931.jpg . I will say that the new fuel filter is likely 2x as big as the old one. I also changed the spark plug to rule that out, but that didn't change anything. The old filter was a foam one like this: www.scrappydogscooters.com/images/carb-filter-jet-package.jpgAny help or advice on what to check next would be appreciated. Thank you, |
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Post by austin on Sept 16, 2015 1:31:03 GMT -5
The ring gaps are not lined up. I made sure they were facing different directions. If I had to guess, I'd say the gaps are equally spaced apart like many of the digrams I could find. I believe I found the cause of the crankcase vent hose getting blown off. It was partially blocked, so I think the pressure just built up and forced it off.
I rechecked the oil with the scooter on the center stand and it appears to have remained normal since I unblocked the vent hose. I did get a new carb and air filter as well. I still need to check my spark plug now and see if it is still lean. I'll update this post once I perform that task. Thanks for all of the help!
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Post by austin on Sept 4, 2015 13:59:46 GMT -5
steve Well, now the problems start. It was running fine. It started acting up a little after about 30-40 miles (maybe km as the main denomination on the speedometer is km/h). It actually broke down today. It started having little power and slowed down until it stopped roughly 5 seconds later. It would restart and die upon cranking up. I decided not to try it and brought it home with a trailer I borrow from a friend. It doesn't appear to have any oil leaking anywhere and it had new oil, gas, gear oil, and fuel filter put on it when I rebuilt it. Any clue what I should check first? I was going to run a compression test once it cooled down some. EDIT: I ran a compression test. It is roughly the same (maybe a little lower, but not a lot) as it was after I rebuilt the top end. I checked the spark plug and it appears to be a little white, which I think means I'm running too lean. I also checked the oil level and the oil level dropped a decent amount from what it was when I changed it a few days ago. So I believe it is running lean and is blowing too much oil from the vent. It isn't leaking oil anywhere I can find after I inspected it, so my guess is the vapors are being caught in the air box or blowing into the air somehow. I haven't checked the airbox yet; however, the crankcase vent hose was disconnected. I know for sure that I reconnected it, so my guess is the pressure blew it off somehow.
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Post by austin on Aug 30, 2015 14:13:57 GMT -5
Well, I could be mistaken about the acceleration. I haven't been able to ride it in like 2 months, so I may be fuzzy about what it was like before the upgrade. Edit: Just wondering - I set my valves both at .004 inch according to several recommendations I found across the web. Is this acceptable in your opinion? steve |
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Post by austin on Aug 29, 2015 19:06:45 GMT -5
I like it so far. I haven't gone top speed yet. I was going to wait until it broke in a bit first. It seems to have more power; however, the acceleration is lower. That is probably because I have a slightly lower octane fuel in it right now. I've only gone around 15 miles. I was going to check the torque on the head bolts before my next ride. I'm also installing a new fuel guage sensor because the old one went out on me long ago. >_> The original one only lasted like 2 months.
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Post by austin on Aug 28, 2015 13:52:43 GMT -5
Sorry for the slow reply. My father passed away in the time I was going to change the cylinder and such. That caused a delay. Anyway - I changed the piston, rings, and cylinder. I put it all back together and changed the fuel filter and oil. It runs now. It doesn't smoke and doesn't make any noises that sound odd. Now just to change my gear oil so I can go for a short ride.
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Post by austin on Aug 13, 2015 9:02:34 GMT -5
steve Thank you for the help! Is 15w/40 oil what I need? That is what the dealer told me to put in it. I also need to change my gear oil - so 80w/  for that?
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Post by austin on Aug 12, 2015 16:40:04 GMT -5
I think I'm just going to stick with the 44mm bore for now. Will the other stock parts such as the fan and crankshaft be sufficient for the slightly larger bore in terms of life expectancy or should I look into replacing those in the near future as well?
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Post by austin on Aug 10, 2015 16:46:03 GMT -5
steve Thanks for the reply! I didn't know that about the rings. I'm going to order a replacement cylinder/piston/etc and install that when they come in. One question - would you recommend staying with the 39mm bore? I was thinking about upgrade to the 44mm one. I should have another comrpession gauge in my possession at that time as well, so I'll be able to check everything. I'll keep your other steps in mind should the cylinder and such not fix the problem.
