I got an '86 Honda 250R three wheeler, and it runs great. I just got one problem. I got an FMF pipe on it and just finally got it jetted, but it seems to be loading up on low end not really bad but noticeable, All my riding friends say that I need a new carb, but I don't think I do need one cause it runs great everywhere else. there's a 35 slow jet, and a 152 main. Clip in the top position. If you were gonna be drag racing. You hit the throttle, stumbles and bogs for a second then takes off like a rocket. This has totally got me stumped. The are stock reeds too. I'm running MC-1 at 4.5 gallons to a bottle. I'm thinking of first buying a new needle because that solved a carbration problem on another machine I had. Any input would be appreciated.

 

GO WITH A 40 PILET JET AND DROP THEN NEEDLE DOWN ONE OR TWO. IT SOUNDS LIKE YOU ARE OUT OF FUEL AT TAKE OFF.

 

If that doesn't work, then you may be loaded up on the low end, so try going down one size from a 35 slow jet. and repositioning the needle.

 

Sounds like you are lean if you nail the throttle and it will stutter and then come one strong. If you are rich it will feal sluggish. Richy26, are you sure you want to lower the needle? This will make it even leaner. I would say raise the needle (or lower the clip) one notch.

 

I'm positive it is rich because when I pull the plug it is black and if it was sitting there idleing it wouldn't take it 15 seconds to start smoking really bad. None of the other bikes I ride with do that. I think I'm going to drop the main a bit and get a new needle. Because I think the 35 slow jet is the smallest thay make.

 

If that is the lowest they make, and i surely doubt it is, then you have other problems. maybe carb problems. call to check out the jet size situation first though. if you raise the clip on the needle it will help lean it out from just off of idle and up.

 

Would my reeds have anything to do with it? Since, they are stock ones, maybe they aren't strong anymore and aren't fully closing? Could this be the problem? What are the best reeds to get with a stock cage?

 

it could be the reeds. my '86 250R was missing real bad on top end, so i pulled the reed cage and the stock reeds were shot. i replaced them with boyesen pro series reeds, and it solved the problem. pull your reed cage and check out the reeds. if you can see light through the reed cage where the reeds should be shut, replace them.
---keep the rubber side down---

'85 Honda Odyssey 350
'86 TRX250R---stock
'87 TRX250R---too many mods to list

 

If you're still running with your jet needle in position one, you might try raising it to position three. These various jets & the parts of the band in which they function, are not set in stone; there is a certain amount of overlap. Your needle is barely opening the needle jet as it is and is lean. When you nail the throttle, the main jet finally comes into play & that's why you take off so well after stumbling for a while

 

2 strokes like a rich pilot jet. It fazes out early in the throttle position anyway, but does affect immediate throttle response from dead idle etc..

Conversly, a rich needle setting will make a bike stumble on throttle, while a rich main jet will keepo it from taking RPm well.

Net: Lower the needle (raise the clip) and see what it does. Try it 2 settings just to see if it changes much.