Jonny Posted March 7, 2020 Share Posted March 7, 2020 Hi there, This is the story: I had a problem with an inlet valve on my 1230 EFE. As it happened I had a spare head I took off a running bike, so I swapped the heads over. Both were standard. After rebuilding the bike, I tried to start it. It wouldn't run on cylinder number two, the other three fired fine. There doesn't seem to be any fuel getting into the chamber as when I check the plug it is dry. The spark seem fine. The float bowl fills up. Here a list of what I have done so far... Cleaned the plugs, changed the plugs, swapped the plug leads, swapped the coils, cleaned the carbs, swapped the pilot jets, swapped the carbs for a different set with different air filters, changed the manifolds, changed the vacuum hose, changed the fuel line, removed the throttle cable, checked the valve clearences, checked the compression (fine) run a leak down test (fine). What am I missing????? I'm totally stumped! Thanks Jonny Quote Link to comment
wraith Posted March 7, 2020 Share Posted March 7, 2020 When you turn the engine over, ever by hand or by the starter, are the valves opening/closing? Quote Link to comment
Jonny Posted March 7, 2020 Author Share Posted March 7, 2020 (edited) 12 hours ago, wraith said: When you turn the engine over, ever by hand or by the starter, are the valves opening/closing? I had not thought of this, although if it was stuck open wouldn't the leak down test reveal it? Edited March 8, 2020 by Jonny Quote Link to comment
Sheep Posted March 7, 2020 Share Posted March 7, 2020 When its running have you checked the downpipe on number two to see if its warm/hot??...I once had this issue,thought it was lack of fuel,but when I revved the motor the downpipe got hot..feckin hot lol...The mixture on the cylinder was fuelling incorrectly at idle but came good further up the range... Quote Link to comment
Jonny Posted March 7, 2020 Author Share Posted March 7, 2020 1 minute ago, Sheep said: When its running have you checked the downpipe on number two to see if its warm/hot??...I once had this issue,thought it was lack of fuel,but when I revved the motor the downpipe got hot..feckin hot lol...The mixture on the cylinder was fuelling incorrectly at idle but came good further up the range... The exhaust from cylinder two is stone cold. Quote Link to comment
BigT Posted March 9, 2020 Share Posted March 9, 2020 So, when you swapped the plug leads, the problem stayed at #2? The symptom you describe usually indicates a vacuum leak, you have the vacuum hose on the correct carb port? Quote Link to comment
Jonny Posted March 9, 2020 Author Share Posted March 9, 2020 7 hours ago, BigT said: So, when you swapped the plug leads, the problem stayed at #2? The symptom you describe usually indicates a vacuum leak, you have the vacuum hose on the correct carb port? Yes - that is correct. The vacuum hose is connected to the top of carb two on both sets of carbs. I have also tried with that outlet blocked off. I might have to try that again though... Thanks. Quote Link to comment
wraith Posted March 9, 2020 Share Posted March 9, 2020 Put a M6 bolt in the vacuum pipe and the tap on prime and see if it makes any difference. Washing up liquid is good to check for air leaks on the carbs/ manifold. 1 Quote Link to comment
bluedog59 Posted March 9, 2020 Share Posted March 9, 2020 Does No2 make any attempt to chime in when you rev it ? Could be a blocked pilot jet. Quote Link to comment
BigT Posted March 9, 2020 Share Posted March 9, 2020 Are you sure the pods are not blocking the idle air jet in the mouth of the carb? What brand pods are you trying? Quote Link to comment
Jonny Posted March 10, 2020 Author Share Posted March 10, 2020 On 3/9/2020 at 12:25 PM, wraith said: Put a M6 bolt in the vacuum pipe and the tap on prime and see if it makes any difference. Washing up liquid is good to check for air leaks on the carbs/ manifold. I’ll give that a go. Cheers! Quote Link to comment
Jonny Posted March 10, 2020 Author Share Posted March 10, 2020 (edited) 23 hours ago, BigT said: Are you sure the pods are not blocking the idle air jet in the mouth of the carb? What brand pods are you trying? K&N single pods on one set and K&N twin ovals on the other. I’ll look into that though! Thanks. Edited March 10, 2020 by Jonny Quote Link to comment
BigT Posted March 11, 2020 Share Posted March 11, 2020 K&N s generally don't have that issue Quote Link to comment
Jonny Posted March 11, 2020 Author Share Posted March 11, 2020 12 hours ago, BigT said: K&N s generally don't have that issue TBH anything is worth a go! Quote Link to comment
BigT Posted March 11, 2020 Share Posted March 11, 2020 Indeed, these types of maddening problems are generally one small thing Quote Link to comment
Jonny Posted March 14, 2020 Author Share Posted March 14, 2020 The bike is now fixed and running! Thanks for the help! I'm not entirely sure what the problem was I think it may have been a combination of things. Certianly, blocking the vacuum off and running on primary helped but only on one set of carbs, on the others it was no better, so I suspect the original carbs I tried have a separate issue. Anyway, now balance and running! 1 Quote Link to comment
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.