# 300 Top End



## TanMan (Jan 27, 2012)

I bought a 1990 fourtrax 300 that didnt run for $450. Now ive got it all tore down and it turns out the timing chain came off and it bent the valves and put dents in the piston. Now my question is while im here should i put a big bore kit/high comp or just leave it stock? what all should i do while im this far in it? Also a gr maybe? Its gonna be a mud/water bike so it will probly get sunk a few times if that matters. I'm new to the 300s and idk much about them yet but i wanna built this one right.


Thanks


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## TanMan (Jan 27, 2012)




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## walker (Apr 5, 2009)

i would just rebuild it stock and put a 54% gr in it .. then go enjoy ..


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## 02KODIAK400 (May 16, 2012)

these 300's are bullet proof you will probably here that alot. like walker said stock and a gr would be fine


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## Trips (May 5, 2012)

yup stock top end is good, I still have to get me GR


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## CRAZYCRACKAZ71 (Oct 8, 2011)

id rebuild stock. thats what im doing to mine now and putting a 7" dusty Nueville lift on it with 3 axle paddles on 31s. gunna b bad when im finally done.


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## jctgumby (Apr 23, 2009)

That's a good lookin' 300. I like that blue and it doesn't look to be faded too much.


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## 02KODIAK400 (May 16, 2012)

CRAZYCRACKAZ71 said:


> id rebuild stock. thats what im doing to mine now and putting a 7" dusty Nueville lift on it with 3 axle paddles on 31s. gunna b bad when im finally done.


are you building the lift thats goin be a bad 300!!


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## CRAZYCRACKAZ71 (Oct 8, 2011)

02KODIAK400 said:


> are you building the lift thats goin be a bad 300!!


 
no one of the guys from around my home town will be building the lift. i will be sure to put up some pics of the lift when its all said and done


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## TanMan (Jan 27, 2012)

Alright sounds good I'll go back stock. Just havnt decided on the 18% or 51% gr yet. Prolly gonna have 28s or 29.5s. 
And yeah the plastics r good I like it cuz everyone else's r green or red so I had to have blue.


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## jctgumby (Apr 23, 2009)

My 350 is green and I am considering changing it to the Honda Orange plastics. And as for the GR, if you are gonna run 29.5's you will want a little more than the 18%. If you run 29.5 skinnies you could probably do the 23 1/2% and be alright.


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## wood butcher (May 11, 2009)

go with the 54% and 31's


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## TanMan (Jan 27, 2012)

Ok I have a couple more questions. What timing chain should I get? The Honda is $120 and the pro x is $60. Also where do I get the gear reduction and how much is it gonna be?


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## 02KODIAK400 (May 16, 2012)

alot of these 300 mud bikes i've seen has had timing chain out of a 250sx or big red very few people make these gr most of these are made with honda 300ex parts and have been machined i think the gear reduction cost about 250-300 for 18% and about 400-450 for 54% i think it will have a hard time pulling 29.5 with a 18% GR so if going to break it down for gr id go ahead with 54%


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## walker (Apr 5, 2009)

tan man contact gotmuddy on here he builds gr . if it was me i would buy the 54% . that way you dont buy the 18 be disappointed then have to buy the 54 .


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## Trips (May 5, 2012)

TanMan said:


> Ok I have a couple more questions. What timing chain should I get? The Honda is $120 and the pro x is $60. Also where do I get the gear reduction and how much is it gonna be?


Go honda, I broke 2 chains one off ebay and one other chain. Third time I spent the money and got a Honda chain, well worth it not to be bending anymore valves after snapping a chain......


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