GT550 Crank Bearings

[yamahale]

Hi all, I have a keeper 77 GT550 that I have the crank out of. I am looking for info on the Cruisin Image rod kit. I realize that the OEM rods and lipped bearings are unavailable, and have researched the heck out of it and found that the aftermarket uses 5 of the 09262-25098 instead of just 2, and which replaces the 3 09262-25010 Suzuki calls for. From what I can determine, the only difference is the shield that seems to hold the oil to the bearing. There are many routes to go, I am trying to balance quality and cost. My thought is, if the rods are good to go in the kit, the $250 for the kit would be worth it just for the rods(compared to the $600 jrwdfa on Ebay wants for OEM), even if everything else had to be sourced from Suzuki, as I read the big end CI bearings are sketchy. A little background on me, I am a semi-retired bike tech since 1979 and have fallen in love with this bike, and want it reliable. I am doing all the work except for the pressing....any thoughts?

[dinogt]

I will open (and rebuilt) a GT550 cranshaft in some days so, I could answer at your question.

[yamahale]

OK, well I have ordered a set and should receive before 2 more weeks and I will report on the kit....

[tennesseetwostroke]

You can get the original style lipped bearings from paul miller racing. He has them on ebay. I have gotten two sets from them, good quality oem parts. Search for GT550 crankshaft bearings on ebay. His store is jrwdfa.

[yamahale]

Yes, but his prices are insane for the rods and bearings. I received the CI kit, looks ok but I wont be using the big and small end bearings out of it, I will spend a little more and get OEM.

[Vintageman]

but I wont be using the big and small end bearings out of it, I will spend a little more and get OEM.

+1

I am very interested in CI Rods. How will you test? I would be concerned the Big End of rod too wide ID and/or pin too small. Maybe put the pin ends in a vise and with rod and bearing on it check side to side rock. Check all three to verify quality control.

This has been a good reliable test for me over the years. I would expect new to be no more than 1mm for that rod. Sometimes this new is specified in service manuals but not often. My guess is wear limit is around 2mm side to side for that rod without looking it up. More than half the time that limit is published but again not always.

There are other things to check too, but if that fit is a bit sloppy it will run fine for a while, but wear fast than expected and if you plan to ride and keep it important IMO

Please let us know

[wavehog33]

I used CI rod kit in my GT38O last summer and with approx 1000 miles it blew the left big end bearing all over the Cherahola skyway.......the piston tested fine, but not the rod kits or the crank bearings.

[yamahale]

I used CI rod kit in my GT38O last summer and with approx 1000 miles it blew the left big end bearing all over the Cherahola skyway.......the piston tested fine, but not the rod kits or the crank bearings.

Yes I was afraid of that, I plan to buy the Suzuki roller bearings as the CI cages look cheap. I do plan to check the clearance before and after I get the Suzuki parts. I wonder if the big end pin is OK, I might go OEM with those too. Mainly I am hoping the rods themselves are good to keep the price realistic.

[yamahale]

I used CI rod kit in my GT38O last summer and with approx 1000 miles it blew the left big end bearing all over the Cherahola skyway.......the piston tested fine, but not the rod kits or the crank bearings.

BTW the Cherohala was my favorite ride when visiting the Dragon area!

[tz375]

I used CI rod kit in my GT38O last summer and with approx 1000 miles it blew the left big end bearing all over the Cherahola skyway.......the piston tested fine, but not the rod kits or the crank bearings.

Did you manage to determine the cause of the failure? One thing we found with aftermarket Honda big end bearings was that the slots in the cage were carefully rounded off in some and it others, the slot had very square edges and corners that acted as stress raisers and that's where the failures began. In other cases, the rollers were too square at the ends and those sharp corners dug into the cages and caused them to crack. too much clearnace between rollers qnd cage slots or too little are also problematic.

Any idea what the cause of failure was in your case?

[wavehog33]

I used CI rod kit in my GT38O last summer and with approx 1000 miles it blew the left big end bearing all over the Cherahola skyway.......the piston tested fine, but not the rod kits or the crank bearings.

