|
|
Post by neo on Jul 25, 2016 20:39:13 GMT 1
Hi all, not posted for a while but asking for help and advice if poss... my 350 lc is all there apart from the hesitation about 5300 ish to 6k it's not like I hit a wall and it won't pass I can coax it through.. Is this the lc "character" as many report this.. Brief sp... 250 conversion with standard pipes, b8s, 220 mains 22.5 pilots, standard air box filter and all foam seals in place, needle clip centre position, carbs in sync, mixtures 1.5 out not that this matters I shouldn't think.. No leaks of air or on exhaust side.. Not checked reeds or timing.. Other than that she's sweet, still running in done 200miles atm taken to 7k a few times but concentrating on various throttle positions and heat cycles more than constant Mile munching 1982 later barrels standard bore 4l1 00 carbs (have a spare pair of old 4lo 01 s I fitted but they must need a clean as it ran like a pig
Many many thanks in advance
|
|
|
|
Post by markhoopy on Jul 25, 2016 23:20:22 GMT 1
|
|
|
|
Post by Bozzy on Jul 26, 2016 1:28:18 GMT 1
or try dropping the needle one notch my YPVS had issues for ages modern petrol. Dropping needle one notch made loads of difference. IT was hesitating 5 to 6k
|
|
|
|
Post by Eyrey1 on Jul 26, 2016 1:39:52 GMT 1
send the complete 4lo carbs to muttsnutts and ask him to do a full service on them
and set them up
you know they will be right then and it should run propperly after that you will get them back within a week and i think its 40 or 50 quid well spent
he drills the little brass balls out and clears the airways that can get blocked
|
|
|
|
Post by neo on Jul 26, 2016 6:36:42 GMT 1
Thanks all! Will try the needle clip position , did try muttsnutts about a year or two ago for my old lc carbs but he couldn't do it as was inundated but will try again, I'm also going to try super unleaded next tank full as I have heard running standard can cause problems long run.. Thanks again for all your help
|
|
|
|
Post by rigga on Jul 26, 2016 8:37:25 GMT 1
Several things cleared my midrange up completely, no hesitation at all now, revs fly round in all gears
Dropping needle to second from top
Early 00 Carb needles in 31k carbs (4h16)
Removed snorkel
Drilling holes in airbox lid
Main jets now 260 (240 standard)
All on a 350 4l0 pleasure to ride now
|
|
|
|
Post by neo on Jul 26, 2016 19:19:32 GMT 1
Thanks rigga I'll have a play, I have raised clip one notch as 5300 - 6k pretty bad and that's around national speed limit so really makes riding it a faff
|
|
|
|
Post by neo on Jul 26, 2016 22:44:41 GMT 1
Thanks rigga I'll have a play, I have raised clip one notch as 5300 - 6k pretty bad and that's around national speed limit so really makes riding it a faff Nb I have not yet tried it since the above post so will post up once tried (rain forecast AGAIN) |
|
|
|
Post by neo on Jul 27, 2016 20:30:29 GMT 1
Ok
Almost alleviated the problem it's passable now I did drop the needles to the lowest point but I gained vaugeness around 3500 and completely lost 5300 rpm hesitation so I went back to down clip position 2 (from the top) I did try a small washer making it about 1.5 which also gave good results but didn't feel that the needle was seated correctly under the needle holder so gone back to position 2 may get some new needles and emulsion tubes at some point do I go standard emulsions and standard needles or 4h16 needles as Rigga suggested ... Thanks for all your help
|
|
|
|
Post by 4l04ever on Jul 27, 2016 22:30:03 GMT 1
I resolved the issue on my LC by modifying the airbox lid. Running standard 4L0-01 carbs with needle on middle clip.
I replaced the snorkel with a lot larger version :-)
|
|
|
|
Post by Bozzy on Jul 28, 2016 0:08:17 GMT 1
Its getting obvious that its getting more typical for problems with jetting now due to crap petrol and having to drop needle positions. what is worrying is we used to be 5% ethanol now it 7.5% and soon 10% will be allowed which is going to cause us major issues... only petrol that has zero ethanol which I always get when possible is Esso Super Unleaded.
Now if anyone would like to help me with the leaking LC2 (see post) much appreciated a its driving me crazy and I cannot find a solution.
|
|
|
|
Post by neo on Jul 28, 2016 6:56:40 GMT 1
Thanks for all your help initially the bike had no air filter and microns and no snorkel in the air filter and no foam seal between top and bottom part of air box or under the lid so I replaced all these to make it like it came out the factory but think it may have aggravated the problem so may try removing air filter again to experiment
|
|
|
|
Post by hardhatharry on Jul 28, 2016 9:53:50 GMT 1
You need a fatter needle, next size up fixed mine
|
|
|
|
Post by neo on Jul 28, 2016 19:18:26 GMT 1
You need a fatter needle, next size up fixed mine Cheers Harry I got 5k1-3 s in atm |
|
|
|
Post by neo on Jul 31, 2016 14:31:03 GMT 1
Does anyone reckon my Reed valves could be faulty? Dropped needle x1 clip to lean off and the hesitation is better I'd say 5700-6k not whipped them out yet to check not sure what the symptoms of goosed reeds are... Shes all spot on other than the hesitation.. In respect of starting and general running throttle position in any other part of the rev range is all fine it's just then the revs reach this area which is kinda twisting my melon
|
|
|
|
Post by rigga on Jul 31, 2016 17:16:14 GMT 1
Its running rich at that point when it transitions to the main jet, so need to reduce the fuel at that point, its helped by you dropping the needle as the thicker part of the taper then reduces the fuel being drawn up the emulsion tube, so either fit a different shape needle, or increase the available air throughout the rev range, and compensate by increasing the main jet to keep the mixture safe
|
|
|
|
Post by neo on Jul 31, 2016 17:25:40 GMT 1
Its running rich at that point when it transitions to the main jet, so need to reduce the fuel at that point, its helped by you dropping the needle as the thicker part of the taper then reduces the fuel being drawn up the emulsion tube, so either fit a different shape needle, or increase the available air throughout the rev range, and compensate by increasing the main jet to keep the mixture safe Cheers rigga, I'm on the phone to Allen's performance first thing for thicker needle and interesting point about the main jet enlargement many thanks |
|
|
|
Post by neo on Aug 1, 2016 22:27:32 GMT 1
Ok pulled reeds today.... Not good! I could see daylight between the tip of the petals and the cage on top and bottom on both pairs, the reeds themselves were nasty plastic sheet just one solid square not seperate petals this will not help it at all!
