Gtx 951 pistons

[Walkeracing960]

Here are a few pictures of my pistons in my 2000 GTX 951 ME, this is through the rave vavle. Do these look bad to you? They only have maybe 10-15 hours on them.

 

[mikidymac]

Lots of carbon on them, looks too lean in that short of time.

 

[Walkeracing960]

Here are better pictures, what's going on on the side of the pistons? Also that scratch dosnt look good on the last picture. What do you think

 

[mikidymac]

Are these new pistons in fresh bores? They have a lot of wear for only 10 hours.
What oil?
Did you refurbish the entire fuel system and carbs?
Why did the old ones fail?

 

[Walkeracing960]

So the entire file system was cleaned when rebuilt but some how the guy I bought it from had got painters tape in the gas so that slugged up the filters again on the spin on filter and internal carbs. I completely relearned the fuel system last week and took it back out for a test ride but it's still falling flat on its face about 5500 rpm. But it will power through it and run great. But the fuel selector is bypassed. And yes completely rebuilt because the cooling line came off and messed up the old engine. What is happening on the side of the engine. Would all this damage have been done from the crap on the filters causing it to run a little lean? What worrys me is the ski is still running the same and cutting out at 5500 rpm. When under a load.

 

[mikidymac]

Absolutely from running lean. I hate to have you run it because you can be doing more damage but if you pull the choke a little at the 5,000 and it runs better it indicates running lean. I would still suspect fuel starvation at higher rpm. Also are the RAVE valves moving?

 

[Walkeracing960]

I tried pulling the choke slightly and it didnt seem to really help. And I suppose they are. When I took the springs out of the rave caps the ski was dog slow on the bottom end. Then once in higher rpm it opened up pretty normal. With the raves out it didnt bog but that's probably because it had no power to it.

 

[mikidymac]

I still say carbs are not correct.

 

[Walkeracing960]

Took carbs apart again and I believe I found my issue. God I hope so. Trash clogging up float bowl

 

[mikidymac]

Took carbs apart again and I believe I found my issue. God I hope so. Trash clogging up float bowl

You know these dont have a float or a float bowl, just busting your chops.

What did you find inside?

 

[Walkeracing960]

Sorry, I'm learning terminology as I go here. First time really in a set of carbs. But I'll post a before and after.

 

[mikidymac]

Looks clean so far, make sure you check the little filters on the other side. IF it was mine I would be installing new genuine Mikuni carb kits and needle and seats to be safe.

 

[Walkeracing960]

Yes the filters are out. I zoomed in so you could see the clog that I found. The one with a little light is before and the after is after I cleaned it.

 

[mikidymac]

Glad you checked them, easy way to fry a new top end.

 

[Walkeracing960]

I'm upset becuae I'm afraid that already happens. I paid someone to clean my carbs and when becuaee it was having issues. It would run only idle. Well I got it back and I could drive it but it had that hesitation under full load and he said it was nothing to worry about. I kept driving it while working on things such as cleaning the raves. New plugs, new spin on filter, 1/4 off plug wire, cleaned tank and bypassed selector valve. Still nothing I did fixed it so I decided to take the carbs off for my self and give it a look and find this. I'm afraid my new top end is already gone. I belive you have seen the pictures already.

 

[SabrToothSqrl]

Well, I paid someone to do carbs for me, the one part I didn't know myself, and after 3 tries and YEARS of never hitting the top RPM it should. I took them apart myself, learned carbs, and actually bought new ones and installed with correct jets, and wouldn't you know it, the thing SCREAMED.

I hate to also bring other bad news, but someone did "just the top end" on a 951... you will get between 1-50 hours out of it. They like to throw the cranks if you don't do the whole engine.... it is 18 years old...
I've seen top ends last a season. I've seen them last a weekend...

 

[Walkeracing960]

It has a new crank as well. So the engine was completely new. I hope this thing runs good this weekend.