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Post by scooterfan86 on Nov 8, 2014 22:05:06 GMT -6
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Post by scooterfan86 on Nov 8, 2014 22:04:47 GMT -6
So I've taken the engine down to the head and replaced all the gaskets along with the valves and valve springs. A broken spring on the exhaust valve turned out to be the issue that needed dealing with. I am having an issue with the intake valve not opening up properly though. It is a new valve and springs up and down just fine with hand pressure, but when I close everything up and turn the flywheel by hand it rigidly binds on pushing the intake valve every time. There's no give at all, and no increase in pressure beforehand on the flywheel. I feel like I run into a piece of steel that won't budge. Having opened and closed and reopened things I've come to be sure that it is indeed the intake valve side of things not working right, but there doesn't appear to be anything rocker at all with the rocker arms or anything else. I put some white paint on the rocker arm pad and sure enough it lands spot on top of the intake valve.
And again, the valve moves freely just as the exhaust valve does with heavy hand pressure. It feels right, and everything looks right, so I'm stumped at what to do next. Any suggestions?
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Post by scooterfan86 on Oct 30, 2014 22:36:16 GMT -6
Each valve has 2 springs, an inner and an outer for a total of 4. The exhaust valve's inner spring was in 3 pieces. This seems very likely the cause of many of the problems.
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Post by scooterfan86 on Oct 29, 2014 13:21:55 GMT -6
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Post by scooterfan86 on Oct 26, 2014 14:12:10 GMT -6
And to be clear, at this point the engine starts, idles for a few seconds, comes close to 2000 rpm and then dies.. and to get that to happen the exhaust valve needs to be loose and rattling.. that sounds like a really good time to open it up and check things out and replace the valves but again any suggestions are appreciated.
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Post by scooterfan86 on Oct 26, 2014 14:09:52 GMT -6
Thanks alleyoop!The video is actually what I used when I originally adjusted the valves, but I think with the coolant problem things have gotten out of shape. I need to look into it at least before I feel comfortable riding any distance again.
It would be the valves to try replacing right? If they're warped or not seating properly they'd be the first thing to try to fix engine wise.. it that is where the problem is?
If anyone has recommendations as far as replacement valves and where to purchase them, or what tools I'd need that would be great information to have! I'd be cursing myself if I waited for parts only to find out they're the wrong ones haha.
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Post by scooterfan86 on Oct 26, 2014 13:26:27 GMT -6
The bolt for the exhaust valve adjustment is almost entirely to the right of where it can go. The engine only seems to turn over with a harsh rat-tat-tat coming from it like what's in the video when the bolt is loosened.. any further and it dies pretty quick... or at least this is what it was going yesterday. Right now it will start and get a bit over 2000 rpm and die. Thanks for all the advice from everyone.. I'm learning about all this as I go, trying not to make too many mistakes  It sounds like it could be a good time to open up the head and check out // replace the valves? I'll be sure to check that potentially pinched hose too but more and more seems to be pointing to the valves needing to be actually looked at//replaced. I've found potential replacements on a couple sites: .scooterparts4less.com/web_gas/4Stroke_Valve_set.htm" rel="nofollow" target="_blank"> .scooterparts4less.com/web_gas/4Stroke_Valve_set.htm (the CG 250cc Water Cooled Vertical Motor Valve assembly) and here: .scrappydogscooters.com/CF250_Water_cooled_parts.html" rel="nofollow" target="_blank">.scrappydogscooters.com/CF250_Water_cooled_parts.html (CF250 valve replacement set) Would either of these work for a 250cc Titan (aka the l-roar) by znen, or would you have any other recommendations as far as tracking down valves? I do have a Honda Helix shop manual that has what appears to be an identical engine, and have a couple other youtube videos showing replacing the valves (my dad has a mold injection factory so I do realize how important precision is when it comes to the engine). I would also need a spring compression tool of some kind right? Any recommendations or things I should try? Thanks again for all the replies, I really appreciate it. I'll look into that hose right now... it would be quite a relief if it was actually pinched in some way! |
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Post by scooterfan86 on Oct 25, 2014 22:59:54 GMT -6
When everything is up and running (which can still take some fiddling with the right valve adjustment), I'll rev the engine to nearly full capacity on the center stand.. going up to 9000 rpm and holding it there for several seconds, down to 5000 for around a minute, making sure the engine is warm. I'll do this a couple times. Then I'll put my gear on, open up my gate, go to take off and around 2000 rpm it dies. Sometimes I'll get up to 3000 or 4000 rpm going through the alley from my house, then come to a stop, and it dies. I've repeated this in its entirety within 15 minutes, dragging the bike back to my house, up on the stand, everything looks good again, then go and dies again.
Do you think it's likely purely mechanical then, or does the electrical effect what the load on the motor can take?
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Post by scooterfan86 on Oct 25, 2014 22:31:07 GMT -6
I'll definitely check it out in the morning Alleyoop, thanks for the advice. I think the picture gives the illusion of a pinched hose, where the bracket is actually above the hose entirely.
I also don't know if I'm making it clear that when I put the bike on the center stand, when I get things running I can reach very high rpms without any issues whatsoever. I don't see the center stand vs road conditions adding or subtracting any potential pinch to this hose... do you?
Could it somehow be possible that a valve or some other part of the engine seizes when in road conditions, while not being an issue at all on the center stand? There are still times when things don't start up and I have to fiddle with the right valve adjustment (what I've been told is the exhaust) to get it going. I'm still hoping someone will say the battery could be the real problem here lol, because that would be the easiest fix.
