Yeah your pic from disassembly showed the cam in backwards - perhaps that was the initial problem and a machining change may have been implemented with the 2KR to avoid the possibility
Not sure on the in-line 4's but on the twin OHC single... those notches on the top cam journal are used as timing marks.
I know what you're saying but I'm a bit confused. They're in the right way in the pic if you take a close look at the engine orientation...?
It may be the pic, but it looks as through the timing ends are on the right hand side of the engine (when sitting on the bike), pic taken when you first disassembled it - circled in red.
Ah so that's what you meant. I can see how it looks that way but with no indented dot in the top that's the opposite side of the cams not the flalred out section.
Well the moment of truth arrived... bit smokey though. How I missed that FZ(R) roar! Guess it's time for the test ride so be putting the front end/exhaust/airbox back on soon.
Yeh she's not running too badly. Starts really easily but struggles to hold idle a bit but I think the carbies need a balance. The motor itself pulls pretty strong/smooth but pours out smoke from the exhaust when cold (missing exhaust gaskets) it seems to settle when warm so the rings are probably pretty worn. I'll keep an eye on it, especially that head gasket but she'll be an interesting runabout for the time being.
Starting to look a bit more respectable now, It seems to be holding idle a little better although it is still a bit erratic.
Ok so I'm at the stage where I've had a good play. Got my care package from bike bitz in NZ with a new dash, headlight and screen so now everything is ready. I decided to throw some coolant into the cooling system to check the head gasket from two directions, water in the oil and oil in the water. Unfortunately but not surprising I think there either was or is a small leak as it looks like a bit of oil is in the coolant. I then drained the oil and found it was slightly off colour, so although passable for a "thrash" bike I think it will need a new head gasket. So I ordered another, same as the FZR250 being both are 1HX engines ($32), and while I'm at it I put an order in for some new chinese rings as this thing when it starts up blows smoke like crazy. Once all that is done and running, the carbies need some work - definitely a balance. I'll then fix up the awful looking patchy frame and terrible paint job on the engine parts and I think we'll have a pretty good looking bike. Sorta looking forward to it as the riding position compared to the FZR is much more bearable to me so we'll see how it all cleans up.
Isn't smoke on startup valve stem seal's, and/or possibly worn guide's ? Did you notice the valve stem's were wet/oily when you had the head off? Worn ring's wont smoke less once it's warmed up Have you done a compression test ?
If only on start up definitely stem seals or guides. My guess would be stem seals. Easy enough to do when you have the head off to do the gasket. I would do a compression test as well. Sent from my iPhone using Tapatalk
It smokes a lot on start up then settles down but still smokes constantly. I have a set of stem seals for the FZR I could use I suppose. Just a question, how do you get them off though? Pushing them on seems a lot easier than pulling them off...
I use long nosed pliers... once you have the valve springs off and the valves out... de-coke it at the same time... maybe lap the valves depending on their condition... it can become a never ending job until you have done a full engine rebuilt... Problem is... after doing the valves and stem seals.. you will need to check valve clearances again..
I should just get the FZR engine back together and going before I do the FZ I think... and get the 400 on the road in the meantime.... it never ends either way!
So I decided to rip it down after calling Yamaha and finding the HG is the same as the FZR. I also spoke to AHL (china) about the rings and they assured me they are the same, I have a new set here for the FZR so I thought I'd throw them on the FZ while I'm waiting for the other set. Getting down to the pistons and I ran into a problem though... These pistons are NOT the same as the FZR. They're taller, and the oil ring groove is wider meaning the jaggered oil ring from the AHL set is actually too small to use. That is annoying. It also made me wonder if the rings are actually the same, I couldn't trust what came out of the FZ as the rings were visibly buggered and having no information on ring gaps etc it is troublesome to assume. I tried putting the chinese rings on there but the bore seems to have too much friction when I try and put it back together, a problem I never had with the FZR so I'm starting to think the rings may have to be different. I've spoken to my sister in law who has sourced a japanese service manual for me and I might have to put off further work until I get that and check all the specifications. The confusing thing is the head and bore look exactly the same as the FZR, as well as the cams... although I have not measured the rods yet but I can't see why they'd be different. Maybe it's just the pistons...?