Im looking to buy a new mid sized 4x4 atv. How does the grizz 550 eps compare to other mid sized atvs.

 

as much as i love yamaha atvs, i would steer away from the grizzly. they are having fuel vapor locking issues. some people have the problem, and some do not. check out the big bear irs 400 with 28 inch tires and a 2 inch lift kit on it. that would be a lot better in my opinion.

 

HAAHHAHAHAAHAHAHAAHAHAHAHAHAHAHAHAHAHAHAHHAHA

steer away from the Grizzly, fuel vapor lock issues...ahahah

The fix is a new $2 part.

I, have never had that problem.

 

i am simply just sharing what i have heard. i know it is more of a problem in the south because of the brutal summers. that is what an internet forum is for though. getting opinions then using that information to help you decide for yourself. kudos to them if it is a two dollar part and shame on them for not installing that part in the first place.

 

If you read the reviews, the 550 uses the same chassis as the 700. The upside, all 700 acessories bolt up to the 550. The downside, it's is big as a 700 and loses 13 hp. But if you don't mud or run wide open, you won't miss the 13 hp.

The midsize in the grizzly line is the 450,

 

As far as I know, vapor lock is when fuel becomes gas(vapor) in the fuel delivery system due to heat, I believe the older 660's used to vapor lock in the carb but have not heard anything of that sort with the new 700. The 'gas boiling' issues are not boiling at all, it is simply due to a higher pressure in the tank caused by the vent check valve not releasing as much pressure as some ppl think it should. I would imagine Yamaha did this for emission reasons. As far as wether it is dangerous or not, most if not all vehicles such as cars/trucks have pressure in their tanks, and none have blown up yet so I dunno what the fuss is about.

Like was mentioned, to fix the pressure issue IF you have such an issue at all and it actually bothers you, simply replace the valve with one more free flowing, or take it apart and drill out the little ball that holds the pressure, or put a gas cap from a 660 on with the hose vent.

*Note: The 550 uses the same fuel system/similar engine configuration as the 700, so I would imagine any fixes apply to the 550 as well, provided the 550 has any such issues.

 

For '08 Yamaha went to a longer,smaller diameter muffler,and a different check valve from their motorcycle line to fix the 'boiling' issue. This works if you stick with the stock exhaust. For custom pipes there are two fixes.

1. Remove the check valve and replace with a $2.00 fuel filter.
2. Remove the tank and cover with heat resistant tape/sheeting available from Jegs or similar racing parts suppliers.

AFAIK, there have been few reports of boiling with the stock '08.

 

Can you tell me if this fuel problem is occuring with the 2007 Grizzly 400's as well? I apologize for being new but what's the appropriate fix? My gas cap has an approximately 8" long rubber tube running out of it. Is that the vent previously mentioned?

 

The new 550 is to closely priced with the 700 to bother with it.

 

Sierra 13, no the 2007 grizzly 400 is not affected-afflicted?. Just the '07 700FI grizzly. But I bet a 700 Raptor owner will chime in and complain it affects them too.