07 FLHT 103

if you had a scissored crank would the timing marks on the crank and cam sprockets still line up when the piston is at TDC?

I got a bad feeling....

 

Wild guess mark won't change, but won't be accurate. Gears are still on shaft, which didn't change????

Curious.

 

The marks will still line up, but like said. They won't be correct in relation to piston position. But the difference would hard to detect by just looking. and if it is obvious enough to see that its not where close you've probably already got your answer with a horribly vibrating bike, and crank run out bad enough to scar your cam plate.

 

What is it that you see is giving a bad feeling that the crank has scissored...???

 

Not vibrating, oil pump not scarred but...installed cams last weekend, started OK but bogged down between 3500 and 4000rpm, then ran ok between 4000 and 5000rpm but topped out at 5000rpm. I parked until today.

Took it apart today and sure enough, front cam was out one tooth. So in preparation of pulling rockers, pushrods, lifters etc. I put each cyl at TDC prior to disassembly. Rotated the rear tire while covering the spark plug hole with my finger until I felt the pressure stop, then I confirmed with a straw.


The timing marks for rear cyl TDC lined up, confirmed with finger over spark plug hole, then straw....BUT...when doing the front I noticed that when the piston stopped pushing air it was still not at TDC. There was no compression for the remainder of the stroke. So I just rotated the engine until the piston was at TDC and the lifters for the front were on base circle.

The logical part of me is thinking/hoping it was because my cam timing was off maybe the exhaust valve started to open earlier, releasing the pressure before the piston was at TDC? But the pessimist part of me started thinking maybe my crank scissored. I know that doesn't make sense because even if it was scissored, it would still have compression the whole stroke..

Anyway, while reassembling each cyl today, I just went by my sprocket timing marks while checking lifters were on base circle. Didn't bother with straw and covering the spark plug hole with my finger.

On start up, it started instantly, but Idled at 1500. As it warmed up, the idle slowly dropped to normal, but is still kind of surging 50 or 100 RPM. I have a VERY loud ticking noise. Sounds like a collapsed lifter. It sounds like the exhaust lifter for the front cyl. Which is weird because these lifters were fine last week. Can't shake the crank scissoring thought though.

Anyway, I'll pull the tank and front rockers off tomorrow. I hope it's a lifter. Normally I can't collapse a lifter with a screw driver, if I did have a bad one I'm assuming I could?.

 

Read my previous post



Bottom pic is front cyl when it stopped compressing. But because it was not at the end of its stroke I'm putting my money on the exhaust opening on the mistimed cam sprocket. Buts it's freaking me out

EDIT: Crap, maybe it was at the end of its stroke and that's where Timing marks lined up, can't remember now

 

Do you have a service manual ?? you gonna need one ...
i hope you are not calling anything in these pictures ...TDC ...
do you understand that both rods are on the same crank pin in these motors ..???
Please ..get a manual ..soon...

 

Forget about scissored crank. Forget about what cylinder is at TDC! Just line up the cam/ crank dots and put it together!
If indeed the front cam was off, you best check for bent valve via a leak down.

 

I'll have a look tomorrow. Rotated rear tire with the plugs out nothing was making any noise

 

You'll know when you start it up again. Either it'll run on 2 cylinders or it won't.