Mohawk Posted June 10, 2023 Report Share Posted June 10, 2023 If this had race plugs, was it a race bike. If yes did it ever have engine work ? Did someone do RC30 piston ring trick & remove one compression ring ? Crap for starting but fine on a race bike using a starting donkey. As others have said do a cold compression test & a leak down test. 3 1 Quote Link to comment Share on other sites More sharing options...
hollo Posted June 14, 2023 Author Report Share Posted June 14, 2023 On 6/10/2023 at 5:32 PM, Mohawk said: If this had race plugs, was it a race bike. If yes did it ever have engine work ? Did someone do RC30 piston ring trick & remove one compression ring ? Crap for starting but fine on a race bike using a starting donkey. As others have said do a cold compression test & a leak down test. I don't think it was a race bike , more like someones trackday toy . It only gave an average power output of 113hp at the rear wheel with the only mod being an end can fitted . I've then added the full exhaust ,airbox and power commander , so I'm pretty sure it was not tuned. I'll mention about the cold compression and leak down test when I hand it over to be fixed later in the year. Thanks for the suggestions Mike . 1 Quote Link to comment Share on other sites More sharing options...
hollo Posted October 20, 2023 Author Report Share Posted October 20, 2023 I have an update - it's fixed and will now start from cold, thanks to Jim from Superbike Surgery . The ECU was at fault , and I'll try to explain..... From stone cold the ECU was only firing the injectors the required longer firing time of 5 to 6m/s for only the first 4 revolutions so 2 power strokes of the crank , it then reverted to the warm running duration of opening the injectors of only approx 2m/s . So there was never enough fuel to fire it into life from cold . All the resistance readings from the coolant sensor are correct , and change with temp , but the ECU is ignoring this input . If a much larger resistance is added, the ECU actually sees this massive increase in resistance and will fire the injectors for the required 5 to 6m/s , so the bike will start from cold - Yay . However just to make things difficult the ECU then does not recognise the natural fall in resistance from the coolant sensor when the engine warms up , so stays at the longer injector values . The only way to get the injectors back to firing the warm duration of 2 to 3m/s is to turn the bike off and restart it . Hopefully this is clear. Jim's has made a fix for me, so I can add resistance and I'm now able to start it from cold ,but I plan to get another ECU as a permanent fix . I think he's made a few youtube videos of the whole process ,which should be out in the near future. Mike . 9 6 Quote Link to comment Share on other sites More sharing options...
2moto Posted October 20, 2023 Report Share Posted October 20, 2023 It's very rare these days that ECUs fail. They are now probably the most reliable part of the system. Glad you got it sorted. 2 1 Quote Link to comment Share on other sites More sharing options...
TLRS Posted October 20, 2023 Report Share Posted October 20, 2023 1 hour ago, hollo said: I have an update - it's fixed and will now start from cold, thanks to Jim from Superbike Surgery . The ECU was at fault , and I'll try to explain..... From stone cold the ECU was only firing the injectors the required longer firing time of 5 to 6m/s for only the first 4 revolutions so 2 power strokes of the crank , it then reverted to the warm running duration of opening the injectors of only approx 2m/s . So there was never enough fuel to fire it into life from cold . All the resistance readings from the coolant sensor are correct , and change with temp , but the ECU is ignoring this input . If a much larger resistance is added, the ECU actually sees this massive increase in resistance and will fire the injectors for the required 5 to 6m/s , so the bike will start from cold - Yay . However just to make things difficult the ECU then does not recognise the natural fall in resistance from the coolant sensor when the engine warms up , so stays at the longer injector values . The only way to get the injectors back to firing the warm duration of 2 to 3m/s is to turn the bike off and restart it . Hopefully this is clear. Jim's has made a fix for me, so I can add resistance and I'm now able to start it from cold ,but I plan to get another ECU as a permanent fix . I think he's made a few youtube videos of the whole process ,which should be out in the near future. Mike . Sounds like some proper detective work. So.. it's the ecu not responding correctly to the temp sensor? The sensor was checked, wasn't it? Quote Link to comment Share on other sites More sharing options...
hollo Posted October 20, 2023 Author Report Share Posted October 20, 2023 3 hours ago, TLRS said: Sounds like some proper detective work. So.. it's the ecu not responding correctly to the temp sensor? The sensor was checked, wasn't it? Yep , all the outputs from the temp sender were measured and were all in spec as per the manual . As the fault can be replicated we are both 99.99% sure it's the ECU . Just me being me , and want to be 100% sure I plan to get a second hand ECU ( as new ones are no longer available and were price at about £3200 ) and get Jim to run the same tests of injector duration V's coolant sender resistance just to be sure . This won't be for a good few months as I'm just about the put the bike away for the winter and need to save a few quid to buy a second hand ECU. 2 Quote Link to comment Share on other sites More sharing options...
TLRS Posted October 21, 2023 Report Share Posted October 21, 2023 2 hours ago, hollo said: Yep , all the outputs from the temp sender were measured and were all in spec as per the manual . As the fault can be replicated we are both 99.99% sure it's the ECU . Just me being me , and want to be 100% sure I plan to get a second hand ECU ( as new ones are no longer available and were price at about £3200 ) and get Jim to run the same tests of injector duration V's coolant sender resistance just to be sure . This won't be for a good few months as I'm just about the put the bike away for the winter and need to save a few quid to buy a second hand ECU. There’s a guy, russian i think, who opened a tlr ecu. Had to remove a lot of gunk to get to the print. Yet managed to replace a part or resolder it or something. Long story short, maybe it can be fixed by a grown up? 1 1 Quote Link to comment Share on other sites More sharing options...
ssray Posted October 21, 2023 Report Share Posted October 21, 2023 6 hours ago, TLRS said: There’s a guy, russian i think, who opened a tlr ecu. Had to remove a lot of gunk to get to the print. Yet managed to replace a part or resolder it or something. Long story short, maybe it can be fixed by a grown up? I think they fill them with silicon 1 Quote Link to comment Share on other sites More sharing options...
