How reliable are the z400 engines and frames becauseI am gettin an alright deal on a z400.

 

boy this question has never been asked....... do a little digging you will find this topic they are great machines and great motors as discussed many many times.

 

if your going to take the time to come to this forum you could at least answer the dam question^^^^.... the engines are very smooth with even power.... the frames in earlier 03 models were prone to frame cracks but late 03's and 04's have had the bugs fixed and are excellent bikes

 

I broke my frame (my bad) now the motor makes some noise but there are good and bad in all of them its still 110% better than my old warrior

 

ive been out on my 2004 about 8 times now clearing jumps and riding hard and no frame cracks so far. .... there may just be a few built that were defects.. not sure

 

I have a full season of mx on mine and the motor was still mint when I tore it down to put in my 440 and do the head work. The frame did start to crack but I can say I have crashed good a few times I dont think it was a weak frame I think the bike was just ridden hard. suzuki took care of it and im still riding and wouldent trade it for anything that is out now. With the motor that is in it now there are no 450s that pull away anymore so Its also very competive now also.

 

only the early production models had frame/axle problems. If ya get one, get an 04 and gusset it if you plan to race, you wont have any problems.

 

Will the 440 kit cause it to overheat?Also getting the rev mod and uping the rev limiter to 8000 from 7000 reduce the life of my atv?

 

For overheating, you may need to use a more diluted (eg more water) mix in your coolant.

Anytime you increase the red line of an engine, it increases the stresses on the engine. Will it reduce the engine life? yes. Will is reduce it significantly? Depends on how often you ride at those high rpm's

 

K well I dynoed mine at the dealership I work at and I tell you what you lose power before you hit the stock rev limiter so its just a waste of money. You cant prove it anyother way then a dyno. i mean yes you could degree the cams differantly to get the power more up high but I cant see how you need to it does so good like it is. I cant see spending the money on a rev box I do good in the mx races I do and I did that on a stock motor this year im sure ill do better with the stock rs in my built 440.