What are the symptoms of needing valve adjustment.

[Darin]

My new CRF150RB seems to be a bit sluggish of idle. It probably has 12 hours on it, mostly 2nd gear, nothing wide open. It wasn't when I bought it. It revs ok, but that first moment of cracking the throttle doesn't hit like it did. I can't imagine the plug could cause that, could it? Has clean air filter.

How much do you suspect the Honda shop will charge to adjust/shim the valve thingies? I'm really not interested in doing it myself.

Thanks, Darin

[Woody_393]

Some symptoms are:

A lot of backfiring
Loss of power
difficulty starting
typically won't idle.
Dies when you are riding it and chop the throttle or slow down for a corner.

Adjust them yourself. It's easy.

And if you have the manual that came with your bike it should tell you the clearance and actually run you through adjusting it yourself.

[Darin]

Originally Posted by Woody_393

Some symptoms are:

A lot of backfiring
Loss of power
difficulty starting
typically won't idle.
Dies when you are riding it and chop the throttle or slow down for a corner.

Adjust them yourself. It's easy.

And if you have the manual that came with your bike it should tell you the clearance and actually run you through adjusting it yourself.

I read the manual, and saw that it does walk you through it. But my memory stinks. Is there some adjustment available before shims are needed?

Don't plugs just work or not work? Can a plug cause it to run. but poorly?

[AgentSmith]

Originally Posted by Darin

I read the manual, and saw that it does walk you through it. But my memory stinks. Is there some adjustment available before shims are needed?

Don't plugs just work or not work? Can a plug cause it to run. but poorly?

The adjustment IS the shim. They have shims from the factory. You use thinner shims as the clearance closes.

The 150R/B doesn't have the issues with valves like the bigger bikes. They are steel from the factory.

My guess is a partially blocked pilot jet.

I don't know what the shops in PA charge, out here in SoCal it would cost about $ 65 to adjust valves.

[ccnut]

I thought you were going on vacation? Wheres the pics of you busting that new monster track?.....Jerry

[Woody_393]

AgentSmith is right. The shim in the adjustment.

Yes, sparky's typically either work or they don't. I've never once had a spark plug related problem on my CRF450 or RMZ450 so I highly doubt that is the problem. It doesn't hurt to look at it though and see what it looks like and check the gap.

[Darin]

Originally Posted by ccnut

I thought you were going on vacation? Wheres the pics of you busting that new monster track?.....Jerry

Vacation is coming up. Waiting for cash in hand from equity loan to pay for RV. Also, the owner selling the RV approved any repairs that might need done. The generator runs a little rough. And then we have to give it the serious look over and test everything.

The track is built. All the jumps are shaped. I am spending about 2 hours a day hand grooming everything. I welded up a "rake" to pull behind the lawn tractor to help get rid of the tracks left by the Cat. I've ridden most of the track, but not all of it yet. Today I had about 95% of it ready to ride. The whoops still need work. They are rough, and frankly, too big for me. I'll be knocking them down a bit while smoothing them up. I can always make them bigger again later if I need to. The 40 and 50 tables are a bit scary still. I used to do this stuff all the time on my KX250. But that was years ago, before my last good crash than ended it till now. I wanted to build the track so I could grow into it and not get board right away. I still have the "step on/off" to go ride. I spent most of yesterday and today working on it. It looks good. I just didn't get the bike out today.

[ccnut]

Sounds cool Darin, Thats a big investment,Def. want to make sure all is right! Hope you have a blast! As for the track ...please post pics of your riding progression on it. I have yet to ever bust a 40 or 50' table top.....Jerry BTW I kind of hyjacked the thread....Sorry

[Darin]

Ok, the bike starts and idles fine. Just has a squeemish bark, that it didn't have at first. Revs ok though.


Finished dressing the whoops (no fun and ridable) and the step on/off today and finally rode the whole track. Being 42, and having shoved and raked for and hour and a half, I was tired before I rode. But it was a blast. The Step Off was a bit daunting at first, it's RIGHT into a turn, you almost land with the brakes on.

[Darin]

A friend that is an ex pro sport bike racer suggested that I might raise the needle, lower the clip. Could be temp an humidity? Would an air mixture screw adjustment make a difference?

[AgentSmith]

Originally Posted by Darin

A friend that is an ex pro sport bike racer suggested that I might raise the needle, lower the clip. Could be temp an humidity? Would an air mixture screw adjustment make a difference?

Before you go changing your jetting try a couple things first.

Remove pilot jet and clean it. Run a small wire through all the orifices.

If that doesn't cure it, try opening the fuel screw 1/8 to 1/4 of a turn.

If you get nothing from those, catalog your jetting and report back what your current set up is and we can help from there.

[noobish]

Originally Posted by Darin

A friend that is an ex pro sport bike racer suggested that I might raise the needle, lower the clip. Could be temp an humidity? Would an air mixture screw adjustment make a difference?

Four strokes dont have air screws, they have fuel screws and yes adjusting that with temp changes can help. I would buy an adjustable fuel screw for that bike if I was you. If the jetting was good before I dont think its the needle, it sounds like a dirty pilot jet and that is easy to get to

[Darin]

Originally Posted by noobish

it sounds like a dirty pilot jet and that is easy to get to

I had the plastic, the seat, the subframe off. Then, I saw a bunch of stuff attached to the carb I've never seen before. This is very unlike my old KX250. There are wires and tubes stuck on this thing, and very little room. My old carb, you would just unscrew the top where the throttle cable went in and pull out the slide. This is completely different.

So are you saying I cannot adjust a fuel or air screw on this? I think I need to get a clymers manual or something.

[tirebiter]

The fuel screw is on the bottom of the carb, just in front of the float bowl on the engine side.
Part # 6.


You can order adjustable fuel screws from JD jetting, I like the brass T handle unit.
[Only registered and activated users can see links. ]
It appears you have a Keihin pumper carburetor, but contact JD, see what exact needle fits.
Make sure you unscrew and remove the hot start before rotating the carb (Pt #8), it's plastic and easily broken.