Want to build up my 85 350x. need some info

[dream3wheeler]

So i got this 85 350x for a parts trike along with the 86 a bought. Only thing wrong with it is the previous owner put way too small tires on it and reved it up too high. cracked the piston in half, broke the conecting rod and im not sure if it needs a new crank or not but ill find out soon. he lost the valve cover for the top of the cylinder so ill have to find one of those sometime soon. Heres what i was thinking for a bit of build. 10.25:1 compression 81mm wiseco piston kit with gaskets, think that might give it a bit more of a bite than the 8.5:1 compression piston. Then getting a 86 transmission and slipping that in there for the extra gear...is that possible? Bigger tires maybe 25's if i can find the proper rims to put them on or id just stick with some 22 size itp holeshots. and smaller sprockets...any idea on what i should get as far as sprockets and chain goes and where can i get them? Any bigger carb ideas? im sure the 86 carb would work but id like to find something even better if theres anything out there. I've also done a little reading and i heard about using a 400ex aftermarket rev box...any info on that? And last but not least....POWROLL....what happened there? they were on my favorites and now whenever i click on it, nothing comes up...didnt they use to have a kit for the 350x? give me some ideas on this...ive got some money to spend and id like to fullfil my racing desires to beat all the quads around here with a monster 4 stroke trike. any ideas are helpful. thanks guys.

[jays375]

No need to switch the transmission.Tires go with 20" and 14 tooth front sprocket.Stock on rear sprocket.Buy a good quality chain.A 400EX will get you good results.Just spend time on jetting.Ditch airbox lid and frame intake tube.Provided you put a good exhaust on it also.Get your crank rebuilt.The 10.25-1 piston will work well.Have your head checked out.See if the guides and valves are good.Left over money I would put into the trike.Get the brakes and suspension fixed up.Don't look at receipts until your done.

[dream3wheeler]

Sounds pretty basic. Would the transmission work though? That extra gear is really nice to have and Im sure with the new piston, 400ex carb and front sprocket it'll probably beat my stock 86. Any news on a 400ex rev box? Might even just try that on my 86 plus a 400ex carb and see how that works out.

[TheRealFatShady]

They both have six speeds, even the 1985.

If he broke the piston in half, you should really inspect the head for valve damage and the cam journals. Also, you'll have to check you cylinder, it's likely to need a bore job and then the stock size 81mm piston won't fit.

And I do recall once reading about how the 400ex rev box may only work properly on a 1986 350x and not the 85 model, but I'd have to check again to make sure. Not even sure where it was that I had read that.

[goump1995]

Have a spare 350X Headlight assembly you'd want to sell?

[dream3wheeler]

Didn't know that, thanks shady. I haven't really inspected the inside yet but ill know soon enough what piston size ill need. As far as the rev box goes Im not sure if its worth trying out but i might experiment with it just to find out if no ones got any answers. And im sorry goump i don't have a spare at the moment. Any more ideas on modifications. Maybe cams or crank work?

[Dirtcrasher]

No need to switch the transmission.Tires go with 20" and 14 tooth front sprocket.Stock on rear sprocket.Buy a good quality chain.A 400EX will get you good results.Just spend time on jetting.Ditch airbox lid and frame intake tube.Provided you put a good exhaust on it also.Get your crank rebuilt.The 10.25-1 piston will work well.Have your head checked out.See if the guides and valves are good.Left over money I would put into the trike.Get the brakes and suspension fixed up.Don't look at receipts until your done.

Yep, I agree.

85/86 same tranny. I rev the hell out of mine so maintenance or other factors may have blown it up. I'm all for 12:1 but keeping fresh juice is for Ryan Vilapoto, not me...............

18" tires wind out awesome!!

[dream3wheeler]

So guys. All the upgrades that can be done only really give it more torque and horsepower? Speed won't really change much? If that's the case i think i might just get a stage 3 amr rev box for a 400ex and put it on my 86 and also put a 400ex carb on it, then sprocket change and nice holeshot tires and a dg chrome exhaust.

[Vealmonkey]

It would be a good idea to reinforce the frame in the weak spots, look for threads on what people have done. How crazy do you want to get and how big is your budget? Inverted front ends, longer swingarms, custom built shock, just to name a few. Big Bore and Stroke for the engine. You can have over 500ccs' if your budget allows. It's only money, right? LOL

[jays375]

Think the $ scared him a little.The rev box will do nothing.What was suggested to you will make a big difference.Horsepower and torque equal big fun.If you go big it will cost you.Trust me I know.

[dream3wheeler]

I looked at big bore kits and sending my crank in to get it worked on. I don't mind the money. It'd take 2 grand just for the engine. Other mods like shocks and swing arms would easily add another grand or more. The only thing that concerns me is speed. With the extra torque and horsepower would it even really get me to go any faster? Maybe by a few mph but these machines have a limit don't they? For speed it might be easier to just convert a newer trx450r into a trike. But i don't have the knowhow to do that.

[Dirtcrasher]

Some mods are a nice compliment. Too many you'll find it is a bit too fast for MX style riding. The suspension cannot take it.
If your just tearing up some trails, your good :D

[dream3wheeler]

Well as long as i can beat the raptor 450's and most of the quads around here id be perfectly content with the speed. Ill throw some money at it and see where it brings me. Id like to make this happen this summer but i don't know where i can get any of the work done around here. No one in town does small engine work. Id probably screw something up if i tried to do it all myself. I don't have the tools either. Im going to college this coming fall for that stuff so afterwards ill be able to do some crazy stuff.

[userj8670]

Speed is really up to you. Depeding how much torque and horsepower you have is a big factor, your gearing is the next biggest as you need to have the torque to get you up there with those gears and then i would also say tires.