gregrob

Not yet Jon. Might tear it down this week but I'm pretty busy with work. Might have to wait til the wknd or after I get back from chi town

QUOTE (C&B @ Jun 21 2009, 01:41 PM) <{POST_SNAPBACK}> mine was bad crank seal/bearing on the right side. Are you running stock bearings and helical gears (SPELL??). Same set up not alky though. Do a leak down man, then youll know for sure. If not, Id say detonation as mentioned before. Thanks, I'm suspecting my crank seal too. This was all new from HJR last year, but still could be bad I guess. Stock bearings but straight cut gears.

I would think too much advance would hurt both cylinders. Of course one could go before the other. Besides +8 is totally reasonable on a methanol bike, especially at my elevation. What makes you think CDI? Wouldn't that affect both cylinders as well. Not saying it couldn't be, I'm just curious to hear your reasoning.

It's on methanol. Don't get much higher octane than that. and yes you do add fuel when you add more timing. It's always best to go rich, then work your way down. This wasn't a jetting/timing combo issue as I stated in the opening post. The left cylinder is fine. Something happened on the right to cause it to go lean, start detonating and torch the piston. I just need to find out what.

Good idea. Yes on pingel and gutted cap. Only thing I dont have is billet bowls because I haven't found any for these smaller mikunis.

Different bike dude. Loco wants me to blow up the fast engine. I'll say this nicely the first time. Please offer constructive input or don't post in my threads.

Uhhh, I thought the slingshot was supposed to fit under a stock cover. Isn't that one of the main points of the thing? Bump for a nice lockup. If I had the extra cash this would be gone

Well we were out beating on my duner today and the right cylinder let go. Melted the ground strap and electrode completely off the plug and starting melting the threads. That cylinder has ZERO compression, will not even make the needle on the comp tester flicker... lol Dont know what happened but I will be inspecting everything as I tear it apart for possible causes. It was only the right side. The left side still has good compression, and the plug looked great when we took it out. I'm starting to wonder about this thing because every single time I have had a problem where I've been too lean, it's been on the right hand cylinder. Like maybe there is an air leak at the cases, or crank seal or something. Definitely going to be watching that very closely as it goes back together. Only changes to the bike from last wknd were I advanced the timing from +4 to +8 and opened the powerjets 2 turns to compensate. The bike was beastly in the bottom/mid range but felt like it bogged just a tad on top, so I closed the powerjets 1 turn, and made a few more runs. It pulled clean all the way through the powerband, until this happened. Only problem I have with blaming jetting, or timing is the fact that the left cylinder is cherry. No problems at all, plug looked great, still has good compression, etc. Bike is HJR dune ported 4mil with 19cc domes and this happened at about 8500ft elevation, so the compression was extremely low for methanol lol... Running 35.5 mikunis with a 55pilot and .103 mains. Bike has been running like this for a long time and hasn't had a problem until now, so either something happened to cause a big air leak and pull that cylinder lean, or just the RIGHT side didn't like the new jetting/timing combo... Other option is that the right bowl got sucked dry. It was in 6th at WOT when this happened. Damn it was running hard before it let go. I just gotta get back to that point and get it to live and we'll be good. Still had fun mobbin the hill climbs with Rippen and crew on the other bike though. Any ideas are appreciated. I'll be in with neat-o carnage pics later.

I have around $3,400 in mods on my duner and I would bet it would be in the range you're talking if you could keep it down. Ported stock cylinders are gonna be your best bet, cost wise. That and don't be afraid to look for good used parts. I shot a little over 1500 towards Kevin for porting, pistons, crank, etc, etc, already had the head. Just over 200 for the carbs on ebay. Just over 200 for the front shocks 275 for the swingarm It can be done. These guys make a good point though, dont blow your whole budget on the engine only. Even a mild running 4mil will make your life miserable on a stock swinger lol. Been there done that.

What size are the tires and wheels

Ill trade you for PJ's setup on gas. Theyre good clean carbs that run awesome. Just switching this engine from race gas to meth. Let me know

A well setup 4mil will do the trick. I ran with the hansen performance boys with my fast ported stock cyl 4mil. They placed very high at fourstrokewars that year, so needless to say they were among the fastest 450's out there. They had a yfz, 450R, and a Raptor. EXTREMELY stripped down and lightened frame. tiny a arms, spindle mts, no plastic, etc etc. Running insane compression, overrides, every trick in the book and my 4mil worked most of them over. Their fully built raptor was a little faster than me out of the hole but I would catch him on the hill. Only Honda 450 I worried about was the one with the turbo. Damn that thing was fast, but I was still really close to him. Put my engine in a lightweight frame with a light rider and it would have been game over, easy. I raced another guy down in CO with a SUPER nice yfz, custom lightened frame, big 500+cc stroker motor, he was a tiny little guy and with his bike on motor it wasn't even close. When he was spraying the shit out of it, it was a little closer, but I was still getting him by several bike lengths at the end of the run...

Increase your main jet 2 sizes and do a plug chop. That should get you close.

1) do a compression check if they are the same or very close 2) check / clean carbs, make sure you don't have a plugged jet, make sure needles are set the same, verify slides are both opening all the way up. report back

I doubt it is the water pump. Could be the clutch basket coming loose if it's on the right side of the engine. When the flywheel comes loose it sounds like that as well... but that's on the left. Does it go away with rpm, or get worse? Is there also a vibration present? Pull the clutch cover off and do a good visual inspection before you keep riding it and damage something further.

The manual is wrong if that's what it says... the spec is 22ft lbs for ALL the shock mounting bolts, and dogbone bolts. The spec for the large bolt that the swingarm pivots on, (technical name: pivot shaft) is 61ft lbs

BTW I'm at 6,000ft elevation

Sweet dude! I have an aggressive dune port that is customized for my weight, elevation, etc from Kevin and it is, in your words, AMAZING!

Planning on drilling the dumps to .116 and starting w a .116 main and 60-65 Pilots That's how the PJ's on my FAST motor were setup. Those carbs are gone but I have another gas set of PJ's to setup and the bike ran hard with that jetting. What needles would you guys recommend. Thinking of EGN or EGQ Any other tips, cautions, or advice you have is appreciated. Done a lot jetting and making my own jets on my other duner but never drilled a set of dumps and dont wanna make a mistake on the PJ's as they dont have removable dumps, as we all know. Thanks Greg

I have a 2-5 WCR full override and I am looking for either a 1-5 duneable or a 1-4 m5 m6 duneable. Could add a little cash on the deal if necessary. Shifts great, just looking to make this engine more dune friendly. thanks, Greg

Is the override full or duneable?

.003" actually. But whos counting

That is all

Got a +10 chrome if youre interested in a trade bump for a good seller

1500? WTF