How do I know when my engine on my 400 needs to be rebuilt? Are there any warning signs that it is gonna blow up on me? I have heard that when the scramblers blow up they usually do a lot of damage is this true? I'm sure that some of you have some input as to what u should have done if u blew ur engine. Any info will be great thanx, and also I will be adding an exhaust sometime this spring.

 

How old is your scrambler and how hard have you ridden it? Hard starting is a clue as is smoking and a overall loss of power too.more noise than normal isnt good. To really know how worn out is you need to do a compression check. If you kick start this quad is it getting easier to kick over? That would show some ring wear.

 

Theres no kickstarting the scrammy but you need to do a compression check. Your local autozone to see if they have one you can rent. You can use the rope to pull it a few times real hard but I would use the starter button with the throttle wide open and see what your compression is. If you have blue smoke like mywifesquad said you may need to rebuild. If you do have hard starting check the obvious first with a new sparkplug and a clean airfilter.

 

Compression test

Noise in bottom end

I ride my 400 almost daily, its been 3 years and I haven't been into the engine yet.

On my old 400L Polaris I had 1640 miles and it was making a heck of a rattle. Bored and hone and put new Wiseco piston in. At 5600 miles I sold it and it was still running strong.

I think the secret to long engine life is a long warm up before WOT or WFO!

good luck............handycap

 

I have a 2000 2 stroke scambler also, mine blew up last summer, there wasnt a whole lot of damage, but it wasnt because of natural causes either, i barely ever drive the thing it just sits in my garage and somebody was gettin revenge on me and snuck in my garage and threw sum sugar in the tank so it blew up, but there wasnt a lot of damage

 

I owned mine since 2000 also and its still all stock

 

It is a 2000 I just bought it this July I know that it was trail-ridden by a husband and wife who both had 2000 scramblers this was the husbands not sure but estimated to be around 700-1200 miles or so on it. It smokes a little blue when its cold but i assume its jsut cuz its a 2-stroke that it does that, once it warms up a little bit it doesnt smoke at all. The engine usually always fires right up. I don't know much about loss of power since I have only had it about 7 months or so. I do ride it kinda hard when im at my friends house cuz im racing but im fairly gentle on trails. Once I add performance parts will I need to worry about blowing it up with an exhaust and reed cages. Also what sould compression be at so I know what to look for if I do a test on it. Thanx for all ur help!

 

yea my scrammy smokes a lot of start too, but its just cuz its two stroke and its just been rebuilt, i still drive my scrammy relatively hard tho but by the way you talk bout it, seems you wont need a motor job for a while

 

Best bet is to rebuild the topend if you are not sure if a previous owner hasnt already done it and put in a aftermarket piston.A stock piston can and will break the skirt off with little or no warning causing major damage.$300 is good insurance that it has a good piston in it.