I have an almost stock 86 atc 250r that has been giving me nothing but trouble. At first it was running really good it had all kinds of power through the gears untill you hit 6th as soon as you let the clutch out it falls on its face. I asked the honda shop where I am from what I could do about this. They told me to go up a few sizes on the main jet because it sounds like I was running lean on top end. I had a 138 so I went to a 140 then went to do some plug chops and got upset it wouldn't even hit the powerband in any gear. It was running rich so I tried to lean it out with the needle valve that didn't work so I tried it with the airbox lid off It ran slightly lean and massive lack of power. So I bought a new UNI airfilter and a set of Boyesen dual stage replacement reeds. No luck still after all that and alot of jetting and plug chops so I got a reed spacer. It helped alot but still not right. So I did a compression test I got between 155-160lbs. I was told that was good so I checked the gearing 13 in the front 39 in the back. I heard that was the combination used by people who ride in the sand dunes for quick takeoffs. Then I started to wonder it my tires could be robbing my power. I have Realtor RT paddle tires the width is 12" and hight is 22". I would appriciate some expert advice to put me back where I belong in front. I hope to hear from someone soon my buddie just got a 2005 TRX 450R that is in need of a good old three wheeled beat down. Please help.

 

What other mods do you have? What pipe are you running? My buddies 84 did the same thing, we changed the packing in the silencer and cleaned the carb real good and it helped alot. How much over stock is the cylinder size? When was the last time the top end was rebuilt? You may need new rings. Just a few thoughts.

 

Hey R Fan man, what does the plug look like when you chop it? White, light brown, chocolate brown, dark brown? Also, if it is not running correctly you need to find the problem before you keep adding mod's because if it is a lean problem you will seize it. To me, if it is not a mix problem it does soud like a dirty card or old fuel problem. Did this problem just happen or has it been on going?

 

I dont know how long ago the top end was rebuilt or the size. I thought that there was a DG silencer on it but after to many hour on DG web sites trying to find one that was the same shape or sticker on it I brought it to the car was and sprayed every thing really good the sticker came off and there was the the wrighting that is on the stock one. After taking the silencer off I found it to be a little on the heavy side (10 pounds) and no packing on the sparkerester. Do you think that she could be plugged. The compression is 155-160lbs think I should rebuild or just put a head gasket from an 89 cr 250? I as so come to the conclusion that NGK plugs are junk every time I run them they go to crap after 2 or 3 rides they look to be burnning just fine just dont spark every time it should. I went with a champion I beleive it was a RC12 never had a problem starting or foulling. The plug color is the about the color of a brown paper bag. Any ideas of a cheep but decent kind of tires and size to buy?

 

The silencer shouldn't weigh more than a pound or 2. If it weighs 10 than I would definately say it is clogged up pretty good. That will kill an engine of power. Take some pics of it and post them. As far as the compression goes, 155-160 is good for a stock engine. Clean out or replace your silencer then see how she runs. It should be a huge difference. I have run NGK plugs in all of my bikes since I started riding 26 years ago and have never had a problem with them. Let us know what happens.

 

I got out riding today and this time I had no problems with it running. But I was still lacking topend and a little weak through out the powerband. My dad just gave me a set of rear tires today I hope they work a little better than the ones I have. I know the Realtor R/t Paddle tires that I have on there now are way to heavy. I got some weird type I think they were called H trac or something like that. The size is 11-9-22 I would say that they weigh almost 1/2 as much as the other ones. Do you think I should go smaller? So if I put the lighter tires and a new silencer on do you think it will go in 6th gear(no power). I cant clean the silencer some one welded the baffel in the end. Should feel a powerband in every gear? What is a decent silencer?

 

There are alot of good silencers out there. DG and ESR make good ones.Try running it without the silencer and see if you notice a difference. If not then maybe your pipe is all clogged up. Check at the exhaust flange, they can get some really heavy build up. If none of that cahges things you will need help from someone more knowledgable than me. There are alot of great people here willing to help. I'm not to sure about tires, but I do know the tire height does change your gearing. I run Sand Sharks on mine. You can see them in my photos. Please don't laugh at my bike. It is a work in progress. I get it back this week I hope. I have a new ESR ATC5 pipe and silncer, a new cooler rack/grab bar and a new front fender. Not to mention the engine just got rebuilt.[img]i/expressions/face-icon-small-happy.gif[/img]

 

I got her running nice. I found a used silencer for a banshee. It is an Answer type 2 I believe. I figure since a banshee is a 350cc two lunger that the silencer might have to much back pressure so I took out the packing and cleaned the baffle. I also got some other tires on it. I am still having a little problem with foulling plugs. It only seems to happen when it sits for more than a minute at an idle. Do you think that I should drop down a size or two on the pilot jet? How hard is it to change the shaft that the shifter attaches to? I checked out your photos didn't laugh I never said mine is pretty. Apperance isn't everything. Well I kind of raced my buddy with the 2005 trx 450r. I took him in 5th just hit powerband and had to let off because it started to feel like it was going to lose control. When we stopped I asked him if he had it maxed and he said kind of. I think he was just embaressed because I had him by a half a block and still had another gear when I let off. The reason I believe he had it maxed is because we were on a two car gravel road and he was keeping almost side by side untill 5th. What your guess?

 

No offence to you or your trike, but I think the rider on the 2005 trx 450r, was scared of it! You have a fast trike there, but not a half a block fast!!!!! expecially in only 5th gear