Results of not knowing what you are doing BBK

[ratdog]

a kid came to me this morning that lives a few streets over.  He bought a BBK and installed it him self.  Only he could not get it to run.  Only took a few min to figure out the problem, ( no compression) and guess the problem.  So this is the valve I took out of his head.  I think you should be able to see it’s slightly bent. Kept the valve off the seat by a good .100” inch.

so why did this happen?  He didn’t loosen up the valve adjusters befor he tightened down the rocker arm assembly/ head. The partially open valve seems to have caught on the lip if the cylinder, and as he wrenched it down, it bent the valve.

nice guy I am, we are starting over.  I’ve pulled the engine down to the case. He also has the two compression rings reversed (has the black one on top.  And when he couldn’t get the second small ring in the oil ring, he just figured it did really need it.  I mean it’s just a spacer or something, right?l. Just FYI, when I was pulling it down, I found he also had the cam timing off one tooth.

i don’t know if I can get a replacement valves ( it oversized). 

We’ll get this done!  Just have to get some damn head gaskets!

[90GTVert]

I've seen some oversized valves sold on eBay before. If you can't find anything, heads aren't terribly expensive if it's Chinese.

[ratdog]

That’s what most likely will happen, but there is a guy near me that used to have a scoter shop (now sells out of his basement) and he has a ton of “take off” parts, so I’ll dig thru his stuff first. I’d like to keep from having to put any money in this if possible ( well other then a head gasket)and has a paper route. I did that when I was a kid, so it’s a soft spot for me (G)

[GrumpyUnk]

Put the valve in a vise, and get out the hammer. Certainly you can make is square again. As a last resport, I would actually consider doing that. But. There is risk that the valve will separate into two pieces, and then cause the poston to separate into 432 pieces. Some very small, and likely one or two large pieces with ventilation to the crankcase and visibility of the small end of the connecting rod.
I would suspect that the valve touched the piston rather than the edge of the cylinder. If it touched the cylinder, then how would it ever get past ... no matter the valve clearance it was adjusted to. It moves along the axis of the stem, and should have little deviation. That path would have to go past the cylinder 100% of the time... unless I missed something.
As far as the color of the piston rings, I stay unconvinced that color is an absolute. I base this on images as I searched... The rings in one set were marked with one or two dots, and the other the same, but the colors of the rings did not match... I think... So, I went with the description of function. The ring that had the higher tension was the ring #1. IMO. So I compared, and the ring that 'rested' at a larger diameter was the one I put into the top groove. Hope I was right. The colors were opposite between sets.
I asked the vendor multiple times what the marks meant, but got diversionary answers, and a referral to this site and 90's posts... without attribution, as I remember.
tom

[ratdog]

OK. Happy ending (I think). I found a valve that was the right size, but it was a 69 mm valve instead of a 64 mm. The guy had a real cute little lathe, so I made it into a a 64 mm valve. The keepers seem to be holding it just fine. Cleaned up the head and leaped in the valves. I dint like the “hone” job on the cylinder (just looked like they spun the hone didn’t go up and down no cross hatch) so I did a light honing. Put everything to back together. Battery was dead (he left the key on) so we kicked). Kick started it (4thkick!). Ran it for about 10 min at between 3000 - 4000 rpm, then the kid took it for a test ride. A few min later, he went wizzing by the house a 45 mph!

He claimed its 15 mph faster then ever before. I. Asked him to ride it around for an hour or two and come back. Three hours later he came back and we set the mixture and idle stop, so he is good to go.

He also cut my lawn for me. Heck, I may not have to cut the lawn for the rest of the year!

[chino]

Sweet,you the man ratdog.😀 I enjoy helping young people out when they take the initiative to do/try something on there own,IMO knowledge learned should be shared.By any chance did the kid break a belt while riding before the bbk? I've bent valves when the belt broke at wot before,instant rpm increase and bamm.!

[ratdog]

No, this was a new head. Came with the big bore kit and has oversized valves. I did not see the head before he put it in, but I don’t think it was shipped that way. Plus the way he said he tightened it down. Instead of spinning the nuts in by hand then using a wrench for the last couple of turns, he said he gasps to use the wrench “forever” to get the bottom two nuts tight. ( BTW, he did not have a torque wrench). I actuly had him practice with the torque wrench on a different bolt, so he would know how to do it. When I’m putting bolts into Alum, like putting thr engine back together a always use a couple of things. A bit of anti seize in the threads and a torque wrench to prevent overnighting the bolts.

[ratdog]

Got a real nice surprise! Kid rolled by and gave me a gift card to Outback. Goes to show that there is some hope for kids now a days

[GrumpyUnk]

good news ... for a change.

nice.
tom