BRed 2011 Big Red Engine Revs But Won't Go [SOLVED]

[fmjnax]

I just acquired a 2011 BR with a known issue that it sometimes wouldn't drive, almost as if the transmission disengaged or the clutches are worn. I drove it around a bit and did a few different drive tests and I think there's more to the issue. After letting it warm up a bit, it almost always takes off like it should. However, I have NEVER noticed the machine to shift into 2nd (or 3rd, for that matter). It hits the rev limiter in 1st (maybe around 15-20mph?). Then when you stop and try to drive again, 95% of the time the engine revs up but the machine doesn't move (or barely moves). Sometimes I can feather the accelerator to coax it into moving fast enough to match the rpm's and then it feels like maybe it shifts and drives like it did before stopping. It doesn't seem to matter if I shift to N/R or if I put it in either 4WD modes or 2WD. If I shut the machine off entirely for a minute then it seems to get back to drivable mode, but all of the above presents itself again.

Researching the issue mostly pointed to being oil-related so the first thing I did was drain the oil and replace it with Valvoline ATV/UTV 10W40. I started at the min level and gave it a quick drive to take note of how it performed and then I added a little more and did the same procedure. Even with it slightly over-filled, the issue persists. I have NOT changed the oil filter yet as I have to wait for one to be shipped.

I checked every electrical connector I could find and didn't notice anything broken or out of place. No lights on the dash (confirmed they all work). Fuses are all good. I haven't checked any relays or solenoids yet. I got the machine with the full expectation that I would likely be tearing the engine down, but I would really like to explore all potential causes before I get to that point. This is my first sxs so I don't know what those potential causes could be.

Thoughts?

 

[Admin]

 

[HondaTech]

Sounds like an oil pressure issue.

I had one recently with similar symptoms that was sucking sludge against the oil pickup and blocking it off. It was super intermittent, the telltale was complete loss of oil (engine and trans) pressure when the machine would stop moving.

The downside is the oil pickup is between the crankcase halves.

 

[fmjnax]

Sounds like an oil pressure issue.

I had one recently with similar symptoms that was sucking sludge against the oil pickup and blocking it off. It was super intermittent, the telltale was conplete loss of oil (engine and trans) pressure when the machine would stop moving.

The downside is the oil pickup is between the crankcase halves.

That was my next thought and I already have a pressure tester on the way. I downloaded a service manual and found all of the oil pressure test information. I see what results from that.

If it does end up being oil pressure, how difficult of a job is it to split the crankcase to clean the screen? I have fully rebuilt 2-stroke lawn engines and larger 2-stroke outboard engines so I'm not a stranger to the overall process.

 

[HondaTech]

You'll need a few special tools to pull the converter. But the the hardest part is getting that thing out of the frame.

 

[fmjnax]

Just so that others searching for this same problem aren't left at a dead-end (like I was in my research), I ended up NOT checking the oil pressure and decided to pull the entire engine for a rebuild. It started blowing smoke like crazy, especially under throttle, so I suspected a top-end issue. I noticed that the air filter was missing entirely so it's quite possible some dust got into the engine, a ring failed, the valves are out of spec, etc. I'll just do a total teardown and inspection and take it from there. If/when I find out what was likely the culprit to the shift problem, I'll post back.

 

[fmjnax]

I have split the crankcase and I do believe I have found the problem! These strainers are quite blocked, I would say.

What do you think? Clean them up and re-assemble (aside: I'm rebuilding the top-end and fully cleaning the engine as well) or would you check anything else while it's all apart? Should I worry about disassembling the clutches and checking spec on them?

 

[HondaTech]

Id replace the oil pump pickup screen, I've seen them suck the mesh up to far and cause problems later.

If the other one isn't torn, I'd clean it, its a drain strainer.

As long as the clutches don't look burnt and haven't caked up the baskets they are probably ok. With the crap in the engine, id disassemble the clutches and clean behind the pistons.

Also look at the oil pump for damage and check the converter seal ring for damage. Replace all orings for sure.

Inspect camshaft for lobe wear and cam buckets for damage.

