I split the lower case on my FJ1100 to install a transmission with undercut gears to fix my slipping second and third gears. The engine has been running well and has good compression but when I got it apart I can see the crankshaft and bearings have more wear than I expected.the surfaces still feel smooth to the touch no gouges. I found the last time the cases were assembled they placed the silicone sealant too close to the bearings and covered some of the oil channels an the back of the two outside crank bearings.plastigauge shows the crank to bearing clearance is between about .0022"-.0028",out of spec for sure. The engine has 72,500 miles on it. I eventually want to rebuild it with a big bore kit and ported heads but I was planning to wait until next year. I would like to ask those with experience if it makes sense to replace the bearings without regrinding the crank so I can get another fifteen or twenty thousand miles out of it or would I be better of leaving the bearings alone and just running it until I rebuild the whole motor? Thanks in advance for any advice. Travis Legg
Run it. :good2:
Randy - RPM
Quote from: racerrad8 on October 04, 2020, 11:12:05 AM
Run it. :good2:
Randy - RPM
Thanks Randy . That's what I wanted to hear.
Speaking on behalf of LAMike; attempt rebuild approx 3 days before a rally you plan to attend.
I am aware of the superstition about working on your bike less then two weeks before a rally but my slipping gear problem had reduced my shift points to 4000 rpm. Before I began the work I prepped my back up bike with new tires ,fixed the speedometer,new rear brakes,and a new headlight plug and bulb. I took it for a test ride and the fuel petcock failed to shut off the fuel when the engine was stopped at the same time the carb floats began to leak so I replaced the vacumn diagram assembly and installed my flatslides on the bike . Now the bike is road ready and no longer slow. Meantime I have the cases back togethor on my black fj and I'm pretty sure I will have it back in the bike by Thursday. Ian and I are planning a trip up the coast now that the rally had to be cancelled.
What size RS's are you running?
Currently I am running RS-38 carbs. Before that I had a set of RS-36 carbs from the eighty's . My bike ran great with the old RS-36 carbs but they developed a hanging idle problem that I haven't been able to solve yet,so I bought a new set of 38's a year ago. The 36's ran perfect with the factory recommended jetting and needle settings. The thirty eights have required different needle settings and main jets to run right. I don't know if I'm getting more horsepower with the thirty eights yet I'm still playing with the main jets. When I put my flatslides on my yellow fj1100 it went from being much slower than my black fj1100 with the flatslides to being comparable to it. I highly recommend them.
Quote from: T Legg on October 17, 2020, 10:19:56 PM
Currently I am running RS-38 carbs. Before that I had a set of RS-36 carbs from the eighty's . My bike ran great with the old RS-36 carbs but they developed a hanging idle problem that I haven't been able to solve yet,so I bought a new set of 38's a year ago. The 36's ran perfect with the factory recommended jetting and needle settings. The thirty eights have required different needle settings and main jets to run right. I don't know if I'm getting more horsepower with the thirty eights yet I'm still playing with the main jets. When I put my flatslides on my yellow fj1100 it went from being much slower than my black fj1100 with the flatslides to being comparable to it. I highly recommend them.
I ran 36, 38 and 40's. In the end I stuck with the 38's for years. The one change was a different needle jet. The RS's are the "small block Chevy" of carbs. I currently run FCR's which are great but are more complicated to tune.
Quote from: JMR on November 18, 2020, 10:23:08 AM
I ran 36, 38 and 40's. In the end I stuck with the 38's for years. The one change was a different needle jet. The RS's are the "small block Chevy" of carbs. I currently run FCR's which are great but are more complicated to tune.
What needle jet did you use and why. My RS 38's have the standard Y-6 needle jet . Did you drop down to the P-4 used in the RS 36 carbs? Did you also use the 9DZH1jet needle to match the P-4?