I'm trying to diagnose some poor engine performance on an 03 rincon. The engine starts easily and idles fine ,but when you accelerate in drive at about quarter throttle and up it almost feels like the ignition timing isnt advancing, it burgles and pops and wont go over 30mph. It will shift through the gears both in auto and in ESP, it feels like its hitting a low rpm rev limiter. I even put the machine on stands and ran it with the wheels of the ground (no load in drive,) and still only went about 30 mph and ran rough.(through the gears as well)
When the engine is warm and in neutral it seems to rev out fine but still not smoothly and clean. I 've checked the connection at the ECM, and most connectors (all clean and tight) . I changed the spark plug, checked the carb (twice), drained the tank , fresh fuel, air filter is clean ,checked the ignition timing with timing light (all ok),
There are no trouble codes displayed and none in the memory, this machine has only 1200 miles and is babied! Am I missing something here?
Im good friends with the service manager at the local shop so I have aceess to some manuals and free advice ,without the shop rate.
But so far we havent found anything obvious, Im suspecting the ECM, but from what Ive read the only way to verify this is to replace it with a known good one.
Please help

 

there is a possibility you have an air leak thats acting up at higher rpm. try a vacume test on the carb, or throttle body. turn on kill switch, place hand overthe intake, where the air filter would be. then hit the starter so the engine turns over a couple times. this will create a vaccume in the intake. if there is no intake leak the vaccume should hold steady for a while, but if it dosnt hold a vaccume then you have a leak.

if you do this it will rule out a simple intake leak. if its an ECM that can get expensive [img]i/expressions/face-icon-small-sad.gif[/img]

hope this helps

 

My guess would be clogged or partly clogged main jet or other passage in the carb. Also check the fuel screen in the tank.

 

[img]i/expressions/face-icon-small-smile.gif[/img]Thanks for the reply folks, Ill try the vacuum test you suggested , but Im sure you meant to leave the kill switch off while cranking , Ill let you know how that goes.
As far as fuel delivery goes from the tank its good , I had the carb apart twice ,removed the pilot , main ,fuel screw, inlet needle and blew out all passages, checked the diaphragm on the slide and the jet needle is secure and un tampered with. I suspected carburetion as well thats why I double checked it before chasing other gremlins.
Again thanks guys. ..much appreciated
Canadian MIKE (maicobreako)

 

Just had one in my shop doing the same exact thing you are describing. Had the intake lobe worn off the cam. Replaced cam all is well now. Hope this helps.

 

Surely your choke isn't on, right?

 

I removed the rocker box today to check the valves and cam shaft out . Both intake and exhaust valves were opening and closing fine , but when I removed the push rods and buckets It looks as though the exhaust lobe is worn. Its blackened and there were small metallic hairs on the edges of the lobe. The under side of the push rod bucket "lifter" thingee's? looked rough and not shiny like i would have suspected. Are the intake and exhaust lobes similar in lift and duration? If they are I would say the exhaust lobe is definately smaller in Lift,and thats just using my finger as an indicator, meaning wear.
I am going to talk to my service manager buddy tomorrow to get some service info and specs. Is this a common problem on these ? My local dealer says they've seen this problem a few times on the newer POLARIS engines saying they would start good and idle but wouldnt rev out because of worn out camshaft(s), POLARIS says its from not using synthetic oil. This Rincon isnt mine and the owner told me he used HONDA oil only. I dont consider this a high performance engine in my books ,(compared to new era four stroke mx bikes) which are showing decent reliability considering there output.
Are thes HONDA cams poorly heat treated or something, as this machine has low hours with regular oil changes. Do these engines really require high grade synthetic oil.

 

The cam sets in a tray. That tray needs oil in it. Many dealer's set-up personell will stand these quads on their tail and the oil will run out of the tray. When the quad is started there is no lube there and the damage begins.

I went through this with a customer this summer who had their quad in at the local dealer 3 times for the cam going out. When I installed the cam in his unit, I filled the tray with oil before starting the quad. He has had no issues with the cam for 7 months since.

----- Gimpster -----

 

I've read about a few of these cam problems on other forums...

Let us know how the cam measures out.

 

Hey Maicobreakco I have a 03 Rincon with the exact same problems as you what did you find out was wrong? Are you in the OHIO area ? What dealer do you deal with ?