Broken Honda

[Dale_Tan]

Hi everyone,

I have a honda 8hp fourstroke and hit a rock at full noise causing the motor to tilt upwards. No damage to the propeller or to the lower leg, but I was unable to start the motor, on closer inspection, I noticed that a few teeth on the timing belt are missing. Would this result in bent valves/rods or damaged pistons? hopefully only the timing is off. Has this happened to anyone with a fourstroke? If so, what damage occured internally?

[NQCairns]

Hi Dale ring Honda and ask them what the piston to valve clearance is on that model. You might easily get away with it - depending. Worst case is probably a full head rebuild it takes not much of a piston bump to damage/warp a valve, small dints in the piston tops are not a problem but are a clue. If the specs from Honda are overtight then you will have to pull the head. Alternatively you could find a mechanic with a bore-a-scope and have a look for any marks on the piston tops and if clear take a chance? If you look around for the machine shop and handle the posting/delivery yourself you could possibly near halve the total cost of the head recondition if needed. good luck. nq

[clutter]

Put a new timing belt on it and retime it and give it a start. You'll soon find out if you have bent anything. It could do a couple of things, start and run fine - no problem, start and run like a chaff cutter - problem bent valves maybe, not start at all - problem badly bent valves and no compression. Actually, once you have replaced the timing belt and timed it correctly you could give it a compression test and that there should tell you the story. Get the correct compression specs from Honda or a dealer but remember yours may be slightly lower but not heaps. Troubles with compression and the head comes off.

Cheers, Clutter

[NQCairns]

Good advice the compression test idea clutter, it's just grand when tried and true basic car mechanics relates to an outboard motor.nq