|
|
|
|
Post by neo on Aug 3, 2016 17:51:59 GMT 1
RIGHT!!! Problem solved!!!!! Amazing and I mean proper revelation ..... New reeds new reed cages... Enough said, wasn't jets, needles, emulsions, needle position, needle thickness, blocked airways... just the reeds... Super smooth off the nail right through no hesitation no vaugeness even feels smoother so... Anyone experiencing similar issues CHECK YOUR REEDS! thanks for all your help I'm going to try to enjoy my 2 stroke now at last.
|
|
|
|
Post by LC_BOTT on Aug 3, 2016 18:06:17 GMT 1
Glad you got it sorted, I'm sure we all read this type of thread avidly, cos it was just assumed 'they all do it' Even back when mine was new there was always a flat spot, it was just accepted because you knew what joy was coming, once you got through it  |
|
|
|
Post by neo on Aug 3, 2016 18:19:50 GMT 1
Glad you got it sorted, I'm sure we all read this type of thread avidly, cos it was just assumed 'they all do it' Even back when mine was new there was always a flat spot, it was just accepted because you knew what joy was coming, once you got through it Agreed I was almost at the point of just accepting they all did that but honestly I can't believe it its just so smooth no flat spot no hesitation no vagueness just pics up evenly and smoothly all through the Rev range I just completely forgot about the reeds for some reason |
|
|
|
Post by wallcraft on Aug 4, 2016 20:11:56 GMT 1
Result.
What reeds you runin.
|
|
|
|
Post by neo on Aug 4, 2016 21:14:31 GMT 1
Result. What reeds you runin. Completely standard cages and petals |
|
|
|
Post by steven on Aug 4, 2016 21:25:45 GMT 1
...... Quack test ! rdlccrazy.proboards.com/thread/21885/fibre-reeds-seating-problemsI faffed about for ages with my reeds. I could not get the fiber ones to seal/seat properly, there was always a gap. I was also of the opinion that I wanted them to seal properly. The only test I could think of to confirm if they were sealing/seating properly was to blow through them and see if they "quacked." Holding a torch behind them and looking through for chinks of light worked too, but I prefered the "quack" test. I even wrecked a few reed blocks, by trying to "lap" in the rubber face, using some very fine wet and dry on a surface table  To get a "good" set of reeds I bought 4 brand new standard genuine yamaha petals, there about £10 each, and I kept buying reed cages off ebay, until I had a pair of reed blocks that "quacked" when I blew through them. I also learned not to use too strong a grade of loctite on the small M3 ? screws that secure the reed petals to the block, as I managed to shear a set of screws off, after trying to loosen them, after using too high grade of loctite. After weeks of buggering about, I got a good set, and I counted up everything it had cost me on fiber reed petals, standard reed petals, reed cages etc. I asked the very helpful people at Granby one day the price and availability of brand new standard reed block assemblies. Standard reed block assemblies are still available and are approx £100 pounds or so each, for what I spent fannyin about with mine, I could have bought brand new ones... steven. |
|
|
|
Post by neo on Aug 4, 2016 21:38:41 GMT 1
I bought the pair new as I thought it would save me a lot of faffing about 120 odd the pair well worth it my old ones were gaping at the tip where they meet the cage both top and bottom both sides it's like a different bike now literally night and day
|
|
|
|
Post by unrealedd on Aug 5, 2016 7:07:37 GMT 1
Thanks for posting your fix, may well help some one else out. Goes to show never take anything for granted.
Good result!
|
|
|
|
Post by neo on Aug 5, 2016 7:16:53 GMT 1
Thanks for posting your fix, may well help some one else out. Goes to show never take anything for granted. Good result! No problem were all on here to help each other my last rd (was a bitch) had exactly the same issue (never resolved) I swear it was the same thing as never checked the reeds |
|
|
|
Post by rigga on Aug 5, 2016 12:30:12 GMT 1
It can be many different things causing the rough running at that point in the rev range, mine wasn't the reeds, all bikes are different and whatever works for each, good find indeed though.
|
|
|
|
Post by neo on Aug 5, 2016 12:38:57 GMT 1
It can be many different things causing the rough running at that point in the rev range, mine wasn't the reeds, all bikes are different and whatever works for each, good find indeed though. Cheers rigga |
|
|
|
Post by Ozhammer on Aug 9, 2016 2:01:46 GMT 1
Just wanted to say that this thread really helped me sort out a similar hesitation issue at 5-6k on my freshly restored 4L0 (well it's actually a 5E0 but same same).
Dropping the needle one notch to second from top and turning the air screws out to 1 1/2 turns has all but cleared up the issue of hesitation and the engine now pulls cleanly right through the rev range, without me having to spend a cent - awesome. 
I just wish all forums were as useful as this one, so keep up the good work guys!
Rgds Ozhammer |
|
