Hey why is there a 686 for a Raptor but not a 678 for a Bomb. I think that should be the stage 1. I slight bore, carb K&N, cams and a piston along with a pipe should be yield nice gains. And you dont have the split the cases.

 

sorry double post

 

Knutz, I was thinking the same thing when I hit the post button. Sorry!!! You would be a MAJOR exception to my rule -- You are in the business and I see you often offering "helful"sic information concerning the DS and other machines.
I wonder if Bomb ever thought of "Dirt Doo" as the natural progression on their name?? lol


Vegas, yes many of the dyno runs were on the old Trinity dyno. Unfortunately, after a hard drive failure, most of the old runs (686 and early 727's) were lost and are only a memory --except for a few printed sheets that are floating around the dunes and Yamaha. On the new dyno, I agree hp seems to be down a spot but I think it is only a fine calibration issue. Remember, anyone who has a dyno can achieve different results with the same engine. The reason has alot to do with the setup. For example, the tire type, diameter, air pressure, rim composition, location of the tire contacting the drum, amount of down force placed on the atv, temp of the engine, fuel, mixtures, etc., can all make a change. More important than those variables, the type of idler roller used when you dyno the atv can make a major difference in hp levels. Trinity tried to keep as much constant as possible. All tests on all bikes were done with the same tires, about the same down force and drum location, etc. I think that the story about the old "generous" Trinity dyno came about when other engine shops could not achieve the same power levels with their engines. Besides, many shops just like to hate the local best.

ON your 465, yes, I did notice it was slightly off from the advertised hp level BUT that engine was not yet broken in! Were you there to see the other 465 hit 70hp?? I expect you would see more from it now. By the way, get that 703 over so I can see how "generous" the new dyno is to a Doo.

 

I've had the conversation with the owner of Team Pami about just a bore on a stock bottom end for the DS. While this may make good HP, we are just not satistied with stock reliability. Team Pami refuses to build a motor that will not last, and when the power is increased, we want to up the reliability as well. Our 703 kits include oiling modifications to help insure long life. With the 2MM bore, they want to go into the bottom end, and as long as we are there, lets stroke the crank. The torque gains are worth it.

Another American engine builder has sent several DS motors back to Rotax for "warranty" replacement due to bottom end failures when higher HP levels are achieved. Rotax would now like to find out the engine # of the motors that this manufactuer builds, because they believe that pistons and heads are being swapped back to stock after failure. Team Pami's close relationship with Rotax is the sorce of this info, as at least 7 of these motors were seen by Team Pami reps, in the last few months.

At less than $2400[fully assembled] for a 2MM bore, 3MM stroke, and the oiling mods to help it live a long life, I think that customers will agree, it's the best bang for the buck around. Why sacrifice power and risk reliability, to save a few bucks? If another builder wants to offer a bore, without doing anything to the bottom end, they will not see any competition on this from Team Pami or Knutz Concepts. I wish there customers the best of luck though.

We WON'T build hand grenades!

 

I understand that Knutz. My problem is that I want to do the work myself because I dont not trust my local shop and do not want to wait 6 weeks because they are winterizing jet skis. I just dont know anything about the crank, thats why I have been avoiding it!!!

 

<< 1st let me say that we should take Raptor 720 seriously. I've met hiom and he's really not a crack addict. But Jon are your dyno #'s from the old dyno at trinity, cause I've seen their ad and they advertize the 465 kit at 6hp more than my wife's made. And you were there to see that! My pet name for the DS is SAND PIG! Hey Faster, I run race fuel with the 12.5-1 piston and in my opinion, it starts easier than when it was stock. I only ride sand dunes and wide open Desert. Not too many trees in Vegas. Only problem I am having is oil out the crank case vent. BUT I had that before any mods. >>


Vegas650,oil out of the crankcase vent seems to be a common problem with the rotax 650 motor when pumped up,I am.....and will find some kind of cure some day.I am constantly trying new ideas,the next is Spykes crankcase vent system.I will let you know if it helps.I might just have to abandon the stock vent system,as it only actually vents through a 4 mm hole on the counterbalancer.Making this hole larger would probably weaken the balancer too much,so venting from another location might be needed.
Jeff
Spykes Krankcase venting sytem

 

Keep in mind though Jeff, his motor, like yours, put oil out befor being pumped up.

I wonder if it could be related to break in procedures in some way, I know that you were both racing your bikes the first weekend they were done. I'm not trying to say that you guys goofed them up, just looking for a common link. I just put a piston, cams, carb, and pipe on a brand new Baja[0 hours on it] and it seems to be doing it as well. He was racing it as soon as it was built also.

I broke mine in perfectly, and get almost no oil out the breather.

Not sure these are related, but offering the opinion. I have not heard of any of my other motors having the same problem.

 

Hey knutz me and jeff have spoke of this problem before it is not only pami's mine dose the same crank case presure out every posible hole in the engine. and when jeff solves this problem im frist in line. and in regards to longevity of a top end only mod's it is posible with very dependable results mine is top end only and as vegas will tell you soon.ron woods claims 8'500 rpm and when i leave the line thats where im at. and my mods are quite a bit older than any pami in the states and she runs as good today as she did when she was frist done.and when i walked into my builders shop he guareented me the performance i got. ps guy's the only thing to ever had go wrong on my ds is the fan just went out i took it off and threw it away and i have no fan and no heating problem{note:i live in arizona]any way's not trying to start anything knutz .just giving hurycne a different point of view.


ps i wipe out two there pound bottles of nitrous every time im out. and i run 110 octane nasty fuel

 

No problem AZ, I wasn't trying to start anything either. I was just stating Team Pami's possition on that subject, and why they have that opinion. They have years more experience than I do, so I build what they develope. Had I not had there experience behind me, I would have offered the bored motor. I asked them, the owner of Team Pami relayed to me what I relayed to y'all, so I/we will not do motors like that.

 

Jeff,
The crankcase ventalators on that website appear to be nothing more than elaborate (chromed)pcv valves. If this is the case, all you really need to do is source a generic one from your local autoparts store. After all, its probably going to be out of sight so you certainly dont need to pay for chrome. Plumbing and oil-compatable hose can also be found locally and at a huge savings. Just a thaught.