nastyroxinc Posted May 15, 2012 Report Share Posted May 15, 2012 Good afternoon all. As some of you may have seen from previous posts, I have recently bought the above bike. It was bought as a “non-runner” (at a matching price) on account of the fact that the vendor couldn’t get it started and running for more than a few seconds. Obviously this is the first problem I need to solve, and I’m looking for any hints / tips anyone may have.... Time and resource is limited as I live in Munich and the bike is currently in the UK, I want to get it running properly before bringing it over here and have around two days to do so.... The bike hasn’t really been used for a year, kicks over eventually and fires, then dies after a couple of seconds – It sounds like it’s bogging full of fuel, likewise, when you touch the throttle it dies instantly. It was running a couple of weeks ago but I only saw a video clip of it, rather than in person. Here are the steps I’m looking to take, please feel free to help me by offering more.. (Fuel is already drained out) Strip, clean and reassemble carb, replace any blocked jets as required. Check float level and condition. Decoke centre silencer. What is the easiest way to do this without cutting a hole in the back? Is caustic soda ok on this, if so, what’s the ratio to mix? Alternatively, I’ve heard brake cleaner may also be an option? Check reeds – I’m new to older 2T maintenance – What do I need to look for? Stator – I’ve heard these can be an issue. What is the resistance rating and across which points? Compression check – Again, ideal measurements would be helpful here... Other than that, it needs a fork seal which I can handle... Thanks in advance... Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted May 16, 2012 Report Share Posted May 16, 2012 It sounds like a fuel issue to me. Try kicking it a few times then pull the spark plug. If it is dry a thorough cleaning and blowing through all the passages in the carb (especially the choke and main jets) should do the job. If it is wet, clean the plug, remove the air filter, kick it to clear the jug and bottom end out, reinstall the plug and try again. It may be as simple as a plugged air filter. Replace the plug even if it looks good. De-coking the exhaust will not make it start better unless it is clogged to the point where it cannot breathe at all (unlikely). There are other threads with onfo about ways to do this. Let us know what you find. Quote Link to comment Share on other sites More sharing options...
nastyroxinc Posted May 17, 2012 Author Report Share Posted May 17, 2012 Thanks for the tips. Also just realised that spark plug(s) weren't on my shopping list! Bike and I will be reunited next weekend hopefully, so will let you know the progress.... Quote Link to comment Share on other sites More sharing options...
copemech Posted May 18, 2012 Report Share Posted May 18, 2012 Clean the carby and blow out the jets, frehs plug and fuel. Yhat will get you a long way! Quote Link to comment Share on other sites More sharing options...
nastyroxinc Posted May 18, 2012 Author Report Share Posted May 18, 2012 Thanks guys. Anyone know the correct plug type and gap? Quote Link to comment Share on other sites More sharing options...
stonezone Posted May 21, 2012 Report Share Posted May 21, 2012 also, change all the hoses on the carb! a buddy got a non-working bike the same way and that was the fix... Quote Link to comment Share on other sites More sharing options...
jse Posted May 21, 2012 Report Share Posted May 21, 2012 Thanks guys. Anyone know the correct plug type and gap? NGK BPR5ES, or better, an NGK BPR5EIX set to .6mm Jon Quote Link to comment Share on other sites More sharing options...
nastyroxinc Posted May 26, 2012 Author Report Share Posted May 26, 2012 Ok, a little more help required please.... Carb cleaned, fresh fuel in (66:1 ratio) and new plug fitted. Air filter cleaned and all hoses blown through. Bike started and ran for quite some time then just bogged and died. The only way I could get it to start and run again was on the choke, effectively using it as a makeshift throttle. Eventually it would ride again as normal on the throttle. At present I have the two screws on the side of the carb set as follows: Smaller one (nearest the front of the bike) 4 turns out. Larger one (closest to rear of bike) 3 1/2 turns out. Any ideas anyone? Thanks in advance (as always!) Quote Link to comment Share on other sites More sharing options...
laser1 Posted May 26, 2012 Report Share Posted May 26, 2012 Sounds like your suckin dirt into the carb and clogging the pilot. You can confirm this by pulling the pilot jet and looking through it. You may want to make sure the back side of the air box hose is properly seated on the carb donut and maybe switch to a new air filter. Also - check that the throttle slide cover is seated to the carb body and not cracked. Quote Link to comment Share on other sites More sharing options...
jse Posted May 26, 2012 Report Share Posted May 26, 2012 Sounds like your suckin dirt into the carb and clogging the pilot. You can confirm this by pulling the pilot jet and looking through it. You may want to make sure the back side of the air box hose is properly seated on the carb donut and maybe switch to a new air filter. Also - check that the throttle slide cover is seated to the carb body and not cracked. Just to follow the process of elimination, check for fuel flow at the petcock (actually, it would be good to take it out and make sure the filters are clean) and be sure the vent is installed the proper way. There is an o-ring in the carb cap, check to be sure it was not lost. You might want to take the manifold off and check to be sure the reed tips are not broken or frayed. Quote Link to comment Share on other sites More sharing options...
nastyroxinc Posted May 27, 2012 Author Report Share Posted May 27, 2012 Vent in breather hose was in the wrong way round!? I've put this right, and the issue seems to have gone away.... Now this is sorted, any tips on how to set the idle correctly? I'm not familiar with his carb at all..... This is the first time I've owned a trials bike, and at present all I can get it to do is either pull me round slow manoeuvres way too quickly or stall! The Montesa 315 I rode the other week was great as it would just chug along in slower manoeuvres with no throttle at all, but at a really slow pace... Is the same achievable with my bike or is the 125cc engine way too small for this? Thanks again, Quote Link to comment Share on other sites More sharing options...
jse Posted May 27, 2012 Report Share Posted May 27, 2012 Vent in breather hose was in the wrong way round!? I've put this right, and the issue seems to have gone away.... Now this is sorted, any tips on how to set the idle correctly? I'm not familiar with his carb at all..... This is the first time I've owned a trials bike, and at present all I can get it to do is either pull me round slow manoeuvres way too quickly or stall! The Montesa 315 I rode the other week was great as it would just chug along in slower manoeuvres with no throttle at all, but at a really slow pace... Is the same achievable with my bike or is the 125cc engine way too small for this? Thanks again, The 315 engine was double the size of your bike (with the related moving internal mass), so it's not necessarily a direct comparison but you might consider lowering your gearing a little more to fit your present riding style. To set idle: 1) engine in neutral and warmed up, quickly "blip" the throttle on/off from idle and adjust the mixture screw (it's the one closest to the manifold, on your left as you look at the carb) in and/or out to get the best off-idle throttle response with no "bogging". 2) engine in 1st gear and warm, with the clutch lever pulled back normally (usually with one finger and back to the knuckles) adjust the idle speed screw (the screw in the "center" of the carb body, to the right of the mixture screw) to to get a reasonable idle speed. You may want to adjust the idle speed up/down later, based on experience, but this will get you started. Jon Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.