need help with a 1986 200hp black max!!!!!!

[pwerwagn]

I have a 86 200hp black max hung off a 85 fineline centurion tunnel. about 5 years ago, the buzzer went bad, and after some stupidity on my part, I blew it up due to lack of oil. I rebuild the entire engine, at the time thinking the only option was to buy a used block. the rebuild set me back about 6250$. <br />last summer, the boat started to run strange. top speed was only about 60 on the GPS (normal is about 77mph). I thought I either had a plug go bad, or a head gasket. I pulled the head and I the top left cylinder (looking from the back) had a hole in the piston on the intake side. The cylinder is trashed also. <br />Is this caused from running lean or from detonation?? Can you re-sleeve just the one cylinder or do I have to rebuild all 6?? it only has about 150hours on the new top end. <br />any other suggestions are greatly appreciated!!!<br />thanks in advance!!!!<br />-Jeff Argo

 

[andy6374]

Re: need help with a 1986 200hp black max!!!!!!

Out of curiosity, what RPM's are you runnin?<br />Damm that boat flys!!!<br /><br />-andy

 

[pwerwagn]

Re: need help with a 1986 200hp black max!!!!!!

Well, I limit it to about 6,000 with the 21" quicksilver on it (my ski prop). with that prop, at about 4,000' altitude, it will run about 70. <br />with the 26 pitch chopper, it only turns about 57-5800. It rarely gets spun above 5200, though, and most of its time is below 4500. Its a horrible rough water boat, so it spends a lot of time going slow!!!!<br />also, next go-round Im gonna mix the gas/oil. no more injection. I have to mix for all the jet skis anyhow, so I may as well do the boat too. <br />--thanks again!!<br />--Jeff

 

[andy6374]

Re: need help with a 1986 200hp black max!!!!!!

I blew out a Black Max before and it was the oil injection that failed. I always premix now. Lesson learned.<br /><br />-andy

 

[pwerwagn]

Re: need help with a 1986 200hp black max!!!!!!

so did you rebuild yours or buy a new powerhead?? Some people are telling me that I can re-sleeve that one cylinder with a steel sleeve (not nik-a-cil), and be done with it. others say you have to do all 6 with steel if you do one, because of balancing issues of the different ring materials between the 6....<br />also, what is the max safe RPM for this motor??<br />--Jeff

 

[andy6374]

Re: need help with a 1986 200hp black max!!!!!!

I bought a rebuilt powerhead. The WOT operating range for that engine is 5300-5800 RPMs. I have no clue about re-sleeving (I haven't made it that far in my engine repair projects)<br /> <br />good luck<br />-andy

 

[phatmanmike]

Re: need help with a 1986 200hp black max!!!!!!

you can re-sleeve. but before you do, go to screamandfly.com and check their buy & sell forums, you may be able to get a used, ready to go block, cheaper than you could have this one sleeved.<br /><br />youll be suprised at how much merc v6 info their is over there

 

[pwerwagn]

Re: need help with a 1986 200hp black max!!!!!!

Jeez!!! that looks like the place to go for info on mercs....<br />thanks for the heads up....<br />--Jeff