[bbottarini]

Just got this '87 TRX 350. Was working well for the first couple of rides going over stumps, rocks and up steep grades like a champ in low gear. On my last ride she started bogging out with very little pulling power (no torque any forward gear).
What could be the issue here? Should I give this an over haul (ie: carb, jets, oil, filters, new gas)? Or is something like this transmission related? (Reverse gear is still very powerful). I got this mainly because it already had a plow on it (I take the plow off for free riding) and I will certainly need that SL gear torque for when I plow this winter.

Thanks all...

 

[shadetree]

Just got this '87 TRX 350. Was working well for the first couple of rides going over stumps, rocks and up steep grades like a champ in low gear. On my last ride she started bogging out with very little pulling power (no torque any forward gear).
What could be the issue here? Should I give this an over haul (ie: carb, jets, oil, filters, new gas)? Or is something like this transmission related? (Reverse gear is still very powerful). I got this mainly because it already had a plow on it (I take the plow off for free riding) and I will certainly need that SL gear torque for when I plow this winter.

Thanks all...

with it being a '87..i would say you need to over haul just about the whole bike..carb..adjust valves..clutches..centifugal clutch arms..fuel filter..drain gas tank ( screw under the very bottom )..go over just about everything.

 

[bbottarini]

Thanks for the quick response, what would you say is the best service manual for this bike?

 

[MNRedneck]

I've always had good luck with the Clymers manuals

 

[shadetree]

Thanks for the quick response, what would you say is the best service manual for this bike?

clymers is what i use..only thing i hate about them..one..they don't show every step by step on some things..you have to jump from chapter to chapter for covering one task..lol..and second..they should print the pages in color..you can miss alot of arrows they try to point out to you on a page.

 

[shadetree]

Just got this '87 TRX 350. Was working well for the first couple of rides going over stumps, rocks and up steep grades like a champ in low gear. On my last ride she started bogging out with very little pulling power (no torque any forward gear).
What could be the issue here? Should I give this an over haul (ie: carb, jets, oil, filters, new gas)? Or is something like this transmission related? (Reverse gear is still very powerful). I got this mainly because it already had a plow on it (I take the plow off for free riding) and I will certainly need that SL gear torque for when I plow this winter.

Thanks all...

after re-reading this..it puzzles me that reverse is still working good..but forward gears isn't doing so well..if it was a tranny issue...such as clutches..centrifugal clutch..it would do it in reverse as well as forward gears..that is unless..the clutch disk are worn in a forward pattern ?..i highly doubt this though..i've never seen this happen in all the bikes i've worked on anyway. ..does it lose power in all forward gears ?..or from..say 2nd and 3rd up ?..the reason i ask is..when your in 1st gear..you don't have to give it much throttle to move it..but once you get to 2nd and so forth..you pretty much have to gun it..these bikes aren't made for speed..that's for sure !..they were designed to haul..pull heavy loads..alot of farmers used these in all the years they sold them..simply because they had so low torque at very low speeds..this is why you don't get any problem in reverse..because your not using alot of throttle..reverse is a very low gear..and 1st gear is considered super low to really be honest..before you go tearing into it..and replacing alot of stuff..i would over haul the fuel system..carb..fuel filter..check your fuel pump...make sure you get that out of the way..see if that improves the bike..i'm betting it does !..i've owned 2 of these bikes..i simply love the way they can pull just about anything you attach to them..lol..they are work horses for sure...mine..i just restored..is a '89 trx350d foreman..and it started out as a basket and box case..lol.i wouldn't trade it for a brand new one off the show room floor !

 

[Helmut]

after re-reading this..it puzzles me that reverse is still working good..but forward gears isn't doing so well..if it was a tranny issue...such as clutches..centrifugal clutch..it would do it in reverse as well as forward gears.

This is the reason I haven't posted in this thread. This confuses me, as well. I don't know of anything that could cause this. I understand that reverse is a very low gear and that it don't take as much throttle, but first gear (super low) should be about as low as reverse and it should run similar in low. I don't know what the problem could be.

 

[mlauk]

Could the brakes be locked up?

 

[shadetree]

Could the brakes be locked up?

could be..but..he would notice this as he tried to go backwards as forwards..i would think anyway..as a mater of fact..i just ran into this very problem with mine..the rear brakes froze up on me..and it would not move at all..soo..it's not his brakes.

 

[shadetree]

after re-reading this..it puzzles me that reverse is still working good..but forward gears isn't doing so well..if it was a tranny issue...such as clutches..centrifugal clutch..it would do it in reverse as well as forward gears.

This is the reason I haven't posted in this thread. This confuses me, as well. I don't know of anything that could cause this. I understand that reverse is a very low gear and that it don't take as much throttle, but first gear (super low) should be about as low as reverse and it should run similar in low. I don't know what the problem could be.

well..think about this..if your moving in reverse..your not giving it much throttle..which in turn..means the centrifugal clutch isnt spining as fast is it would be going forward really fast..soo..thats why i was leaning towards the clutches..something isn't right with them.

 

[bbottarini]

reverse also lacking torque

The wheels are not locked, the bike rolls fine.

I tried riding this weekend again, after draining the gas gas tank, changing the oil and blowing out the fuel filter (need to order a new one). I also cleaned the carbon out of the rear of the muffler.
I am thinking that the fuel system (carb, etc) may be the culprit, however when I first started riding this bike after I bought it three weeks ago it was pulling like a champ. During one of the rides I bumped into a tree in a tight (very slow) turn and proceeded to bend the front rack and right fender a little bit. Shortly after this was when the loss of torque started. I notice that I never see the cooling fan turn on (maybe caused by bent fender)... could an overheating oil system by causing any power loss? I know that after 87' Honda put in an engine cutoff in the event of oil overheat but not '87 or before.

Thanks all....

 

[bbottarini]

couple of more things, it does not seem to rev really high, almost like it is governed somehow. When it is cold (just started) the torque is fine, after it has heated up the torque goes away and the bike barely crawls in any gear. (which is why I mentioned the oil heat and the cooling fan)

 

[Helmut]

I would test the ignition coil and clean the carb to begin with. Also when it warms up and the problem occurs, try pulling the gas hose from the fuel pump and make sure the pump has good flow. Maybe the fuel pump is getting hot and not pumping properly.

 

[bbottarini]

found the cause

As it turns out, a carburetor overhaul did the trick. It seems that that last guy who tried to rebuild this carb forgot to attach the throttle valve to the valve arm. So basically the throttle valve stayed in the dropped position allowing no gas through the carb. Replaced all jets etc while in there anyways...
Bike runs great!
Thanks all!
:icon_ lala:

 

[Helmut]

Great, glad you got it fixed!!