 

[fmjnax]

Ok, time to revisit this. I have completed the engine rebuild and have the machine running (had to replace the starter as well). The problem is only half resolved. It no longer revs without moving, however, it still won't shift at all. Stuck in first gear and will hit rev limiter at WOT. Still no engine light (though I know it works because the first start I didn't have a connector fully connected so it blinked out codes). Compression is perfect. Engine is running great. Oil pressure seems ok (I don't have a tach so I had to guess at 5k RPM's, but it was over 100psi). Mechanically speaking, I don't see anything wrong. I didn't do anything with the shift solenoids so maybe it's something in there?

What else could cause a no-shift? At this point, I think I'll just leave it as-is since I will almost never be using the machine at a speed high enough to need the additional gears and I really don't want to pull the engine out of the frame again. If there are other possibilities that I can check without pulling it again, I'd gladly love to hear them!

 

[fmjnax]

Some more information after doing some more playing with the machine. I added a little more oil (sitting about half way in the middle dipstick indicator) and now it shifts reliably between 1st and 2nd. Still no shift to 3rd, but I'm not hitting the rev limiter anymore. Everything else is working beautifully. This will mainly be a farm machine so not the end of the world if this is all we get out of it, especially since I am still under $2000 total investment. Eventually I will either figure it out or give up, but I'm always open to suggestions or things to check.

 

[fmjnax]

I guess I posted too soon today. I threw a Hail Mary and connected! Unfortunately, I don't know what task was the winning ticket or if it was a combination of them, but the end of the story is that the problems are solved!

- I changed the oil (first oil change after the full rebuild). It looked good and my magnet didn't pick up any metal.
- I changed the oil filter again. This was my main guess as the culprit. The oil filter I ordered before was the wrong one so I did my best to clean the old one and put it back in while I waited for the right filter to get here. The old one didn't look too bad so I'll probably cut it open tomorrow just for grins. I finally put the right (new) one in today.
- I took off the shift solenoids and ran through the teardown and rebuild specs in the manual. Everything looked great and all of the solenoids tested correctly. Still, I completely tore it down, cleaned, and rebuilt it.

Fired the machine up, let it warm up, and went cruising. The machine now shifts through all 3 gears perfectly. No stutter or hard shift. I clocked a max 40mph on the GPS, with 33-35mph being more average. Never hit rev limiter, never bogged down, always took off with authority after stopping. The ONLY issue is that after a long WOT run, I get a backfire or two when letting off the gas as it downshifts. I'm sure the valves need work, but I'll save that for another day. This will do for now!

Thank you everyone for your help through this journey, and hopefully this information will be of use to someone else down the road.

 

[Wileyolebuck]

Thank you for posting all this. My 2010 is doing the same thing. Will change the oil and filter tomorrow

 

[Muggster71]

Thank you for posting all this. My 2010 is doing the same thing. Will change the oil and filter tomorrow

I’ve been researching a similar problem for a while now. I’ve come to the conclusion that my cam lobes are worn so I’m in the process of getting part numbers and whatnot. Anyway, i ran across a post about low oil pressure on these and clogged filter screens. The poster, as a last resort, drained oil, poured 3 quarts of gas into crankcase, drained that, poured a gallon of diesel into it, drained that, blew all that out with air, put oil back in, ran it, drained it, filled it with oil again. Evidently that cleared the screens and fixed oil pressure problems. I will find link and post it for future reference on this thread. I think I will do this procedure also, instead of pulling whole motor out. I don’t want to put new camshaft, buckets, chain and tensioner if I have clogged oil screens. I don’t really want to pull the motor either so this seems like a good alternative.

 

[dblizzard]

Id replace the oil pump pickup screen, I've seen them suck the mesh up to far and cause problems later.

If the other one isn't torn, I'd clean it, its a drain strainer.

As long as the clutches don't look burnt and haven't caked up the baskets they are probably ok. With the crap in the engine, id disassemble the clutches and clean behind the pistons.

Also look at the oil pump for damage and check the converter seal ring for damage. Replace all orings for sure.

Inspect camshaft for lobe wear and cam buckets for damage.

Definitely ck the cam lobes for excessive wear.