blowit

You will NOT experience engine damage/failure or any thing close by using alcohol products in gasoline. The government mandated it so you will see it at nearly all pumps by now. 10% Ethanol will do nothing but good things for the engine BUT may require slightly richer jetting. Alcohols will make an engine run cooler but there is less energy lb for lb when compared to gasoline. That does NOT mean slower, than means you will use MORE fuel. The reasons Ethanol can cause problems is due to it being exposed to plastic and rubber parts in the fuel system. It may or may not cause problems depending on your system. We have yet to have one person have issues. We are even running on E85 which approx 85% Ethanol without fuel system problems. Also, due to the fact of being a two stroke, the oil in the fuel helps to protect rubberized parts in the fuel system and engine. I would NOT be concerned about the alky BUT it is ALWAYS advisable to test your premix oil in the fuel in a test jar and make sure it blends well and does not separate. Many oils do not want to blend well with straight alky but do just fine with E10 gasolines. Brandon

Top of port to top of deck on all ports and discover if xfers and exhaust fully open at BDC. may also want to take a few pics to see if we can spot anything troublesome. The pistons are in the right direction, right? Windows in the intake side? That will make for a turd in a punch bowl if not. Brandon

I would say it is time to pull the head and do some measuring if nothing else can be decided. Also, sometimes a lean motor will run well but not strong if that makes sense. Brandon

Sounds like you have done enough homework and problem may lie in the porting, pipe combo. Give more specifics on the engine. Does not sound like you have electrics issues. B

PJ idle adjust is part of the choke knob. You will turn the choke knob to adjust the idle. Adjusting carb sync without the proper tools is not recommended but you can get very close by removing the air filter system and adjusting the upper cable tension so both slides pickup at the same time when you hit the throttle. Listen carefully when the slides set down. There should be one click if they set down in unison, two if they are out of sync. Brandon

I do not see any concerns with 160psi comp with the +4 timing and 91oct fuel. I would not sweat it, especially with the avg ambient temp. Brandon

I think one better look at the properties of Nitro. before adding to any engine. The burn rate, octane, and btu/gal are key specs to tuning this fuel. We have used up to 20% in banshees but detonation is very hard to hold back because of the properties of the fuel. Best of luck shooting from the hip with this fuel. The fuel can be hard on rods and can cause piston fractures. Piston anodize or coatings are preferred with this fuel. Brandon

The TORS system does not work like that and will kill both cylinders. If the bike will idle with choke, you need to revisit the carbs and specifically the pilots. We used to get 5 bikes a week that were "clean" but the things that counted were clogged. If you want to bypass the TORS, just unplug it. Plugs on the carb tops and the black box located just above the LH cylinder on the frame rail. You may also want to verify that the choke xover tube is in place and not cracked and your slides are synced properly. Sure sounds like a tuning, sync problem, or coil wire/plug cap problem from here. One side firing is just not TORS induced. Brandon

Pilot jets need cleaned. Brandon

Replace plug caps and plugs. Caps can be easily tested but easier for most to just replace. Remember to cut off about .25in of plug wire to ensure good contact with the new ones. Use LUBE on the caps they they thread up nice and buy the watercraft NGK ones. Brandon

That pink sure is purdy.

Slides in backwards. Please make sure chamfer on bottom of slides is on the filter side.

um, where did the sand come from??? Did you have funk in your pipes that got sucked back in? Was it in the lower end hanging? We have seen several motors grenade from a lack of cleaning the pipes out after a motor failure. I will bet there is damage from that sand encounter. I would start at the air filter and work forward. Yuu may also have detonation damage on the piston which will feel like sand. Depending on how much was there, I might pull the head and take a peek. Only takes one grain to ruin a crank. How was the motor built? Bottom up? Top end? Brandon

The intake is only a small part of a port job. You would have to remove the cylinders to get all the data needed to figure out what you have. If you do have a quality PJ that matches your pipes, you are probably fighting some jetting issues or have not complimented the porting with compression and timing mods. B

Drag race specs or at least timings. sounds like it is not well matched if nothing is done to the intake. After looking at that pic, they seem to be cut for speed, not comfort. We would probably seek to do more work in the intake but it looks pretty good so far. Brandon

LRD was doing it with a PWK 28mm tapered to 30mm. They do not perform any better than a 29mm carb. Simply that even with an increase in velocity after the carb, the air charge will still hit a brick wall (the reeds) and null any effects. Brandon

We feel the taper bore was a fad and that is about it. The reason mostly for the venturi on the back of the carb is not for velocity, but for pressure drop that allows a low pressure cell over the jets to allow better fuel flow. Brandon

Things that we have seen in the shop are powder coated frames and poor ground terminations. All components need to have a good ground reference including engine to chassis. This is VERY common for pained frames. Stator grounds to motor, Coil grounds to chassis, if it cannot get there, it will arc through you to try and get there. Easiest way to find this is put a multi meter on ground point of motor and one of the ignition mount bolts. That would ring out with zero ohms. Any resistance at all will be a problem. Brandon

Remind me not to port your engine. You ever make a mistake? I sure as hell do not fly that. People screw things up at their job every day but want to give a machine shop the third degree over someone else making a mistake. People make mistakes. I will guarantee you, you show up at my place with a crow bar and you will meet half way with something with a bit more velocity to it. NOT the way to deal with your problem and NOT good advice. I met a similar guy months ago and his "health" is still in question over it. Recommending trashing someones business is NOT the way to handle a business matter. Brandon

You need to post up some pics of that cylinder and the port edges. A reputable build would know what caused this. I am not going to point fault but more info could weigh your situation. I am leaning towards a ring hanging in a port. If you can map the ports or show some good pics, that would help. Brandon

Remember these are Hotcams. That mod was is the hot setup for OEM cams, but I have not heard of it for a Hotcam.

Hoping someone here has a data sheet for this by chance. We have "misplaced' our install guide for Hotcams for the YFZ. I cannot remember but something is different about the alignment from the OEM cams. I looked at it from the stock settings and it is opening the exhaust way off. Anyone happen to have an install guide for these. We are trying to get a motor completed this evening. If anyone knows of a database for this tech info, that might help too. Thanks Brandon

This pro, for one, hardly ever uses a timing wheel. They are great for 4 pokes when checking advance, retard, and total open. For two strokes, math is best but you can definitely get there with a wheel. Mine is by Motion Pro. For a piston stop, we do not use one at all. We would use a special adapted vertical dial indicator dropped in the plug hole. Highest measurement read on the indicator will true TDC. Kudos for doing it the right way! You will be happy in the end and even if your motor does not make 100hp, you will know where you are and how to make it better. Brandon

If you turn those paddles around the right way, it will feel like you just got a port job!!

Not real sure what the correlation is between the engine output and the torque on the clutch basket but no, the clutch basket bolt can cause bearing failures if assembled wrong but not cause trans problems. The counter sprocket however, can cause problems. brandon