Announcement
Collapse
No announcement yet.
FZ1 Rod Bearings
Collapse
X
-
FZ1 Rod Bearings
As some know I have removed the engine from the FZ1 to investigate the lower crankcase trying to diagnose my engine noises. I have found the the bottom rod cap and bolts, as well as the surrounding area od the number 3 piston rod is a burnt black color. The other 3 are a normal clean appearance. To any who are familiar with rod bearing issues does this sound like a blown rod bearing?Current Bikes:
2001 Yamaha FZ1 (bought same one back)Tags: None
-
20201005_182456(1).jpg
The other 3 look like this.Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
Forum LongTimerGSResource Superstar
Past Site Supporter
Super Site Supporter- Mar 2006
- 35640
- Torrance, CA
The huge majority of failures like that trace to oil starvation. There is a very good chance that the crank is scored on that journal. Hopefully you can find some good, but cheap, parts to fix it up.Ed
To measure is to know.
Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182
Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846
Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf
KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection
Comment
-
Originally posted by Nessism View PostThe huge majority of failures like that trace to oil starvation. There is a very good chance that the crank is scored on that journal. Hopefully you can find some good, but cheap, parts to fix it up.Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
My first question - are there any metal particles on the oil pump pickup screen ?
If so, then yes, you've done a rod bearing for sure. Until you split the crank you don't know what you're dealing with.
I've done several of this family of engines - FZR1000 based range. The early ones had a well known problem of stretching the rod small ends but later rods don't do this.
None of them have what I'd call well finished cranks. When you do split the crank, look at the edges of the oil holes at the crank surface. Frequently they've been left sharp.
This sharp edge peels the oil film off the bearing leading to early failure.
If you buy a used crank, I'd prep it properly, radius the oil hole edges and get it linished by an engine shop.
Rod bolts can be reused - they're not torqued to yeild point. If the shells look good, reuse them too.
Comment
-
Originally posted by GregT View PostMy first question - are there any metal particles on the oil pump pickup screen ?
If so, then yes, you've done a rod bearing for sure. Until you split the crank you don't know what you're dealing with.
I've done several of this family of engines - FZR1000 based range. The early ones had a well known problem of stretching the rod small ends but later rods don't do this.
None of them have what I'd call well finished cranks. When you do split the crank, look at the edges of the oil holes at the crank surface. Frequently they've been left sharp.
This sharp edge peels the oil film off the bearing leading to early failure.
If you buy a used crank, I'd prep it properly, radius the oil hole edges and get it linished by an engine shop.
Rod bolts can be reused - they're not torqued to yeild point. If the shells look good, reuse them too.Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
Originally posted by GS1150Pilot View PostThose motors are readily available in pieces or as whole units. Great lumps, those.
https://www.ebay.com/itm/Crankshaft-....c100005.m1851Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
I think I may need another crank. Looks scored.
20201011_154007(1)(1).jpgCurrent Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
That thing really got hot. Before pulling the cap off, I could grab it and rattle it back and forth, hense my mysterious engine rattle. One half of the bearing was rotated halfway overlapping the other half.
20201011_155528(1).jpgLast edited by ddaniels; 10-11-2020, 05:45 PM.Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
-
Originally posted by GS1150Pilot View PostThose motors are readily available in pieces or as whole units. Great lumps, those.
https://www.ebay.com/itm/Crankshaft-....c100005.m1851Current Bikes:
2001 Yamaha FZ1 (bought same one back)
Comment
Comment