renegade master Posted April 12, 2014 Report Share Posted April 12, 2014 Hi Guys, My 03 gas gas 280 txt is cutting out when the choke is pushed in.... it will only start again with full choke and some throttle! then it revs up a good bit, but when the choke is pushed back in again it starts spluttring and then wont idle and die! anyone have any ideas as to trying to fix? I messed about with the two screws on the side of the carb to see if it would make a difference but it didnt..... Cheers all. Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 12, 2014 Report Share Posted April 12, 2014 It sounds like your idle jets may be plugged. Time to pull the carb apart and give it a thorough cleaning. Be sure to write down the position of your idle and air screws before you tear it apart. Quote Link to comment Share on other sites More sharing options...
renegade master Posted April 12, 2014 Author Report Share Posted April 12, 2014 Cheers for that!.......Tis up and runnung again, but I suspect there something else going on behind the scenes because theres black oil/petrol dripping out from the exhaust manifold and the bike is running very smokey, now another thing is its using alot of gearbox oil but this could be draining from the front gear cog as maybe a seal has been worn out but I am not sure tho....... Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 13, 2014 Report Share Posted April 13, 2014 Is the bike leaking gearbox oil or is it burning it through the cylinder? If it is not leaking, it sounds like the clutch side crank seal is shot. This will allow the engine to suck the oil in and burn it through the cylinder. This would make for a very smoky pipe and eventually lots of black spooge coming out of the end of the silencer. If you are going to ride it as is, until you can get it fixed, make sure that you do not run the gearbox dry. Bad things (expensive too) happen when there is no lube. 1 Quote Link to comment Share on other sites More sharing options...
renegade master Posted April 14, 2014 Author Report Share Posted April 14, 2014 Thanks Five!, I think its leaking a bit of gearbox oil from the front sprocket! must be a seal in behind there some where that might be worn but I would say its a engine overhaul needed to get at that...... but now that you said about the engine sucking up the gearbox oil and making the bike more smokey. that would account for my suspicions of something going on behind the scenes! as it is running smokey and black spooge comming from the mainfold pipe, which crank seal do you mean? is it the simple clutch casing side one (eazy to replace) or the middle of the engine one (where I have to take the head off and engine out from the bike frame)? Cheers Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 14, 2014 Report Share Posted April 14, 2014 First, I want to say I am not an expert on the PRO engine so exact details of how that engine disassembly/reassembly should be confirmed elsewhere. Don't assume you need a rebuild. You might but there could be explanations that are easier to fix. For the spooge, are you fouling spark plugs frequently? it could be just running a little too much premix oil. Most people run between 80:1 and 100:1 ratio. Also, trials does tend to run the engines at low RPMS which does allow any excess oil to collect in the pipe. I would recommend cleaning out and repacking your silencer with new packing. It is not uncommon for a lot of smoke after climbing long hills as that heats the exhaust system and burns off some of the collected oil. *** Yes there is a seal on the shifter shaft that could be the source of your external leak. I would recommend doing a thorough cleaning of the outside of the engine, then starting the bike on the side stand and looking for the leak. Removing the skid pan (sump guard in UK, I think) will allow better viewing. The reason is that oil will run downhill and drip from the lowest part, so it could be leaking elsewhere and dripping off the shifter seal area. This seal may be changeable from the outside after removing the shift pedal. I know it was externally replaceable on the pre-PRO engines. *** The other seal I am referring to is the crankshaft seal on the clutch side (right). I know that to get near enough to see the seal, you have to remove the right side cover and gasket, then disassemble the clutch and remove the clutch basket from the crankshaft. I think you can replace the clutch side seal without splitting the cases but am not an expert on this. I just happened to be on the GasGasUSA web site earlier and noticed in the "tech" tab there is a link to a youtube video titles "Changing older Pro crank seals to the newer (o4+) style" so there may be an upgraded seal available if you need to replace it. Unfortunately, the Youtube videos are not working at the moment. I think it is a temporary problem. *** There is a similar crankshaft seal on the stator side as well, but there is no oil outside the seal (or should not be!). When the stator side seal fails, it allows extra air in making the bike run very lean. *** Hopefully some with better PRO knowledge can give you more precise info. Good luck and let us know how it works out. Quote Link to comment Share on other sites More sharing options...