426hemi Posted October 21, 2023 Report Share Posted October 21, 2023 15 minutes ago, ssray said: I think they fill them with silicon It’s a resin, most ecu’s have it to help with vibration and contamination, I’ve watched them being repaired and any good repairers will know where to dig into the ecu. 1 1 Quote Link to comment Share on other sites More sharing options...
hollo Posted October 21, 2023 Author Report Share Posted October 21, 2023 Yep , they are filled and sealed with something like silicon , so it's not possible to get to any of the workings . I've had a quick look , on tinternet but trying to find someone with experience or had worked on a bike specific ecu which is best part of 30 years old and Honda only made 500 is proving difficult . I'm open to suggestions if anyone can recommend anyone. Mike . Quote Link to comment Share on other sites More sharing options...
lesviffer 750 Posted October 21, 2023 Report Share Posted October 21, 2023 Theres a chap in Greece who repairs Honda NSR250 ecu's and i know several happy customers here in UK, His name i think from memory is, Nick Prionas he trades under 2stroke racelab, and use to advertise on fleabay under NSR250 spares. Might be useful, might not. 1 1 Quote Link to comment Share on other sites More sharing options...
ssray Posted October 22, 2023 Report Share Posted October 22, 2023 9 hours ago, lesviffer 750 said: Theres a chap in Greece who repairs Honda NSR250 ecu's and i know several happy customers here in UK, His name i think from memory is, Nick Prionas he trades under 2stroke racelab, and use to advertise on fleabay under NSR250 spares. Might be useful, might not. https://www.ebay.co.uk/itm/275346366702?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=66MdNhkXTo2&sssrc=4429486&ssuid=hNc7HZIaSC6&var=&widget_ver=artemis&media=COPY 1 Quote Link to comment Share on other sites More sharing options...
ssray Posted October 22, 2023 Report Share Posted October 22, 2023 Maybe worth a ask here too https://www.carmoelectronics.co.uk/index.php?main_page=product_free_shipping_info&products_id=1628 1 Quote Link to comment Share on other sites More sharing options...
hollo Posted yesterday at 02:58 PM Author Report Share Posted yesterday at 02:58 PM and update time...... If you've got this far , thanks. So , I managed to get my hands on another ECU , drum roll please........and the fucking thing is still the same - piss sticks and arse biscuits. I'm really at a loss now . So to re-cap, from stone cold the ECU was getting the correct resistance from the coolant sensor and the other sensors , but the injectors were not firing for long enough for a cold start. So this points to a faulty or non-existent cold start procedure in the ECU . Also as above for the 'fix' , if an in-line resistor is added the ECU and injectors can be fooled into giving the cold engine more fuel , again, it points to a faulty ECU . However, after great expense the new ECU makes no difference. So I'm now stumped and out of ideas. Ideally I'd like to try and do a swap of giving my ECU to someone with a 45 for them to try it , or me try their known good ECU , just to try and make sense of what's going on , but these bikes are a bit thin on ground. My 'fix' of the in-line resistor does work , buts it's a real balls ache to keep taking the seat off and on when you want to go for a ride ,and it still doesn't really fix the true route cause of the cold starting. He's a pic of happier times at last years CBT at Donington , where once warm it ran like clockwork. 3 Quote Link to comment Share on other sites More sharing options...
marvin Posted yesterday at 03:12 PM Report Share Posted yesterday at 03:12 PM 13 minutes ago, hollo said: and update time...... If you've got this far , thanks. So , I managed to get my hands on another ECU , drum roll please........and the fucking thing is still the same - piss sticks and arse biscuits. I'm really at a loss now . So to re-cap, from stone cold the ECU was getting the correct resistance from the coolant sensor and the other sensors , but the injectors were not firing for long enough for a cold start. So this points to a faulty or non-existent cold start procedure in the ECU . Also as above for the 'fix' , if an in-line resistor is added the ECU and injectors can be fooled into giving the cold engine more fuel , again, it points to a faulty ECU . However, after great expense the new ECU makes no difference. So I'm now stumped and out of ideas. Ideally I'd like to try and do a swap of giving my ECU to someone with a 45 for them to try it , or me try their known good ECU , just to try and make sense of what's going on , but these bikes are a bit thin on ground. My 'fix' of the in-line resistor does work , buts it's a real balls ache to keep taking the seat off and on when you want to go for a ride ,and it still doesn't really fix the true route cause of the cold starting. He's a pic of happier times at last years CBT at Donington , where once warm it ran like clockwork. Lovely looking bike. Shame it’s broken. Quote Link to comment Share on other sites More sharing options...
CMSMJ1 Posted yesterday at 05:43 PM Report Share Posted yesterday at 05:43 PM There's at least two other 45s on here, maybe three? Spike, rompy and scunnylad? Or the guru, Rick Oliver to does he know anyone? Quote Link to comment Share on other sites More sharing options...
TLRS Posted yesterday at 07:38 PM Report Share Posted yesterday at 07:38 PM @Stephenrc45? 1 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.