But yes, I'll get the plastic off again tomorrow and double check that hose, take more pictures, and get back to fiddling. Thanks for the advice, I really appreciate it!
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Post by scooterfan86 on Oct 25, 2014 22:05:39 GMT -6
The air box//filter assembly are off of the bike in this picture. They have been reattached. The radiator is under the front of the bike, and the pump, thermostat, and fan have all been working very well since I replaced the wiring to the temperature gauge.
The 'what is this a part of' does not go into anything as far as i can tel... it is held in place by a bracket bar and a bolt going through horizontally. I could take the bolt out and it wouldn't seem to affect anything else.
Can you give any advice on the bike working fine on the center stand and then dying on the road? I have had to tinker with the exhaust valve on the engine a couple times to get things going.. it still feels like it could be off by a hair.. but then again, my mind keeps going to the battery being short. I've got it on a trickle charger now to recoup from todays efforts and will try everything again in the morning.. but to have it die right out from under me, especially when it's running very well and into high rpms on the center stand, scares the s**t out of me. I don't get what's happening.
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Post by scooterfan86 on Oct 25, 2014 21:22:36 GMT -6
btw, here's the asked for picture with the mystery threaded bolt in the middle.. I'm still completely at a loss for what it's function is or what it could have connected to.  |
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Post by scooterfan86 on Oct 25, 2014 21:19:56 GMT -6
Ahhh, so frustrated with the bike right now. I'm really confused about an issue that's come up the last couple days while I'm working on it. I've gotten everything started up just fine, cranking the engine into 8-9000 rpm on the center stand. The cooling system is working as it should now. There was a loose wire that needed to be replaced in the temperature gauge assembly and with that fixed the rest of it bumped back into action. The problem is, even with the bike warmed up, just rolled into the 9000 rpms with no issues on the center stand, I go to pull out and drive and either right away or at a stop the engine stalls out upon acceleration. Repeatedly. To the point where I wheel the bike home and put it back up on the center stand and again, full swing of the throttle, everything looks perfect and again, go to take off and chug, chug, die. I thought this was a valve issue or possibly something freezing up in my engine.. but could this be the case with what I've described? My battery was just replaced, and my brother was kind enough to get me one with his fancy discount through work.. the CCA are fine but the battery itself is an amp short of my original one. Since the CCA's weren't good in the old one, he gave it to his contact for disposal. Could the half amp shortage be doing what I'm talking about here? I was thinking this was a serious mechanical problem, but after having it running so well on the center stand and to have it die with the ground under it.. it feels like it could be a juice problem. Does anyone know, or has anyone dealt with something like this before? I'd sure like to be back on the road again.. it's been a rough couple weeks working on this  |
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Post by scooterfan86 on Oct 19, 2014 18:28:56 GMT -6
And just to be clear, the scooter is starting and running and this does not go into anything on the other end, just held in place by a diagonal bolt going through the head.
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Post by scooterfan86 on Oct 19, 2014 18:23:07 GMT -6
Thanks for the responses, I'll be getting the carb//valves to where they need to be and try to see if burping the cooling system will work. ![]() I came across this bolt after taking the plastic off of the bike. It's just above the starter motor under the front of the seat, pointing forward on the bike. I can't for the life of me figure out what this screwed into, or what it's purpose could be. So far I can't find any other threads or places for something to be attached.. any ideas of what went here and how I'd go about replacing it? In any case loctite would definitely be part of the equation! The other end of the bolt is held in place by another bolt going through it's side, giving it some wiggle, almost like a hinge. I can get more pictures if needed.  |
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Post by scooterfan86 on Oct 14, 2014 17:58:06 GMT -6
Hi there, thanks for all of the great articles on here! They've been very helpful in keeping my 250cc liquid cooled Titan (also known as the L-Roar) going for the last 2500 miles. I have come up to some issues that I would love the boards input on. All of these problems have occurred in the last week. The bike has a very hard start, where the engine needs to be warmed up for it to ignite. I think this could be a valve adjustment issue, but as of yet have not had luck in getting everything back to normal just through adjusting the valves or the idle screw. It has a new battery and a new spark plug, plenty of gas and plenty of coolant. The old battery was more dead than it should be, and I could have put some wear and tear into the electronic system by doing this. The coolant will not always flow though. The thermostat literally doesn't kick in, but then other times it does just fine. I've also noticed the temperature gage is very much out of wack, with it reading very hot when I've just run the bike around town. I've also had two occasions where the bike died while it was running at a stop, where I went to accelerate and the engine just completely went out needing to be restarted. And finally, there was a time when I went to start up the bike, and all the electronics went dead. Turning the key back and waiting a minute re-engaged the electronics, and it started as normal afterwords. It felt like a grounding or crossed wire issue but I could be wrong. Again, these are all within the last week, and outside of the problems the bike runs very well, nice smooth idle, a little bumpy in the first bit of acceleration but it has always been that way when the belt switches from low to high speed. I'm going to be taking the plastic off and begin looking for the problem(s). Any suggestions? My first thought is an electrical issue since when the bike is running it's running fine. The need to warm the engine first makes me nervous since it could be an engine compression issue that would be a monster to fix.. but could the hard starting also have an electronic basis? Any information would be helpful.. I realize it sounds like this post is all over the place but I'm hoping to be able get my ride back to where its the reliable scooter I know and love  Cheers. |
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