My 8hp suzuki wont go in gear

my mower did the same thing i used it until it broke and replaced it

surging when running is most likely normal ,they have a governer that control's the carb & rpm so it wont over rev. It has a paddle near the fly wheel to pick up wind from it when running hooked to the carb with a small lever and held stable by a spring. Check to see if the spring is too tight or sloppy. 8 hp is a pretty big motor and a kick back is not really un expected. But a plastic handle is kinda cheesy, a rubber or a wooden handle would be better.Good thing you have electric start!

You may not be deep enough in the water and it really is cavitation.

May want to check the lower oil for metal as a Mostly worn out gear can do that

It's normal for a gearbox in forward to "click" in one direction and be firm against the motor when turning against the gears normal rotation.

this is the govenor and its not complicated but somewhere along the line its come adrift with advance unit which is under the flywheel as well ,have another look and you will see what i mean take the flywheel off and give it a good inspection and you will kick yourself as its so simple but if your not sure and do it wrong then it jumps off when you open the throttle

is that on the remote control lever ? if yes then adjust the throttle cable to push against the throttle stop on the engine end so when you select gears it only moves when you go to accelerate ! mite need to adjust the carb pickup to align with mark on main lever that moves the timing rod to the trigger under the flywheel !

The shifter linkage has a two piece plastic / nylon bushing at either end of the gear shift tube that goes from the gear shift lever to the transmission. As the bushes wear through normal usage the gear shift becomes sloppy. The bushes at the gear shift lever end usually wear out first.
You may have to drop the exhaust pipe to access the underside of the gear lever as there is not a lot of space to work in above the exhaust.
To replace, remove the securing nut and through bolt where the underside of the gear lever U section attaches to the tube. Pull down the tube and the worn bits of the bush will come out. Place the new bushes in either side of the tube and put tube end back between the U section. Replace the through bolt and nut. If still a little sloppy, you may have to do the transmission end bushes as well.

This sounds like a valve body spool is hhanging up. It's that block you see bolted to the belly inside the trans. Check the vacuum modulator vacuum hose for vacuum or leakage.

Short answer...not too tough.
Longer more useful answer...
Get quality urethane replacement.
Put car in 1st with gear lever.
Block wheels and climb under with (I think10mm and 13mm) wrenches.
Undo grub screw on coupler (to linkage).
Undo through bolt on coupler.
Push linkage forward and remove bits.
Replace bits with new ones and replace through bolt.
Have friend carefully put shift lever in about 1st gear position and guide coupler onto other shaft.
Tighten grub screw.

check the shift lever where it goes into the transmission. a lot of times, the lever will get sloppy where the roll pin goes through and it won't shift into till. sometimes you can drive the roll pin out, pull off the lever and peen the holes over. sometimes you have to drill the lever and shaft and put in a snug fitting bolt and nut. OR, the chain driving the tines is broken, and that means a new transmission. hope it's simple

you could need a throttle linkage adjustment. first check to see if your ram will start in "park" and "neutral" only. if it starts in any other gear=faulty neutral safety switch. replace. ok, now check linkage for proper adjustment...with engine off and in park...remove intake housing..disconnect cableend from attatchment stud on your throttle body..slide cable off the stud (carefully)..verify that the transmissionthrottle lever is fully forward (idle) position..and verify that the lever on the throttle body is at curb idle pos..insert small screwdriver under edge of the retaining clip and remove..center the cable end on attatchment stud to within 0.04", or 1mm. install retaining clip onto cable housing..check cable adjustment..be sure trans throttle lever and throttlr body lever move in sync with each other.