Bog/hesition fixed but it's back...

[Soup-n-sandwich]

Hi guys,

I have a new 20024 X-Pro Storm 150 DLX. With the stock generic carb it was running lean. Since the jets are not standard and use an adapter and the fact that the air mixture screw is buried and facing down with no possibility of adjusting it when it's on the bike and the bike never idled that great... so I bought a Nibbi PE26 which is a 26mm replacement for the 27mm no name stock carb. I swapped it out and it ran MUCH better than with the stock carb. I had checked the plug after running it for a bit and it was quite black with lots of carbon so I leaned it out a bit. I did this three times as I progressively went down in jet size. On the third time I reassembled everything and rode it. When cracking the throttle quickly it would stall or come very close to stalling. Prior to this last jet change it ran great but a little rich. I later found that the intake plastic spacer that fits between the carb and the intake tube of the engine was cracked providing a nice air leak. I replace this spacer and the problem went away. Then out of the blue I was riding aggressively and it was bogging big time when cracking the throttle out of a corner (and everywhere else). So I suspected that maybe the new spacer had a crack in it or there was a leak in the same area. Nope. Although the symptoms were exactly the same as before the fix is not.

I did try going with the same jetting I did before when it ran great...no change.

The stock carb used a pilot jet of 45 and a main of 95 but since this was lean when I installed the Nibbi carb I changed the jetting. The pilot was a 40 and the main was a 110. It did run pretty good but like I said, it was a bit rich with this jetting.





Thanks
Chris

[J4Fun]

Hi Chris, welcome! Just wanted to know are your valves properly adjusted? Read your post and with my bike the same as yours and totally stock doesn’t have that problem. In fact I just started it a few minutes ago to make sure. It can’t be said enough adjust valves first then go from there! I’m here in North central FL BTW so low elevation like yours. My thoughts…

[Soup-n-sandwich]

Originally Posted by J4Fun

Hi Chris, welcome! Just wanted to know are your valves properly adjusted? Read your post and with my bike the same as yours and totally stock doesn’t have that problem. In fact I just started it a few minutes ago to make sure. It can’t be said enough adjust valves first then go from there! I’m here in North central FL BTW so low elevation like yours. My thoughts…

Hey bud, Thanks for you welcome! I haven't checked the valves but I did fix the issue. It was a compound problem. Because I was thinking at first that it was a jetting issue, mostly because I was at a loss as to what was going on I tried many jetting changes then I found that the Nibbi carb when installing it on the bike (X-Pro Storm 150) I noticed that the o-ring was a little exposed. I then realized that when the carb is bolt on to the engine's intake tube the carb naturally (due to gravity) will be a little too low when matched up to the plastic intake spacer. So when bolting on the Nibbi carb it's important to pull the carb up and push the spacer down, then tighten it up. This makes a good seal. If you just slap it on there it's possible there will be a little air leak because the alignment isn't quite right. After that I tried the bike...but it was still hesitating/bogging under heavy throttle. I went to go eat dinner and was thinking about it. I remembered that I never revisited the jetting. I recalled that I was going lean because the spark plug was showing it a bit rich. I ended up having a 40 pilot and a 90 or 95 main. WAY too lean for the main. I swapped up the pilot with a 35 and installed a 120 main and the problem more or less went away. I say more or less because it's not perfect.


I still have to tweak it a bit. I had saw on some forum that a guy with the exact same carb PE26 had the same issue on a Yamaha 125...can't recall the model. But he too said that 35 pilot and 120 main worked for him.



I'm working on suspension now. This bike was suppose to be a messin' around bike. I wasn't suppose to be taking this bike this seriously. I have a race bike for that but the race bike is a huge restoration project as well as a tribute project so it's in the work but will be a high profile bike when it's done. Anyway, I'm about 135lbs 5' 6" tall. I've been riding full size bikes since I was 96lbs at 14 years old...so I had no intention on doing anything with this bike other than messin around on the farm and to get around the farm where I work and live. But I should know myself better than that! I started riding it aggressively and learned a few things. One, if I don't get the suspension working for me I'm going to need to hire a full-time dentist to replace the fillings that are getting rattled out of my skull because this suspension is downright scary. The bike is all over the place..major deflection off of everything. Yesterday I took it for the first time in typical East Coast woods. The trail had a lot of embedded rocks and roots. Holy crap it was brutal! I've never ridden a bike that deflects so badly. I was only going like 7 to 10MPH coming down a sight decline and was going to sneak between a bolder and a tree...the rear end hit a rock and deflected (hoped) to the right so badly that it almost made me hit the tree. I changed the oil to ATF in the fork. This did speed up the dampening...but not enough. So I'm going to have to open the fork up to see if I can open up the valving. The shock was even worse than the fork. I was going to rip that apart too but found that DNM makes a 320mm shock with adjust rebound but only offers it with a 1000lbs spring. I thought that was way more than the stock spring but it turns out it's the same as the stock spring. Since the bike doesn't have any suspension linkage I was surprised to realize that the 1000lbs spring rate is actually correct for this bike IF you weigh 145 to 170lbs...but it's too stiff for me. The free sag is about right but the rider sag isn't enough....long story short - I have to grind the spring because DNM doesn't make a softer spring for this shock. Holy crap this is turning into a real project that I didn't want. I never intended to dive in to this bike this deep. BUT I know how it should ride and it's not at all the way it should be.

[Mumen Rider]

Originally Posted by Soup-n-sandwich

I haven't checked the valves but I did fix the issue. It was a compound problem.

You should really set the valve lash correctly, from the factory they are tight as can be.

[Soup-n-sandwich]

Originally Posted by Mumen Rider

You should really set the valve lash correctly, from the factory they are tight as can be.

I'll take a look at the valves too. I did get it running very well now. I ended up using a 40 pilot and a 120 main with the air screw out about 2 turns and the needle in the middle position.