biffsgasgas Posted April 22, 2014 Report Share Posted April 22, 2014 Thanks Five!, I think its leaking a bit of gearbox oil from the front sprocket! must be a seal in behind there some where that might be worn but I would say its a engine overhaul needed to get at that...... but now that you said about the engine sucking up the gearbox oil and making the bike more smokey. that would account for my suspicions of something going on behind the scenes! as it is running smokey and black spooge comming from the mainfold pipe, which crank seal do you mean? is it the simple clutch casing side one (eazy to replace) or the middle of the engine one (where I have to take the head off and engine out from the bike frame)? Cheers Consider this. If the crank case seals are faulted it could cause oil to be sucked in at low rpm (high vacuum) and oil to be pushed out at high rpm (high pressure). It could also be two unrelated issues. Thats_a_five has an idea. Lets test to see which it is. There is a vent at the top of the engine case above the transmission. That vent should be free and able to let the hot oil in the transmission to expand. With a cold engine it should allow that to breathe in outside air as well. In 2003 they built both the pro and older TXT models. The pro had the vent on the side by the sprocket and the TXT had it on the top right past the carb. If you really want to determine if pressure is bleeding over from the clutch side seal regardless of which bike you can put a pressure/vacuum gauge on the vent then start the bike. You should only see pressure build after the bike has been running till hot (fan running would be a good estimate). If you start the bike and the pressure builds or vacuum is gained within seconds of the engine running then you have a "clutch side" crank seal leaking. Just a final thought. You have been running this thing under choke for quite some time durring your test. Oil and smoke could be from all of that unburnt fuel in the exhaust. The sprocket seal leak could also be due to the bike being over 10 years old. --Biff 1 Quote Link to comment Share on other sites More sharing options...
renegade master Posted April 25, 2014 Author Report Share Posted April 25, 2014 Ok Thanks for all your detailed replies@ (thats_a_five)+(biffsgasgas) ok I will try the test, can you be more pacific as to what vac guage I need? cheers Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 28, 2014 Report Share Posted April 28, 2014 (edited) I had not thought of using a vacuum gage like Biff suggested. Brilliant idea! I think any automotive test type vacuum gage will work fine. Here is an example. ( know its in USA, just an illustration) http://www.ebay.com/itm/2-Dry-Utility-Vacuum-Pressure-Gauge-Blk-Steel-1-4-NPT-Lower-Mount-30HG-0PSI-/121304699145?pt=LH_DefaultDomain_0&hash=item1c3e52d109 I prefer vacuum gages that show plus and minus of -0- pressure (pressure and vacuum). Check with some of your buddies (mates in UK?), many guys who work on cars or bikes have one that get used once in a while. Probably let you borrow it for a pint. Edited April 28, 2014 by thats_a_five Quote Link to comment Share on other sites More sharing options...
renegade master Posted August 2, 2014 Author Report Share Posted August 2, 2014 Back again!, I decided on runing the bike tll winter and then worry about the gearbox oil problem..... but I didnt quite get that far..... frist of all the gear box oil is leaking out from the front sprocket shaft! and second the bike was very smokey! after every ride I had to put in gearbox oil (450ml) untill the last day when something eles happend which might be a new problem....... steem came from the cylinder head gasket!..... oops... so now its time to tear the bike apart!... on engine removal and strip down I think I found the main offender of disappearing gearbox oil, ....the crank case gasket was shot!..... and there was all gearbox oil in around the piston and con rod...... This still does'nt explain why the cylinder head gasket blow out! maybe the water pump packed in? I did notice that prior to this she was using alot of water??..... anyway she s all strpped down now on my work bench awaitng parts! This was the norm! leaking gearbox oil into the head........environmentally friendly or what! Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted August 3, 2014 Report Share Posted August 3, 2014 Yeah, that's more smoke than it should be making. Steam is a result of overheating. Could be due to bad water pump, pump seal, low coolant, and extreme lean running. While you have it apart, I would do all the seals, bearings, water pump (shaft and impellor), any gaskets that are not in really good condition. I hate to get it all together and still have a problem because I tried to save a dollar or two. Make sure you check the squish height on reassembly. Quote Link to comment Share on other sites More sharing options...
