When is a hone job needed?

[burnt-clutch]

So I finally got the head off of my Fleetwin and I’m seeing some scoring at the top of both cylinders walls, and matching scoring on the piston rings. I took the exhaust plate and bypass covers off and the piston rings have flex to them and do not seem to be stuck. Before tearing the power head down I did a compression test and the top cylinder had 70PSI and the bottom was 80. I’ve been reading a lot about the “50 cent hone job” posted in other threads and was wondering if I should bother doing the same with my powerhead or if it would be better to leave it as is and put it back together with a fresh head gasket. I’m thinking that if the rings are already scored that I might lose compression if I honed the cylinders. Let me know what you’s think, and thanks in advance!

-Karl

[wbeaton]

If you aren’t replacing the rings then don’t bother honing the cylinders.

Wayne
Upper Canada Chapter

uccaomci.com

[fleetwin]

Does the scoring match up with either the exhaust cover or intake covers? If so, pulling these covers will give you a better idea of how badly the piston might be scored of if the rings are stuck in that area. Would it be possible to post some pictures? Seems like you have a 10PSI difference between the cylinders, which is a concern on one of these small/low compression engines….
In any event, using some light emery/crocus to rough up the walls a bit and remove any aluminum transfer might help out, certainly worth a try…Simply rinse the cylinders well with WD40 or some light spray cleaner/lube afterwards.

[The Boat House]

[burnt-clutch]

Thanks for the replies. I don’t plan to restore the motor, just freshen it up so I don’t plan to go any further than replacing the head gasket. I’ll retest the compression after I get it running and see what difference it made. I bought a gasket with the copper rings that go around the top of the cylinder so hopefully that will give me a great seal. On a side note, I broke off one of the head bolts and would like to use all new bolts to for the head. Can i just go to the local hardware store and get a bolts off the shelf to replace the originals? I’m assuming a bolt is a bolt, but I’m also a novice at this. Thanks again!
-Karl

[The Boat House]

• This reply was modified 4 years, 1 month ago by The Boat House.
• This reply was modified 4 years, 1 month ago by The Boat House.

[olcah]

Thanks Tubs for the useful info on honing above. Working on just such a worn motor. As it is not worth rebuilding I will just reassemble and check the outcome.

[fleetwin]

burnt-clutch wrote:

Thanks for the replies. I don’t plan to restore the motor, just freshen it up so I don’t plan to go any further than replacing the head gasket. I’ll retest the compression after I get it running and see what difference it made. I bought a gasket with the copper rings that go around the top of the cylinder so hopefully that will give me a great seal. On a side note, I broke off one of the head bolts and would like to use all new bolts to for the head. Can i just go to the local hardware store and get a bolts off the shelf to replace the originals? I’m assuming a bolt is a bolt, but I’m also a novice at this. Thanks again!
-Karl

Don’t be afraid to “rough up” the walls will some fine emery/crocus like I mentioned. While this method is certainly not a substitute for a proper “rebuild”, sometimes it is enough to bring compression up a bit….I am not recommending pulling the powerhead apart, this can be done with the pistons in place, just rinse the cylinders out with carb cleaner/WD40 afterwards and re-oil the cylinder walls generously afterwards…. Oftentimes this crude procedure is enough to break the glaze on the walls and provide a rougher surface that will hold oil a little better, which might result in higher compression.

• This reply was modified 4 years, 1 month ago by fleetwin. Reason: addition

[oldemtr]

Why do I think the load, tensile, and yield columns, for the metric bolts on that chart, are listed in a different denomination ?

[fleetwin]

I’m sure you could find a used OEM head bolt, which is your safest/best bet….

[Author]

Posts