Yamaha TRX850 Enthusiasts Forum

hi guys. been going over my new TRX and there's only a couple of things that spring to mind (apart from a rusty rear shock, but that's superficial).

1) when cold or still warming, the engine will pop from time to time. it's not on every revolution of the engine, just every 8-10 seconds or so. it doesn't seem to do it when warm or while accelerating, but i do get the occasional burble-pop on overrun (which i assume is completely normal).

is popping when cold normal? i'm not worried, just wondered if it needed a tune-up.

2) the Haynes manual (which i'm sure you've all seen) suggests using engine oil below a certain grade, to avoid clutch slip.... i've spent some time looking around and all major outlets sell oil of a higher grade than that suggested.

to be specific, the manual suggests nothing higher than grade 'H'... however, Halfords only stock grade 'J' and above... (honestly, i was going to buy their slightly racier 'SL' oil but decided to check here first).

opinions? am i worrying? or will any 10w40 oil do?

Popping is common when a motor is either on choke or not warmed up enough to ensure a full and clean burn of the mixture.
As for oil ANY quality semi-synthetic 10W/40 will do, I use this one personally but don`t pay that much as I`ve a trade card :

http://www.halfords.com/webapp/wcs/stor ... yId_165507

thanks.
that's pretty much what i thought.

i'm familiar with other types of engine, but wasn't sure how smoothly the 5-valve twin ran when still cool. i'm super-impressed by how smooth and relaxing it is to ride at motorway speeds, compared to the other bikes i've ridden. inline fours are too 'peaky' to be relaxing and most cruisers tend to have a little too much vibration (down to the type of frame i guess) for my liking.

If she`s running the stock 17 / 39 gearing motorway speeds (70 to 90) do seem very relaxed on the TRX. You may find you tire of the low speed clutch and throttle juggling if you filter through traffic though.
Most folk compromise a tad on top end for a smoother time through traffic by running 17 / 42 gearing or similar (16 / 41, 15 / 39 etc).
I would advise sticking with the 17 tooth gearbox sprocket and make changes to the rear sprocket only, the chain cuts into the rubber swingarm protector more with smaller gearbox sprockets.

yeah i'd heard similar things about the gearing through my pre-buying research.

as a matter of course, i probably wouldn't touch the final drive sprocket on any bike, instead opting to tinker with the wheel sprocket instead. you get more fine adjustment that way.

cheers for the info though =).