gearbox/trans problemo

Hi all, i have an xj650 trike ive built for wifey (see pics) i have used a reliant axle and all seems fine untill i accelarate hard or basically take off fast, the transmission or gearbox seems to slip and make the worst mechanical noise ever!!!
I have fully rebuilt this engine (early 16G motor) including the trans and have been told it could be the extra starin of carrying 2 wheels causing the inner gear spring thingy to slip and judder but "hey im asking cos i not know"..

 

is it kind of a clicking sound?? I have had that once when I misadjusted the clutch cable after removing and installing the carbs. WHen the clutch is pulled in take a 3/4"(19mm) wrench put it on the arm that the cable attaches to on the engine side. gently turn it clockwise with the clutch pulled you shouldn't have much play at all I would say 1/16th of an inch or so. If you have more adjust it till you don't then test drive er and see what you have.

 

Cheers, its a definate knocking/grinding or if ya like a slipping of cogs kinda noise. I have been told its the drive gear with the spring (centre gear) but im just not sure, clutch is fine but im now pulling near twice the xj`s weight and with an axle and 2x17inch wheels im getting the feeling the box cant cope!!!!

 

Thats the sound I had a week ago upon reassembly. Once the clutch is locked in it's up to the gears they are kinda hard to strip. Is this in all gears or just a few? It may be time to remove the clutch basket and check things out maybe beef up the spring in which you are speaking of. Mine was out of adjustment pretty bad but only took 2 min to adjust up right and no slipping. It doesn't cost anything but time to give the cable a bit more slack and see what happens. Mine was actually too tight when I had the noise and the slipping of cogs describes it best. Maybe someone else will chime in with some better knowledge for ya. Once you are in gear tho the weak link should be the clutch plates as you have a gear to gear mesh.

 

Clutch all checks out ok, even went to the trouble of completely re-assembling the basket and all ok. I guess next is the gearbox but im gonna run it a few miles more as it runs fine if i dont gas it like mad from the off. Im still leaning towards the final drive as ya say say the rest is meshed gears and ive seen old XJ`s with the middle gear spring totally wrecked... :evil: 8O :wink:

 

Hi all, took trike out yesterday for a blast and my fears of gearbox probs where realised!!!!. The drive started to give like clutch slip but with a loud clicking noise (similar to a chain driven bike with a buggered chain), then the gearbox locked up preventing gearghange. After a few hearty atempts and a few blips of the throttle it kinda jumped into gear and drove again, This happened in 1,2 and 3rd (didnt dare go any higher) but if you tootle along at walking pace it rides fine, all this noise etc only kicks in when i accelarate!! ANYONE A CLUE????????????????????
THis motor has been totaly rebuilt and all the gears where like new and we all know XJ box`s are usually bullet proof hence why so many get triked :wink:

 

Well, there are two things I have found on my transmission that fix problems w/o opening it up.

Number one is to have fresh oil in it, and enough, and the right type. Mine really likes Valvoline 20w50 4 stroke motorcycle oil, much more than 10w40, and much more than other brands. If my trans is acting up, clutch is slipping, or it just plain doesnt feel right, then it is time for an oil change. I also find that the bike burns just a tiny bit of oil, so after about 1,000 miles, I add a pint or so, and the trans starts acting better w/o a complete change. In your case, I would do a complete oil change with a good motorcycle oil, and check the level carefully before I did anything else.

The other thing to check is the clutch cable. It is easy to set it so that the clutch does not completely engage / disengage. Playing around with the adjuster will help this. On mine it is a 12mm nut on the cable right by the clutch lever on the transmission on the right side of the bike.

Short of these two suggestions, I guess your opening it up and digging in.

Good luck.

 

The trike looks great. Can you post some more detailed pictures of the rear axle and shocks? I have been wanting to make a trike out of my XJ1100 for my wife.
Wish I had some sugestions for your trans problems, I'm no expert on the 650's

 

Hi all, i finally sorted this problem out :lol: I decided to rip the motor down and was more than happy to find (strange i know but...)2nd gear was totally stripped of its locating dogs. So luckily i just happened to have a spare cluster from a very low milage xj750! I was always led to believe the 650+750 are same gears but they aint!!! The 750`s fit same but are 2or more teeth larger per gear, good thing is it seems to suit the trike and she goes like STINK 8) I mean this is only a normally aspirated xj650 turbo motor so its lowish compression, but the mods ive done seem to make the thing pull really well in all gears and upto now ive had it dash a 0-60 time of under 5 seconds
Ill try post some more pics but there seems to be a file size limit and all my pics are high res!!!

 

Saw this old thread and it gives me hope for my trike build ideas. does anyone know this person or have any info on how this turned out?