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Post by austin on Aug 9, 2015 13:35:05 GMT -5
Well, the scooter wouldn't start up before I did the valve adjustment. I checked everything I could according to a service manual and checked the valves. The exhaust valve was way too tight according to all of the service manuals I read and according to all of the forums I read, which is why I adjusted it to .004. It was only then that it would start at all.
Once it stopped starting at all for the second time - I redid all of the tests according to the service manual's troubleshooting steps. This is when I found out that I may have low compression as it only showed roughly 65 psi with the guage and everywere I have read says it should be over 100 at least. I hope this resolves any issues I had originally detailing the problems.
Any suggestions on how to take the cap off of the carburetor screw? It doesn't easily come off, at least not by pulling on it with my fingers. XD I'm more than happy to try anything you guys think may get it running.
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Post by austin on Aug 7, 2015 13:33:21 GMT -5
Thanks for the reply! I don't believe that my carb would make me have low compression; however, I will check it anyway. I have a sealed carb and am unable to adjust the air/fuel mixture. The only setting I can adjust adside from disassemblying and checking jets would be the idle adjust screw. What exactly do you want me to check on it?
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Post by austin on Aug 6, 2015 21:36:25 GMT -5
Hey there,
I am new to the forums to please excuse me if I ask already answered questions. I have ran into some problems with my scooter. It is a 49.5cc Dykon JK50QT-A. The problems started when I was having starting issues. It would take a bit longer to start than new, which I figured was just the normal course of events with the battery. It finally got to where it would bog out and cut off after first starting the engine and riding a short distance. It would be fine one it warmed up.
Alright, so that was annoying enough. Near the end of the problems it begin to not start for like 20-30 minutes of kickstarting, which I knew wasn't normal. I checked the valves (scooter at around 1900-2000 km or miles as I'm not sure what it measures in since the speed it measured in km/h with mi/h in small font) and found the exhaust valve had almost no gap at all. I couldn't even fit a .002 inch guage in it and the intake valve was at .004, which I read is normal for it.
I readjusted the exhaust valve back to .004 inch and installed a new spark plug. The scooter started right up and I took it to the corner stop sign for a short road test. It ran fine and I thought the problems were gone as it no longer cutoff whenever I stopped after just starting the engine like I mentioned earlier. I dediced to take it for a about a 7 mile trip to a friends house to get my battery charged. Halfway through the trip - the scooter started slowing down and had no acceleration until it finally cut off.
I thought it was odd because I felt what seemed like an engine seize, but I wasn't sure as the gas wasn't exactly new. The scooter would not start back up for around 20 minutes. I got it started and continued my journey to no avail as the scooter cut off again a short distance down the road. This repeated one more time and then the engine wouldn't start at all or would cut off as soon as I tried to accelerate.
I pushed it to my friends house and let it set over night. I tried to start it in the morning to no avail and I was never able to get it to crank up again. I checked for spark, which is a good blue. I checked that it was getting gas, which it was to both the carb and cyclinder as the spark plug would be wet with gas. I rechecked the valves and tried the other recommended settings I could find, which proved futile.
I finally found a compression gauge and checked it. The highest reading I could get was around 65 psi. I took the valve cover, head, and cylinder off to check those next. I noticed little wear on the rings or cylinder in a visual inspection and by running my finger across them; however, I know this isn't exactly the recommened way to inspect them. I put those back together and checked the valves for leaks next. I looked up a way to checked them by pouting a solvent such as gas or alcohol into them.
I took the head completely off, so I assumed that both valves should be sealed shut. I poured the solvent into the intake valve an it didn't leak out of the other side; however, when I did it with the exhaust valve - it leaked a good amount. I purchased a new head w/ valve assembly to fix this along with new gaskets. I reinstalled all of them and put the engine back together along with the cooling shroud.
I tried starting the engine, but it still wouldn't crank at all. The engine would turn over seemingly fine and the timing was correct. I no longer had access to the compression guage, but I could feel a little more compression from the exhaust compared to the old head assembly. I believe I could have worn rings now or potentially a worn cylinder/piston. Does this sound plausible or am I completely off on my judgement?
Thank you and I appreciate any help you can give!
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main jet. The new air filter is one of these:
for that?