Hi all. My engine is misfiring on tick over on No 3 cylinder, 1641. changed the lead. Changed the plug. it fires as soon as the revs pick up to above 1100 rpm. I am confused. Edit. also has elec ignition.
Well... It's possible the cam duration is causing some valve overlap. This means some exhaust puffs back up the inlet and because the ICT's have short manifolds, sucks back down into the next cylinder and kills the charge. I had same problem with a C35 cam which I believe is similar to the engle 110. After 2000 miles I had the engine to bits and there was noticable wear in the bores and on the pistons - bore wash due to the unburnt fuel. At speed it was fine, at tickover I reckon it ran on two cylinders. It ended up with a milder cam and will get ratio rockers to compensate for the less valve opening. This will overcome the duration problem hopefully. I could have put dells on and kinda wish I had, but not got the cash. Either don't worry, change the cam for a milder one or change the carbs for ones with longer manifolds. Or it could be something else - carby stuff isn't my favourite subject...
interesting. i had it rollong roaded and jetted. so it should be fine. what jet sizes should a 1641 have with ICT's
jetting i dont know, if you search for it on the other site you posted on laurie pettit usually gives the specs
done a compression test. No1 117 No2 118 No3 105 No 4 115 Is this drop on No 3 enough to stop it firing?
Did you try squirting a little bit of oil in the bore to see if the reading on 3 came up? If you do that and it stays low still, it could point to a problem with how one of the valves are seating I will try that next. Thanks Paul.
One thing i have noticed is that the idle mixture screw of the LH carb is so far out it is almost on the last turns of the thread. The RH carb is not the same. does this point to anything?
Yes. it stalls as No 4 cuts out as well. does this mean that it is over fuelling? and to rectify this the idle mix screw needs to be right out?
Cheers for the help Mungo. I thought that before but tried the old carb cleaner trick with no result. i think i am going to take the cab off and fit a new gasket. Hope I can do this with the engine in the bay. i have a pair of the Empi base gaskets below. http://www.dellorto.co.uk/merchandise/products_details.asp?PartNo=T1GASKET&CategoryID=12&PartsectionID=128
