Spray something like WD40 or brake and parts cleaner behind the flywheel towards the bearing while idling. If the engine changes tone or stalls you have a leak.

I believe there is a pretty decent weight difference between the Losi and Durango also so do not forget that it might require a different clutch set up and tune (as in you might need to run a leaner bottom end). Check the front bearing first as it only takes a sec to do so then assuming you are running the correct pipe 2058 or 2013 check gearing, clutch set up and then tune.

yeah we tried heavier and light spring and have messed with tune alot and still nothing. Gearing is correct 13/50 and im running 2013 pipe. So im hoping its a front bearing.

Mike I would go to a 48 spur and let me have a look at the tune please.

If Joe is local, I'd work with him on it as he is really knowledgeable on our engines. I will say though that I have never seen a truggy that a B5 especially when combined with our 2013 has not had the power to push around with authority! I know that you played around with springs but do not discount the impact of the clutch. If the engine is the same & pipe is the same but performance is different then you have to go through a process of elimination and figure out exactly what is different. So fuel, tune, clutch set up (so clutch type, shoes and springs) & gearing.

b5 or b6pro
 

Looking into buying one or the other..
Looking for good run times with a jp1 or jp2 ..
Clocked or not clocked..???

Questions .. questions

Any help appreciated with this choice as im runnin a werks b2 in my t8t and its flying..
So gonna put werks in all the truggys.Really lookin for bottom to mid power.. top end not important as i get that from the b2 with a hyper efra tuned pipe already.

I have a B5 with a 2013 pipe and it has great bottom and mid. Works good with a 2058 pipe also. Not sure what the jp pipes do for this engine. The B6 is more mellow (not weak) on the bottom, but will scream on top with a 2058 pipe....

Thanks for that schultz
Might just buy the b6 pro after reading more of the net..
Probably well suited to our long track.
Besides if it ever stays dry over here i might get to use all the power the b2 gives in the lower range..and for the dry something real quick .. b6 .

If you want something real quick, the B6 (or B6 Pro) with the 2058 will make you very happy.
Strong linear power from start to finish, and insane top end :nod:

Just ran my B5 pro that i got used, fresh repinch, looked great inside. Motor runs amazingly well, few question before tomorrow race. I have a idle gap of 1 ish mm instead of .5 but i am at 7000 fi alttitude, (less oxygen). no big deal idles the whole first tank rich (suprising) and second tank ran at 170 is and needles set rich from flush. The low speed needle is just for idle????? I usually have to lean them to get snap but with this one rich it still has snap, after a few secs it loads up a bit but still has snap.

New Zealand Werks Team Driver Chris Banham takes the Truggy A-Final at a major 3 day event here this weekend.
A large field of top drivers from around the country fought it out in very adverse weather conditions over all three days, on a very heavy and muddy track.
Chris's Werks B5 Pro was impressive all weekend, and showed a clean pair of heels to the field in the A-Final, powering his X-Ray truggy around the heavy track easily :)

Am gonna throw this out there. Just an opinion. I'm thinking your idle gap is to large. I've never experienced big altitude swings with nitro engines, but I have with snowmobiles. That being said, before fuel injection, we would have play with the jetting when going to Colorado. Never would we change the idle settings. A throttle body injected vehicles on board computer adjust the fuel settings, not the idle gap for altitude changes. I guess I would try reducing the I idle gap and lean the lsn accordingly. Hope this helps....

Ran it today only had 2 tanks on the repinch so I ran it easy and a bit rich and it rocked. It is pretty rich until it comes up to temp but once its up to temp look out it rolls out!! cant wait to try this b5 in the buggy. Found out a lot of local guys run the Werks motors :).

Anyone know the dimensions of the shims I would need to put behind the collet to move the flywheel out as the durango flywheel touches the carb housing without shims so I have to order some but not sure what size to get.

Thanks for any help

You are going to have to measure how far forward you need to shim the flywheel which will dictate the thickness or amount of shims that you need to use in the shim stack. I'd just use some calipers to measure that. All .21 external crankshaft diameters are standardized so any .21 clutch shim kit will fit.