Okay guys i'm going to start helping my friend work on his 84 phazer, heres the problem i can't figure this thing out.. the sled starts up good runs good for about 10-15 miles. After that the sled starts to loose power and you get a popping sound coming out of it. Sounds like she is loading up.. When i take the plugs out they look really good a light brown color. I'm thinking it can't be a carberation problem because it would probably run proorly right from the get go and the same thing if it was the electical system. Also, it was using plenty of oil so i'm kinda puzzled on where to start?? Has anyone had this problem before?? open to all opinions... ???
Thanks,
adam

Sounds like its getting hot. check the fan belt and make sure its tight. :sly:

a phazer running like sh*t, thats not a suprise. lol. every person i know thats ever owned an older phazer has had nothing but problems!

What year is the sled .... and have you ever had the motor apart . You could have excessive carbon build up . Carbon is bad in 2 ways it insulates and keeps heat in , and 2nd ... it raises the compression ratio to creat more heat . the carbon can partially block your exhaust ports .. Another thing you could check .... and this happened to me with my phazer .... a bafel in the muffler broke off inside ... Good luck ....

Have the carbs rebuilt or do them your self its cheaper you just may be suprised! So many people have problems and so many are just dirty carbs .

I wouldn't even fix the damn thing buy a new yamaha and screw putting a bunch of money into a sled that is gonna be nothin in a 2 years.

We bought a 84 at the auction last sat. New plugs and she'd run great, then she'd foul out the fan/mag side. Did this a few times. brother pulled both carbs off and cleaned them. Has run fine since then. I've been told to replace the Fan belt also as they brake then the motor overheats and we know what that does to a fan motor. Cheap insurance I think.
Caleb

I had a 90 PZ that did about the same thing. Ran great cold & then ran like crap. Pulled the heads and a chunk about the size of a thumbnail was busted out of the top of the piston on the exhaust side. I think a ring stuck and hooked the exhaust port. After she'd warm up I think it was loosing compression. Rebuilt it and sold it to buy my sxr. No regrets there. :D

a phazer running like sh*t, thats not a suprise. lol. every person i know thats ever owned an older phazer has had nothing but problems!

I kind of agree, the older phazers did have some problems, but yamaha did work on them.

As far as this sled goes, maybe the jets are wrong? Check the clutch guard for specs and adjust accordingly.