[galahad1212]

What could cause this issue? I can shift up from 1st to 2nd then to 3rd ok, 3rd to 4th is hard to get into and 4th to 5th seams fine. But when down shifting, 5th to 4th to 3rd is ok, cannot not get it to go into 2nd and 1st unless I shut the machine off and rock it back and forth and play with the shifter. Even when the machine is off, I can up shift to 3rd fine and have the same issues. Any suggestions? Thx in Advance.

 

[Here 2 help]

Are you having this problem while moving or just sitting still with the engine running? It is normal to not shift when the engine is not running unless you rock the machine back and forth.

Not shifting when the engine is running could be one of many things. One possibility is; the viscosity of the oil is too high. Heavy oil can cause drag between clutch plates and/or the transmission gears affecting shifting. Another possibility is the clutch is not adjusted properly or there is a problem in the clutch. Another is a problem with the shift shaft or the mechanism that turns the shift drum. Sometimes a bent or externally damaged shift shaft may cause a similar problem. Other possibilities get deeper into the engine and more expensive.

You probably need an experienced mechanic to look at it and make his best guess based on his feel of the problem.

 

[galahad1212]

Are you having this problem while moving or just sitting still with the engine running? It is normal to not shift when the engine is not running unless you rock the machine back and forth.

Not shifting when the engine is running could be one of many things. One possibility is; the viscosity of the oil is too high. Heavy oil can cause drag between clutch plates and/or the transmission gears affecting shifting. Another possibility is the clutch is not adjusted properly or there is a problem in the clutch. Another is a problem with the shift shaft or the mechanism that turns the shift drum. Sometimes a bent or externally damaged shift shaft may cause a similar problem. Other possibilities get deeper into the engine and more expensive.

You probably need an experienced mechanic to look at it and make his best guess based on his feel of the problem.

This was happening while I was moving and the bottom end is new to me. So not sure if it had the issue before I put a top end on it. I think my easiest solution is me putting another bottom end on it, I have a known good one from another project. I am using 10 W40 for oil. Its not atv oil though, gonna get some of that tomorrow. I will also try adjust the clutch tomorrow. Will try the easy stuff first. Thx

 

[Here 2 help]

If you are using 10W40, it's unlikely the oil is the cause of the problem.

Just make sure the oil you change to has the JASO rating on it (MA or MA2) - if no JASO rating, API rated SF, SG, SH or SJ will work also, and the 10W40 is recommended. Some racers like 20W50 or 15W50 synthetic, but the racers are aware of the downside and are willing to put up with it.

 

[galahad1212]

Ok think I figured out why it's not shifting. The shifter lever is not spring loaded, what I mean is you can move it up and down about 2 inches total travel without any resistance and it always rests in the down position. My other bottom end feels like it has a centering spring. I took it on a test run and if I phisically center the shifter with my foot it will sequence the next gear. So either a spring is missing or broken internally. What are your thoughts?

 

[Here 2 help]

Yeah - sounds like the return spring is broken or the spring pin came out #11 or #12 on the diagram at this link

World of Powersports' 2006 Honda TRX400EX Sportrax | SHIFT DRUM / SHIFT FORK Parts List

 

[galahad1212]

The center journal on the
head looks like it got hot and some of the metal is worn, can not find a spec in the manual for wear on the head and cover journal. Can it be cleaned up and still used or do I need to get another head and cover.

 

[Here 2 help]

Without seeing the parts, I suggest you get another head, cover and cam