Did you manage to determine the cause of the failure? One thing we found with aftermarket Honda big end bearings was that the slots in the cage were carefully rounded off in some and it others, the slot had very square edges and corners that acted as stress raisers and that's where the failures began. In other cases, the rollers were too square at the ends and those sharp corners dug into the cages and caused them to crack. too much clearnace between rollers qnd cage slots or too little are also problematic.

Any idea what the cause of failure was in your case?

Not 100% the rod bearing cage was gone, the rollers stayed in place, the cage spit out the exhaust. Also, the CI main bearings were junk, notchy and too much play.

[Evans Ward]

Keith- I hope you were able to keep it upright when it let loose. Beautiful views up there on the Cherohala but wouldn't want to break down there. I took my GT750 up it this year during the Meet and we rode the loop in reverse of how most do it by taking the Dragon first. I'd always wanted to try it that direction and it gives it a whole new look and feel. Hwy 360 is big fun too!

[wavehog33]

Keith- I hope you were able to keep it upright when it let loose. Beautiful views up there on the Cherohala but wouldn't want to break down there. I took my GT750 up it this year during the Meet and we rode the loop in reverse of how most do it by taking the Dragon first. I'd always wanted to try it that direction and it gives it a whole new look and feel. Hwy 360 is big fun too!

Thanks Evans
Heard it start to go so I was able to hobble back to Robbinsville to switch to the back up silver RD400. Then ripped that RD all the way back through. Good day after the switch.

[yamahale]

but I wont be using the big and small end bearings out of it, I will spend a little more and get OEM.

+1

I am very interested in CI Rods. How will you test? I would be concerned the Big End of rod too wide ID and/or pin too small. Maybe put the pin ends in a vise and with rod and bearing on it check side to side rock. Check all three to verify quality control.

This has been a good reliable test for me over the years. I would expect new to be no more than 1mm for that rod. Sometimes this new is specified in service manuals but not often. My guess is wear limit is around 2mm side to side for that rod without looking it up. More than half the time that limit is published but again not always.

There are other things to check too, but if that fit is a bit sloppy it will run fine for a while, but wear fast than expected and if you plan to ride and keep it important IMO

Please let us know

OK, seat of the pants preliminary opinion, no actual measurements....the CI rod and crankpin dry fit, with a new OEM lower bearing, nice and tight feeling with minimal rock about 1mm if that....CI bearing, noticeably looser and unacceptable(to me) for being new. The rod, pin, and thrust washers came in one sealed package telling me they are from one supplier, and the roller bearings came in a separate bag from another. That tells me the rod/pin/thrust washers are dimensionally good and the bearings are not. Also, the seals are suspect, the lips are thinner from the new OEM ones I have and will be using, and one is actually deformed and wavy. They have no brand stamped and are not NOK at least, and will get thrown out. Lastly, the main ball bearings seem nice, I cleaned a fair amount of grit out with brake cleaner before I even spun one of them by hand, I believe thats where a complaint came from someone claiming they were notchy and loose feeling. They seem smooth and tight to me and even though they are unbranded I believe I will use them, and the stamped numbers look like they are from one of the bigger companies. They do only have 7 instead of 8 balls, but hey this is my daily commuter and will not be raced or redlined a lot and I think they should be fine....

[Vintageman]

yamahale,

Thanks for doing that test!!!!!

Lately, when I do a 2 stroke crank I look for a "better" Big End bearing ( how many have you had fail in your life!).

My GT550 crank all done last year... working on gt380 crank, Unfortunately nothing better for GT380/GT250 and Very Small bearing and week point IMO... Oh well OEM for the GT380.

Got me looking at GT550 for a "Better" Big End Needle Bearing.

Here is OEM for SUZUKI RGV250 ->
https://www.ebay.com/itm/SUZUKI-RGV250- ... D3o&vxp=mt" onclick="window.open(this.href);return false;

compare that to OEM for GT550 ->
https://www.ebay.com/itm/NOS-Suzuki-PE1 ... jH&vxp=mtr" onclick="window.open(this.href);return false;

See the difference



And. yes Suz still sells Big end PIN for GT550. Under 1mm rock seams OK!