Question:
Dear Motorhead,
My buddies and I all say you have the best snowmobiling book of the industry, always interesting and informative. keep up the great articles. We love the tech stuff, reviews and mods.
I have a 1998 grand touring 500 liquid, not a lot of use yet though, only 2700 km’s on it, i was wondering what mods, upgrades, adjustments etc you would suggest if I wanted to spend a bit of coin and time on it to make it top notch in the speed and power department, I don’t run wide open for long periods but occassionally have to keep up to the buddies.
It is all stock right now, it seems to have got a bit slower than it was for the first few years, I use to get 140 km/h on a good day, now it’s maybe 125-130, it runs great, new belt, rpm’s in the 8200 range if held down for a few minutes, nobody around here with a dyno.
I live in Temiskaming shores, Ontario, I think we are around 1000 feet above sea level. I cleaned the raves already and am now using i-pone oil.
Barry
Response:
Thanks for your email!
You have described what we would recommend as the basics to restore your sleds original power. However, you may be dealing with a somewhat weary (albeit low mileage) engine.
I would suggest you run a compression check to see if the mill is still pumping hard. If not, it’s time for rings – at the very least. Your insertion of a new drive belt was timely however, I would seriously recommend you have both the front (primary) and rear (secondary) clutches serviced. This may be where your top end speed has gone. The rear clutch (big pulley) may need cleaning and sliding surfaces (buttons and bushings) replaced.
As well, your primary TRA is a great clutch but may simply need some service. The effects of time – in particular dampness during storage – often has a profound effect on the transmission components I’ve described.
Try these things and see what you get. Keep in mind, a lot of new tech has impacted the sno-mo-biz since your Grand Touring was born. Issues like weight and fuel economy have altered our performance expectations dramatically the past decade.
Hope this helps.
Motorhead Mark
