| Author | Message | ||
     Mhlunsford |
So my M2 started sputtering - carb fart at around 3K pretty bad. I noticed that the idle changed a lot when i pulled off the plug to front but very little for rear cylinder. Also there was a time when there was a lot of ticking come from the head. I changed the intake seals twice and checked for leaks - none that I could find. so I pulled the heads just to see, the valves do not leak - heads where done about 3 years ago. Swapped plug wires. I am wondering if I have bad tappet causing intake not to open all the way ? anyway way to tell ? | ||
| Two_seasons |
I'd change the plugs first. Then I'd run a couple of ounces of clean tranny fluid through the oil for 100 miles or so. Then change the oil, run it for another 100 miles and change again. Keep us posted. | ||
| Natexlh1000 |
Sounds like what my ironhead does when the points are fungled up and lopsided. It may be worth a look at your timing cup/sensor. Perhaps something obvious&easy in there? | ||
| Firemanjim |
Did you do a compression check? | ||
| Bluzm2 |
Try 1/2 can of Seafoam in the oil. I've personally seen it do miracles on sticky lifters. Had a neighbors V6 Buick motor clattering VERY badly, you could hear it coming down the street. So bad it sounded like a bad rod knock. Before I even had half the can dumped in, it was already quieter. Buy the time the can was empty, the racket was gone. 4 of us were standing there dumbstruck... The stuff works.. Period. Worth a shot. If it works, run it for 50 miles or so and change the oil. | ||
| Mhlunsford |
I am going to change out the lifters. I went with a NRHS 1250 kit some 20K miles ago. The barrels look good, just wondering if I want to pull the barrels completely off and look at the pistons. If I do this, do I have to hone the barrels again or can I just slide the pistons back in ? | ||
| Harleyelf |
The cylinder walls should be fine, but you very well might nick a ring. I wouldn't crack the head torque just to get at the lifters. Might not even have to remove the cam cover, just lift with a magnet. When you get the new lifters in, take the old ones apart, rub the stains off the sliding parts, and soak the re-assembled lifters in a jar of motor oil. They'll make good spares. | ||
| Brother_in_buells |
You could leave the pistons in the cylinders. If you remove them from the cylinders ,your going to disturb the piston rings and could make it into a oil using engine. | ||
| Ratbuell |
Unless he installed collapsible pushrod tubes, he has to pull the heads to get the lifters out. Bases won't come out without removing the tubes; tubes don't come out without pulling the heads. Only workaround is bolt cutters - cut the tubes and install collapsibles when you're reassembling. If it is a valve issue, and it's keeping the cylinder from "working" like it should, you should be able to see / measure it by turning the engine by hand, with the rockerbox cover off. Also roll your pushrods on a pane of glass to make sure they're not bent. And make sure your rocker arms are tight and the hold down bolts aren't stripped out of the heads. | ||
| Mhlunsford |
I have the heads off, with the pistons still in the cylinders. I just wanted to make sure my valves and cylinders are OK. Heads were done some 20K miles ago when the 1250 NRHS kit was done. I have have a metal base gasket. I am going move the pistons to lowest part of the cycle and inspect the cylinders. Clean up the carbon on the cylinders and the heads. I got some lifters coming I am going to go ahead and replace. Then install new comet head gaskets. Get the pistons in TDC and install the rockers. Do a compression check. Then finish. My original problem: was very little power coming from the rear cylinder. My rear cylinder has very little carbon while the front has some. The rear was burning little leaner than the front, but both intake valves were speckled with some carbon, not the clear white you would expect. | ||
| Mhlunsford |
Second question: I want to make sure by intake seals actually seal. Was considering using a little blue gasket sealer along with the new seals ? | ||
| Gmaple |
Don't have to pull the heads to get the pushrod tubes out. He will have to pull the rocker box assembly then remove pushrods then tubes. | ||
| Harleyelf |
Exactly. And the book says to remove the cam cover but that's only necessary if one is really stuck. First try lifting them with a magnet after taking the pushrods and tubes out. If you do take the cam cover off, drain the oil first. Retorque the rocker assemblies one at a time with the engine rotated to TDC of the compression stroke (both valves shut). |
