Matty`s Bashan Streetfighter Quad

[Oddball Matt]

AAAAAAAAARGHHHH!!!!!¡!!!1!!!!

This blasted contraption is SERIOUSLY messing with my zen!!! No matter what I do I cannot get it to rev past five-is thousand rpm!!! Maybe it's the jetting, swapped jetting, did absolutely nothing. Maybe it's the pod filter, removed the filter, did absolutely nothing. Maybe it's the carb, shelled out on a second brand new OEM carb, still absolutely nothing!!! No matter what I do the symptoms remain exactly the same, starts right away, idles like a champ but when I give it the beans it goes rrrapapapapa til 5k rpm and fluctuates up and down in that area. The only things I can think of anymore are; either it's electrical BUT: wiring harness brand new, CDI brand new, coil brand frikken new! OR the homemade exhaust is not flowing enough thus resulting in an incomplete flush cycle at revs. Guess the next thing is to reassemble the front suspension partly using old parts to wheel the thing out and see if it revs with first only the front part of the exhaust and then completely without it. If that does it, gonna order a new poop tube and be done with it. I haven't checked the valve clearances but since it starts right away and doesn't knock they should be good right? AFAIK valve lash cannot prevent the engine from revving.

Another thing is the company I've been waiting the rear brake parts from. I contacted them at 3.6. if they'd kindly re-send me the package and added a few more things I need, have not received a reply. I went to their website and it says there that they will be closed from 4th of june til 17th of MAY! I'm reeeeally hoping that's a typo or I'll be waiting for my parts for another YEAR!!! Starting to seem I'm gonna need to order the parts from elsewhere but the problem is these things are getting pretty rare so I need to collect parts from here there and elsewhere paying shipping fees from each part separately at the same time tying precious few resources into parts I've already paid for, and then try to get the original purchase refunded once they eventually open again.

Completely DONE with rebuilding this thing, I wanna RIDE!!!

[Oddball Matt]

Just pulled the plug to confirm what I was already dead sure about. I cannot post a picture as my allowed server space is currently at capacity so need to clean up there but I can tell you in my years I have never pulled a plug that black and sooty off a four stroke engine so based on that I`d say if that`s running lean then I`m the sultan of Brunei.

The next question is WHY since I`m running an OEM equivalent carb?!?!?!

[Darth Racer]

I think they do that to get around emissions on exports. Think its why all the adjustments are plugged up too.


Friggin eh... I miss the old style gas cans... I spill way more fuel with the spill proof ones then the old style spouts.... recently just stopped using the spill proof spouts all together and just straight dump it in from the can.

[Weldangrind]

Save me from reading all of the older posts; what jetting are you running now? Where is the clip? What is the pilot mixture screw set at?

[Weldangrind]

BTW, set the valves. It never hurts.

[Oddball Matt]

Originally Posted by Weldangrind

Save me from reading all of the older posts; what jetting are you running now? Where is the clip? What is the pilot mixture screw set at?

The honest truth is I do not know since the good people at Cheap China Crap Copy Company didn't see the need to stamp their jets. Based on what I've found on internet 105/35 but not sure. Clip at middle, mixture two out.

[franque]

I would guess that both are on the small size. What does the plug look like? Does it rev past 5k rpm, but not under load, and if not, does it act like it's misfiring?

[Oddball Matt]

As stated the plug is black and sooty. It revs to 5 ish k rpm at about half throttle, anything over that it feels like it's either misfiring or just drowning on excess petrol. The exhaust fumes reek of gasoline. Same symptoms when trying to ride (albeit haven't ridden more than 100m back and forth on our home street as I currently have no brakes)

[franque]

I'd see if the cat is plugged. That'd be my guess.

[Oddball Matt]

I pieced out the exhaust when I rerouted it, I had a good look through the cat and it seemed unobstructed. When I get home from work gonna try running it first without the muffler then without the whole exhaust, if that doesn't help gonna order #30 and #25 pilots for the Keihin pumpy and fit that back on.

[SilverBullet51]

Is it possible you got a bad cdi, even new they aren't always perfect. If you're not getting good enough spark, it may not be burning all the fuel you're pumping in.

[Oddball Matt]

Anything`s possible at this point but a whole bunch of symptoms point to the mixture being way too rich:

-sooty plug

-hesitating coming off idle

-misfire/bogging past half throttle

-idle mixture screw does next to nothing. Fully closed the engine dies, other than that setting has little effect

-exhaust fumes reek of petrol

Based on my studies of late ALL of these symptoms can be explained by a too big pilot jet, and remedied by fitting in a smaller one.

the kids made sure I never made it to the garage to try running the quad without the exhaust but based on my findings so far I`m fairly certain the answer here is a smaller pilot jet, which I will be ordering once I send this post. Results to be reported come next weekend.

[JerryHawk250]

From looking at your pictures it looks like the carb has a good lean to it. Possible the float may need a little adjustment. I recently was having issue tuning my carb because it was running super rich at idle. Turns out the float was set to high.

[Oddball Matt]

Has to be a picture thing as it actually sits fairly straight. After about an hour of interneting the smallest N424-21 pilot jet I could find locally was a #30 so ordered one of those, if that doesn`t help gotta dig into the exhaust side to see if the problem lies there after all. If the jet doesn`t help gonna get deep into the float level too but two differen carbs have now given me the exact same problems so I`m betting it`s either jetting or exhaust

EDIT: went to check, OK it actually DOES lean forward. Note taken, will investgate.

[Oddball Matt]

Hey guys sorry no pictures this time as my phone decided, completely without asking me (once again) to switch the picture size from 1mp to 16mp and I just can`t be arsed to go through the pain of resizing every pic...

Here`s what`s happened since the last time:

-I made a jig to hold the 30mm "Keihin" pumpy at a 13 degree forward lean
-I measured the float level and discovered it to be too high
-I adjusted the float level lower
-I reassembed the quad only to discover it had no effect to the running issue
-I took the ebay pod filter under close examination (read: tore it apart)
-I discovered that for some reason the passage from the filter element gets choked to 27mm before the carb (no small wonder it was going SCHOOOP at WOT)
-I then crushed said pod filter with a hydraulic press.
-I adjusted the carb to the best of my ability, it`s still no Ferrari but it`s definitely revving higher without a filter
-I ordered a new rear brake disc, pads and a front balljoint from France

Still do do:

-Straighten the rear axel
-Order a set of balljoint sleeves from ebay (seems to be the only place that has the correct size)
-Adjust valve lash (if only I`d have a measure to adjust them to)
-Find somewhere I can order a vacuum hose nipple for the emission valve to be drilled onto the carb boot
-Take it through inspection
-RIDE!