Prodigy Posted February 28, 2010 Share Posted February 28, 2010 Hi folks, looking for some ideas on what the problem might be with my thundercat. The problem is intermittent and shows itself several ways, or perhaps there is more than one problem. Firstly after a steady cruise at 80mph on the motorway, when I come off the motorway the engine seems to stutter and give less output. Also there is a situation when idling that the revs seem to go up about 1000rpm and then sometimes settles again, this happens with the throttle fully closed. Looking forward to hearing peoples theories. Cheers Link to comment Share on other sites More sharing options...
pilninggas Posted February 28, 2010 Share Posted February 28, 2010 probably worn-jets/needles. could also be valve clearances. Link to comment Share on other sites More sharing options...
Rich_B Posted February 28, 2010 Share Posted February 28, 2010 After a motorway cruise what does your temp gauge say? Mine gets like yours unless I block off radiator with a bit of plywood! Link to comment Share on other sites More sharing options...
Prodigy Posted February 28, 2010 Author Share Posted February 28, 2010 After a motorway cruise what does your temp gauge say? Mine gets like yours unless I block off radiator with a bit of plywood! Temp gauge barely moves on it. Would you expect worn jets on a bike with 20k on the clock? Valve clearances easy enough to check? Cheers Link to comment Share on other sites More sharing options...
pilninggas Posted February 28, 2010 Share Posted February 28, 2010 Temp gauge barely moves on it. Would you expect worn jets on a bike with 20k on the clock? Valve clearances easy enough to check? Cheers the jets may well be worn at that sort of mileage - they go oval as the needle vibrates in the orifice (ooh 'er missus) and ovals the hole making the bike run rich. Not done the vlaves on a 'cat, but have done em on an exup...usual stuff its the time-hassle of getting to them thats the biggest problem. of course you could sort both these things and not solve the problem. You might just have to investigate both. For jets/needles google a company called allens. Link to comment Share on other sites More sharing options...
Rich_B Posted March 1, 2010 Share Posted March 1, 2010 Your bike sounds exactly like mine. . . Mine has new thermostat and coolant which didn't make a blind bit of difference. My mechanic brother doing my shims as we speak! They're a royal pain if your have no patience. . . like me. I didn't put new plugs in cos I thought they looked ok but now I'm gonna get new plugs and jets to see if that helps matters, Thanks Pilningas Link to comment Share on other sites More sharing options...
Prodigy Posted March 1, 2010 Author Share Posted March 1, 2010 Your bike sounds exactly like mine. . . Mine has new thermostat and coolant which didn't make a blind bit of difference. My mechanic brother doing my shims as we speak! They're a royal pain if your have no patience. . . like me. I didn't put new plugs in cos I thought they looked ok but now I'm gonna get new plugs and jets to see if that helps matters, Thanks Pilningas Let me know if you find a good deal on jet kit for the bike, I'd be interested to know. cheers Link to comment Share on other sites More sharing options...
Rich_B Posted March 2, 2010 Share Posted March 2, 2010 It'll be a while, but I'll post here asap Link to comment Share on other sites More sharing options...
Prodigy Posted March 2, 2010 Author Share Posted March 2, 2010 It'll be a while, but I'll post here asap No worries, I'm doing some reasearch and I'll let you know if I find anything. I've not got time or money to address this issue right away. Link to comment Share on other sites More sharing options...
Prodigy Posted March 5, 2010 Author Share Posted March 5, 2010 OK, so Allens got back to me and asked me for part numbers of the jets and needles. How easy/difficult is it going to be to get this information? Are the jets and needles a standard fittment for bike and year? If so can anyone point me in the right direction for the info I need to give to Allens. This is the info they requested: "If you could advise the codes from the needles (located around the top, where the e-clip fits) and also the needles jets (3 digit number, then a letter then a number)" Cheers Link to comment Share on other sites More sharing options...
Rich_B Posted March 6, 2010 Share Posted March 6, 2010 You have to take carbs off and take em to bits to look at the jets and needles, which may have been changed from standard to suit an aftermarket exhaust system! Link to comment Share on other sites More sharing options...
Prodigy Posted March 7, 2010 Author Share Posted March 7, 2010 You have to take carbs off and take em to bits to look at the jets and needles, which may have been changed from standard to suit an aftermarket exhaust system! OK, having never taken the carbs off this bike, how long of a job is it likely to be? Cheers Link to comment Share on other sites More sharing options...
Rich_B Posted March 8, 2010 Share Posted March 8, 2010 If I was you I'd get a haynes manual and budget for spending at least a day taking carbs off and to bits and then back together again if you use the bike as your only transport. Link to comment Share on other sites More sharing options...
Prodigy Posted March 8, 2010 Author Share Posted March 8, 2010 If I was you I'd get a haynes manual and budget for spending at least a day taking carbs off and to bits and then back together again if you use the bike as your only transport. It can wait until I have the VN800 taxed then I have plenty of time! Link to comment Share on other sites More sharing options...
Rich_B Posted March 10, 2010 Share Posted March 10, 2010 The latest idea is that the oil cooler might cooling the whole sytem too much. . . Link to comment Share on other sites More sharing options...
Prodigy Posted March 17, 2010 Author Share Posted March 17, 2010 The latest idea is that the oil cooler might cooling the whole sytem too much. . . I thought being water cooled the bike didnt have an oil cooler? Link to comment Share on other sites More sharing options...
Rich_B Posted March 18, 2010 Share Posted March 18, 2010 I thought being water cooled the bike didnt have an oil cooler? bit o both. Well a lot of water cooling n a bit of oil. Link to comment Share on other sites More sharing options...
Prodigy Posted March 18, 2010 Author Share Posted March 18, 2010 bit o both. Well a lot of water cooling n a bit of oil. Do we know what the temp guage should rise to on a normal ride? Mine lifts a bit off the bottom but not much. Link to comment Share on other sites More sharing options...
Rich_B Posted March 20, 2010 Share Posted March 20, 2010 Do we know what the temp guage should rise to on a normal ride? Mine lifts a bit off the bottom but not much. Nope! I've never seen mine move - other than stood in traffic on a very hot day, then it went to 100 and fan came on. This is only a distant memory though, it's been 3 months since I saw my bike let alone swung a leg over it. Waiting for a new clutch to arrive, now. Shims were ok so not all bad news from my mechanic type brother. Link to comment Share on other sites More sharing options...
Prodigy Posted March 22, 2010 Author Share Posted March 22, 2010 Nope! I've never seen mine move - other than stood in traffic on a very hot day, then it went to 100 and fan came on. This is only a distant memory though, it's been 3 months since I saw my bike let alone swung a leg over it. Waiting for a new clutch to arrive, now. Shims were ok so not all bad news from my mechanic type brother. So your valve clearences checked out OK? What mileage is your bike? To top all this I think my original downpipes have given up, bike is more noisey than usual, sounds like exhaust, have stainless micron can so I'm going with downpipes, will investigate and report. Link to comment Share on other sites More sharing options...
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