engine repair

[Knobber]

I need some big help.  I removed and replaced my rear cam chain tensioner plunger a few months ago.  Pretty straight forward work.  I followed the shop manual and guidance from a member on this site.  Pretty straight forward (or so I thought).  When I tried to start the bike after reinstallation the motor would not start.  I exhausted all trouble shooting I could think of and some members on this site suggested.  I finally broke down and took it into the Honda dealer shop yesterday.  They called me and said the timing was off upon reassembly and that I had now damaged the valves and the motor was going to require a complete valve replacement on the rear two cylinders!!!!  Total estimate was upwards of $2800!!!!

 

I can not imagine how the timing would become changed when replacing the plunger.  The mechanic on the phone said something about the motor not being at the proper position during plunger removal and this would allow the motor to "roll back" and thus timing gets off.  The shop manual does not say that the motor needs to be turned or timed to any specific setting (i.e. #1 tdc) before removal and installation.  The only proof he really offered of this is that compression was low on the cylinders.  I asked again how timing can become that off as it is a chain on teethed gears and it would have to jump completely to move like that.  He didn't seem to have a solid answer for me.  I am truly in disbelief this could or would happen.  I am also wondering how he could say I have valve damage when he only had the bie for a few hours so I can't imagine he was able to visually inspect the valves?

 

I really need help here.  I want my bike running again but I also don't want to spend a lot of money on work I truly can't imagine is necessary.  I don't think they are trying to take me but I am wondering if they are just looking at the work I did and the low compression and jumping to a solution (a very expensive one!).

 

Any help/guidance/information would be greatly appreciated.

 

Thanks,

Matt

[MBrane]

Sounds suspicious to me. I would simply tell them you're not able to afford a repair like that, and get the bike back. Then check cam timing yourself to see if in fact the chain has jumped teeth.

[Rice]

+1

I'd take the bike back and do the following: 

1. Remove spark plugs and turn the engine by hand to hear for sounds, like pistons hitting valves.  If NO noise, go to Step 2. If YES noise, go to Step 3.
2. Check timing.  If off, adjust and try starting again.
3. Buy used motor from ebay or c-list