old ozzie Posted December 13, 2013 Report Share Posted December 13, 2013 I recently bought a 2008 4T 320, wanted to try the 4 stroke thing. The bike starts very easily cold but is a mongrel when hot. Appears to be a fuel problem, the only way I have found to start it hot is 1 or 2 soft kicks with the throttle open a little, then after a few normal kicks it will fire a couple of times then start. Have had a couple of 4 stroke rider mates try to start it but with no better results. Spoke to a dealer who suggested the fuel line was to close to the cylinder and the fuel was getting hot and vaporizing, I rerouted the fuel line with no improvement. Any ideas? Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 13, 2013 Report Share Posted December 13, 2013 (edited) Just a thought. I see several people in the Montesa forum indicating hard, hot starting on 4RT's that were solved by proper valve adjustment. Might be worth checking your valve clearance? Good luck. Edited December 13, 2013 by thats_a_five Quote Link to comment Share on other sites More sharing options...
cleanorbust Posted December 13, 2013 Report Share Posted December 13, 2013 A well known problem on the 320 I believe. Advice has been to kick it over gently rather than using a strong swing on the kickstarter, use zero throttle when kicking it over (do not even touch the grip to avoid any instinct to twist it). Lowering float height may help. I think there was a hot starting kit done for them at the time. Malcolm Rathmell Sport may be able to advise on this via their website. Or just go back to a 2T. Quote Link to comment Share on other sites More sharing options...
huski Posted December 14, 2013 Report Share Posted December 14, 2013 They were sods to start when hot from new,made worse if the valve clearances have closed up.If you want a 4t,the Mont is better in all respects Quote Link to comment Share on other sites More sharing options...
copemech Posted December 15, 2013 Report Share Posted December 15, 2013 I cannot recall the year now, but the one I rode with the SPS carb restarted easily with a gentle(decompressor) prod when hot, and NO THROTTLE! Noew all that may go to hell if toy rip it over and flood the bike, good luck with that, same with most 4T stuff. Quote Link to comment Share on other sites More sharing options...
climber Posted December 15, 2013 Report Share Posted December 15, 2013 Hey down under. I have a 320F my self and I would have tried to adjust the airmix screw. As you do 1-2 soft kicks first when warm and then it starts after 2 or 3 new kicks it seems to me that you give it a little more air under the 1-2 soft first atempts, when you do open up the gas a little. Perhaps it gets a little to much throught the pilot circuit. The pilot airmix screw is placed at the carburators end towards the airfilter. Try to turn this screw 1/4 turn anti-clockwise. This screw should normally be 1 full turn out from bottom position. Try this airmix screw 3/4 turn from bottom, 1 turn from bottom and 1 1/4 turn from bottom if the first advice didn´t help. As it runs normally from cold this I guess is a minior problem to fix. These bikes have character. Threat it nice. Good luck. Quote Link to comment Share on other sites More sharing options...
sirhc Posted December 16, 2013 Report Share Posted December 16, 2013 I've had several 3.2's and I really liked them! Once set up correctly you shouldn't have a problem starting it. If yours has the SPS carb I found the best jetting to be a 42 pilot with a 128 main jet from a dellorto carb. Air screw 1/4 to 3/4 out. The air screw really depends on the bike. Some wanted it turned out a little more, some a little less. The balance between the air screw setting and the idle screw setting is what seemed to really affect starting. Don't have the idle too low. These bikes are not like the Beta or Montesa 4t's where you push the kickstart through, you have to give them a good manly kick! And also not stab at it like a 2t. My bikes always worked best on hot days. The motor seemed a little looser, revved quicker and started easier. Sorry I didn't write down jetting for the none SPS carb, but same things apply. Also the obvious thing is make sure the carb is very clean! Quote Link to comment Share on other sites More sharing options...
old ozzie Posted December 20, 2013 Author Report Share Posted December 20, 2013 Thanks for the advice and info guys, I am having a week or so off work over xmas so will try as many of the suggestions as I can and see if we can get the old girl sorted out. Quote Link to comment Share on other sites More sharing options...
old ozzie Posted December 22, 2013 Author Report Share Posted December 22, 2013 I have checked the valve clearance, isn't it fun working out how to get the tappet cover off for the first time lol. Inlet was nearly 0.15, exhaust was out to nearly 0.35. The exhaust is loose I know, but better than binding up. Will start looking at other suggestions now. Quote Link to comment Share on other sites More sharing options...
electric steve Posted January 6, 2014 Report Share Posted January 6, 2014 Like the 1st Sherco 4t that ran the Dellorto they ran horrendously rich, main problem was the needle straight was too thin this could also be the problem with the present carb, the needle straight has a big bearing on mixture on start up. Steve. Quote Link to comment Share on other sites More sharing options...
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