SteveHobart 57 Posted November 24, 2020 Hey guys. Still chasing a gremlin in the XF 250 Crossflow. So it’ll turn over and run for a very little while (like seconds) then lock up. At the moment I can rock it back and forth about 20mm on the Balancer with a breaker bar and that’s it. It’s not seized, but it’s definately stuck on something. Engine was professionally rebuilt, so I’m thinking it’s something I did. All I put on was the Flywheel, clutch, and pilot bearing. The rest was done by a pro. Engine is out at the moment, flywheel and clutch look ok. Mains and Conrod bearings look fine, no play in the rods or mains.For reference. Engine was professionally rebuilt with: - Aftermarket Cam - New Valve Springs and timing gear- 0 decked block- everything professionally machined and reassembled. I’m out of ideas....HELP! Sent from my iPhone using Tapatalk 1 bear351c reacted to this Share this post Link to post Share on other sites
dex 2,065 Posted November 24, 2020 Starter motor ,? try unbolting it and winding over by hand 1 Thom reacted to this Share this post Link to post Share on other sites
SteveHobart 57 Posted November 24, 2020 Thanks Mate. Should have added, started and plugs are out, still doesn’t turn.Sent from my iPhone using Tapatalk Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 24, 2020 Hey Steve, did you have it running properly at some stage? Or had it done this since you got it back?Sent from my S21 using Tapatalk Share this post Link to post Share on other sites
SteveHobart 57 Posted November 24, 2020 It’s done this since I got it back. Free up, lock up, free up etc etc Sent from my iPhone using Tapatalk 1 Outback Jack reacted to this Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 24, 2020 It’s done this since I got it back. Free up, lock up, free up etc etc Sent from my iPhone using TapatalkThere's something seriously wrong mate.Either the cam is seized or there is something like too long pushrods etc.Don't fark with it, take it to the muppets that rebuilt it and get them to fix it.If you mess with it too much you will void your warranty.Sent from my S21 using Tapatalk Share this post Link to post Share on other sites
SPArKy_Dave 8,871 Posted November 24, 2020 Could be stuck valves, valve-spring bind, or the cam is too big for zero deck, and now the lifters have pumped up, the valves are hitting the pistons. If you have a bore-scope, see if the piston crowns are marked/damaged. Or take the rockers off, then try turning the engine over by hand. 1 Outback Jack reacted to this Share this post Link to post Share on other sites
Thom 6,650 Posted November 24, 2020 Starter motor ,? try unbolting it and winding over by handI'd hedge my bets on the starter, if the drive is binding up on the flywheel it could cause the engine to lock up and winding it back and forward with the breaker bar is making it release Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 24, 2020 Starter is already off Thom.Whatever it is it's internal.Sent from my S21 using Tapatalk Share this post Link to post Share on other sites
bear351c 10,270 Posted November 25, 2020 Has it ever started and ran...?? 1 Outback Jack reacted to this Share this post Link to post Share on other sites
SteveHobart 57 Posted November 25, 2020 Not really Bear. Not for more than a minute before doing this. I’m trying to eliminate one thing at a time. Today is the bottom end. Just pulled one of the main caps and it still has bearing grease on it! So I’m assuming it’s not a bottom end thingSent from my iPhone using Tapatalk 1 Outback Jack reacted to this Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 25, 2020 Why aren't you just returning it to the 'professional' guys who built it?Seems silly to be pulling apart a motor that's under warranty.Sent from my S21 using Tapatalk 1 Slow250XC reacted to this Share this post Link to post Share on other sites
SteveHobart 57 Posted November 25, 2020 It probably isn’t mate. It’s been about 18 months and, even though I haven’t run it, I’ve taken a while to get to this point. So I would suggest Warantee run outSent from my iPhone using Tapatalk Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 25, 2020 It probably isn’t mate. It’s been about 18 months and, even though I haven’t run it, I’ve taken a while to get to this point. So I would suggest Warantee run outSent from my iPhone using TapatalkWell maybe you should of mention motor has been sitting for 1 1/2 years.So I take it you never spun up the oil pump through the dizzy hole to lube the cam and get oil pressure BEFORE you tried to run it? I'll leave you with it.....Sent from my S21 using Tapatalk Share this post Link to post Share on other sites
SteveHobart 57 Posted November 25, 2020 Ha ha Before I ran it I:- Filled the Oil Filter- Put a drop of oil down each cylinder - Spun the oil pump to prime it- turned it over a few times without fuel and plugs- checked oil in the top end (yes) - put it together and tried to start itSent from my iPhone using Tapatalk Share this post Link to post Share on other sites