gg250f loss of power question

F

forgiven

New member
OK here is the deal

I have a 2011 GasGas 250f which is an enduro with a 2006 wr250f motor. It doesn't have a grey wire or the other restriction stuff. I bought it used and seemed to be low on power. I put an 06yz250f piston in and no change, and the old one was fine, put in yz exhaust cam very little change. Megabomb header and 4.1 slipon and NOTHING like my other bikes.

I have a 2006 yz250f with a flywheel weight which is a beast. I have a 2013 yz250f which is also a beast. Both are stock minus an exhaust on the 2006 but the 2013 is completely stock.

Any ideas where to look. It does ok on level ground but under a load like a hill it shows its lack of power. Air filter is clean, oil is new. I am at an absolute loss. IF I could get electric start and power similiar to my 06 yzf this might be the best bike ever made by man so please help.
 
Head - Valve clearances/sealing
CDI - No idea how you'd check it short of swapping it for another. Is it the same as the ones on the Yamahas? Maybe..

Have you done a leak down test on it at any point?

Is it possible that the engines making power but not getting it to the wheels? ie slipping clutch/heavy rear tyre & chain/flywheel mass?

Whats the tune like? Are you running the same needle/jet combo across all 3 bikes?
 
Had the valves shimmed up with the new piston. Haven't done a leak down check though. I don't have any clue on the jetting mostly because there is a quick shot on there and don't know much about them.

I would assume it is a wr cdi but I don't know that. Will have to check before I try. It would be nice to put a yz250f one in but I am sure I am not that lucky.

Good stuff. I have to unload today from my 4 day Missouri trip and hopefully start later today.
 
Last edited:
He states it doesn't have any restrictions on it. It would be easy to tell if there is a throttle limiter on the GG's engine just by looking at the throttle cable at the carb, or peering into the back of the carb to watch the slide open.

My thought is to check the airbox on the GG. Is it restricting airflow some way when compared to the the YZ box? I would have said the silencer but you changed that. My experience with WR250's is that the stock silencer cuts down on top end power. That got me thinking what else is cutting off airflow. I'd try running it without it's seat and/or comparing the jet size between your '06 Yamaha and the GG.
 
It certainly looks like I need to drop the subframe to get it out. The shock at very least. Am I seeing this correctly?
 
Flip the subframe up. It'll pull the boot off the carb (once loosened).

Good points re air intake/restriction that could make some difference. However lack of power under load screms lean to me.
 
OK...sent the carb off to zip ty racing to do their mods.

They clean them put in an emulsion tube and some other minimal things.

They put my pilot from a 42 to a 45, and left my main at 180. Changed the squirter adjustment by the throttle cables from 2 to 3 turns. They cleaned things but the jets were older and not shiny smooth, more on that later.

To remove the carb I took off the tank and then flipped the subframe. Oh my what a pain in the Husqvarna. Was a great opportunity to reroute a bunch of stuff to get it off the engine which makes me happy.

When I sent it off there was no bog whatsoever but a real lack of power. When coming back it had the typical YZ bog. Now frustrated I started playing with the squirter adjustment and fuel screw. I replaced the main with a 178 since it was brand new and I have seen cleaned out older jets just not perform like the shiney newer ones even smaller ones. I put the squirter back to 2 turns, did the oring mod while there, and finally landed from 2 turn out on the fuel screw to 3.75 and I have to try real hard to get it to bog. It runs MUCH better but not quite at the YZ level. Enough to get my wife in trouble that is for sure.

Soooo my real question is if I went to a 48 on the pilot should I be able to close down on the fuel screw with no adverse effects to the bog? The other idea is to go 180 or 182 on the main and I should be able to close down on the fuel screw some. I does run real good up top so I think I am supposed to go with the bigger pilot. Just checking since changing things is so very hard. Technically a bigger pilot should give me more off idle torque long as I am not too rich...correct?

Thanks

Steve

Obviously it was sooo gummed up in there it just couldn't get the power out of the motor I am guessing.

Additionally I don't mind being a little lean on top now since it won't be ridden until it is warmer, and my wife will spend zero time at WOT...only when I ride it.
 
I would make sure your cam timing is set for yz specs and not wr specs.
On the jetting I would go with the 48 pilot, that should get your fuel screw back down to the 1-3 turns out area. If you have it jetted good but still have a bog when you wack the throttle I would change your leak down jet. Remember this is the opposite of what you would normally think of on jetting. If you want it to shoot more fuel you have to install a smaller jet and if you want it to shoot less fuel you install a larger jet.
 
I have read where some have changed the leakdown jet to a 40 with good success. Due to my unfamiliarity with the leakdown jet I have stayed away. I tried to do some looking but didn't find much. Any insight would be greatly appreciated.
 
What rosco said.

Start with the larger pilot and see how you go. The main thing I've noticed on the 4 strokes is that when the pilot is rich they can be a right pain in the anoos to start when hot. I assume they have the hot start lever like yamaha. Ideally I try to get the bike to fire hot without the hotstart, and save it for the flooded moments.

Loads of info on how to remove the yamaha bog. Leak jets and AP squirt timing. Get to know them well and take the time to set it up properly. You'll be rewarded.
 
lol...I actually have a Quickshot 3 on this which is an adjustable leak jet.

Sometimes my ignorance makes me laugh and cry at the same time.
 
OK

Now that I call Boyesen and now understand how the quickshot 3 is actually working (didn't have the instructions because it came with the bike) I set it to a leak jet of 50-58 I am guessing.

Put the squirter back at 2.5 turns out, and I will say it runs pretty dang good. I know the neighbors have to be hating me about this time.

I would have to ride it back to back with the YZ250f but it is safe to say it will too much for the wife now when she grabs a handful of throttle. It will however, make a great back up bike for me once I take that Kouba link out of the back linkage. Thanks for the help and suggestions everyone.
 
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