renegade master Posted August 3, 2014 Author Report Share Posted August 3, 2014 Thats_a_five, funny you should say that, when we had stripped the engine my mate spotted a (something) in the water pump kinda like a washer or some thing similar and its between the paddles..... only thing is I havent been able to take the water pump a part yet its proven to be a little bit tricky, but when I turn/spin it around its not as free as I would have thought it to have been? plus it makes a small scratching noise? ps whats the the squish height? Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted August 4, 2014 Report Share Posted August 4, 2014 There really should not be things floating around in the cooling system. And the water pump should not be "scratchy." There is a bearing and seal on the pump shaft. If something foreign gets into the pump, it will not circulate as it should - result overheated engine and steam. I would be taking a very close look at that piece of material in the pump vanes to try to figure out where it might have come from. Since you have the motor torn down, do a thorough flush of the cooling passages. I would pull the radiator too and give it a good flush in both directions and collect the water to search for other pieces of loose material. Squish height is the distance between the top of the piston to the head when assembled. After assembly, you put something like soft electrical solder through the plug hole, and turn the engine over by hand. When the piston come up it will "squish" the solder. move the piston down, them remove the solder and measure it's thickness. There are specifications for what that measurement should be. Too little space between the head and piston will give higher horsepower but make it very hard to kick start (high compression). Too much space will give lower horsepower but be easier to start (lower compression). High compression also requires higher octane fuel to prevent pinging (pinking in UK). On the older TXT, the adjustment for squish height was to use different thickness gaskets at the cylinder base. Kind of a pain in the @ss but only done at rebuild. Some of the newer bikes have changeable compression inserts in the head so squish may be set differently. Quote Link to comment Share on other sites More sharing options...
petert Posted August 5, 2014 Report Share Posted August 5, 2014 If it's a Pro I bet that washer is the one that sits between the brass bleed screw and the impeller. 1 Quote Link to comment Share on other sites More sharing options...
renegade master Posted August 6, 2014 Author Report Share Posted August 6, 2014 There really should not be things floating around in the cooling system. And the water pump should not be "scratchy." There is a bearing and seal on the pump shaft. If something foreign gets into the pump, it will not circulate as it should - result overheated engine and steam. I would be taking a very close look at that piece of material in the pump vanes to try to figure out where it might have come from. Since you have the motor torn down, do a thorough flush of the cooling passages. I would pull the radiator too and give it a good flush in both directions and collect the water to search for other pieces of loose material. Squish height is the distance between the top of the piston to the head when assembled. After assembly, you put something like soft electrical solder through the plug hole, and turn the engine over by hand. When the piston come up it will "squish" the solder. move the piston down, them remove the solder and measure it's thickness. There are specifications for what that measurement should be. Too little space between the head and piston will give higher horsepower but make it very hard to kick start (high compression). Too much space will give lower horsepower but be easier to start (lower compression). High compression also requires higher octane fuel to prevent pinging (pinking in UK). On the older TXT, the adjustment for squish height was to use different thickness gaskets at the cylinder base. Kind of a pain in the @ss but only done at rebuild. Some of the newer bikes have changeable compression inserts in the head so squish may be set differently. Ok i will check out the rad! see what else comes out....... good thinking As for the squish hight! thats way too technical for me! ..... frist of all do you mean when bike is fully reassembled cylender head back on and tightened up, you put a solder wire down the spark plug hole? I take it that you put a hook or turn the end of the solder so that the pistion will catch it? himm wait a min, will the pistion reach the solder at all? i am confused! (which is eazey to do) I always thought that the pistion doesn't come in contact with the bottom of the spark plug.......? I had the head off before and I re-used the bottom head gasket again and it started the same as before (3 kicks s always) and i have the 1mm head spacer on the bike too! but this time I will be using new gaskets so there will be a difference in squish hight then Quote Link to comment Share on other sites More sharing options...
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