85 honda atc 250r stuff

[lightemup01]

hey guys im new and could use a little help. ive got a 85 250r and id like to put on a pipe, and aftermarket head with bigger dome. i was wondering what size jets
you guys reccomend. right now they are stock. and also what u guys think about running race fuel??

[TatTooL23]

jetting is very specific to mods and the 3 wheeler and the elevation of where u live. u cant really just tell someone what they need. the motor could be tired, intake options different, hot or cold outside temp. so many variables. u have to do plug chops as u add mods.

as for trail riding and recreational riding my opinion is that race fuel is not needed. i run 93 octane in everything.

[fabiodriven]

Why do you want a head with a bigger dome?

[250rmanfmf]

What are you wanting to do with your 250r? Racing, duning, trail riding? With pipes you have a few options. One that gets a lot of recommendations is the complete ESR exhaust. It a good overall exhaust and works great with slightly moded R's. Another is FMF. I have ran both systems, FMF is cheaper than ESR but I got more overall noticable power with the ESR. Dont think you need to worry about the head yet. Do you ride in extemely hot temps? If you want to bump up compression you can run a cr250 head gasket, much cheaper than a cool head. You can run race fuel but you want a higher compression motor to take advantage of the higher octane otherwise you dont gain much.

most basic upgrades that will wake your 250r up is this,

Upgrade exhaust
Install better reeds or a rad valve
Upgrade to 38mm carb
upgrade to a uni or K&N Air Filter

that alone will wake up your R without tearing into the motor

Tyler

[gomer202]

Where do you get ESR pipes tried too find one but couldn't

[dcreel]

Where do you get ESR pipes tried too find one but couldn't

http://www.eddie-sanders-racing.com/Default.asp

[lightemup01]

i ride in mostly 80-90 degree weather and some winter riding. i want to do a fmf exhaust and just the cheapest stuff to get it running better where can i get that thinner head gasket someone mentioned?

[lightemup01]

i do mostly flat groung riding in fields and some trails.

[ceaserthethird]

Cheapest mods aren't the Best :(

Start with check your compression, report back !

[lightemup01]

compression is near 175
where can i get a rad valve and cr250 gasket. i read some other forums and they said it will bump compression to around 210. also someone said i could take the middle stock gasket out?

[ceaserthethird]

You'll need to run 110 octane race fuel, anything over 200 PSI.

I'll check see if i have 1

[RIDE-RED 250r]

What are you wanting to do with your 250r? Racing, duning, trail riding? With pipes you have a few options. One that gets a lot of recommendations is the complete ESR exhaust. It a good overall exhaust and works great with slightly moded R's. Another is FMF. I have ran both systems, FMF is cheaper than ESR but I got more overall noticable power with the ESR. Dont think you need to worry about the head yet. Do you ride in extemely hot temps? If you want to bump up compression you can run a cr250 head gasket, much cheaper than a cool head. You can run race fuel but you want a higher compression motor to take advantage of the higher octane otherwise you dont gain much.

most basic upgrades that will wake your 250r up is this,

Upgrade exhaust
Install better reeds or a rad valve
Upgrade to 38mm carb
upgrade to a uni or K&N Air Filter

that alone will wake up your R without tearing into the motor

Tyler


Just to clarify...You wont gain anything at all. In fact, if you arent running high enough compression to properly burn higher octane fuel you will actually lose power/performance. The trick is to run as low octane fuel as you can get away with without detonation for max performance. Dumping higher than necessary octane fuel into the tank to gain power/performance is an all too common misconception....

You only increase octane rating of your fuel if you have increased the compression of your engine enough to burn it. It wont harm your engine running higher than necessary octane, it just wont perform as well. (You may or may not notice a seat-of-the-pants difference depending on how much higher than necessary you are running). BUT, running lower octane than you engines minimum requirements, damage will occur.....


For a stock R, the FMF full system works pretty darned good. I have one on mine along with some other supporting intake mods. Cylinder is stock with the exception of just being bored .060 over, which really doesnt gain much at all.. But once I get around to getting it ported I may end up getting the ESR setup for it.

And I concur with previous advice on jetting. You will need to dial in your machine yourself. There is no majical 1-setup-fits-all jetting solution. If your R runs good with the stock components on it, fine tune it as-is. Then as you add intake and exhaust mods it will be much easier to take an educated guess at a starting point for each mod as you add them.

Always start rich and incrementally work your way leaner to dial it in.