R1-Z back from the dyno

[kernow]

Picked up the R1-Z 250 last week from the dyno. The jetting was all over the place, way to big pilots and others blocked. With the recently fitted Zeeltronic, mild porting and a set of spannies we got 46bhp at the back wheel and 51 at the crank. Justin did remark more could be achieved with different spannies but it would be top end and loose some of the lower midrange. Managed to get a short ride before lockdown and the bike pulls well, really good lower and mid range, the top end i could not test with traffic etc. So really pleased as its been a while. 
One thing did show up the temperature gauge is not working, i have ordered a new sensor. Any other areas i should look to if that does not cure it, are the gauges troublesome?
Cheers all stay safe
Bry

[beardy]

Impressive. Probably more powerful than my 4lo

[bare]

Yamaha steadfastly Claimed 47 hp for their 4lo bikes They lied tho ... it's a Yamaha tradition.

[pdxjim]

Makes me feel better about my poorly set up TDR pulling 40hp at the wheel.

Since then, I've done a Zeel ignition and leaned out the jetting a bit.

Plan is to get both the TDR and LC on the dyno within a few month time.

Congrats on the good pull, kernow 👍👍

[kernow]

Jan 14, 2021 2:12:28 GMT 1 pdxjim said:

Makes me feel better about my poorly set up TDR pulling 40hp at the wheel.

Since then, I've done a Zeel ignition and leaned out the jetting a bit.

Plan is to get both the TDR and LC on the dyno within a few month time.

Congrats on the good pull, kernow 👍👍

Thanks. It's been a long time to get it running well but it feels like it's going to be a good result. Just got to sort the temperature gauge and look forward to the spring for some better weather and hopefully get on top of this horrible pandemic

[loudy]

I've never visited a Dyno. I'm curious as to how and why they measure from both the back wheel and crank? Did they cobble some sort of fittings together to drive the Dyno from the flywheel??

[midlifecrisisrd]

Not 100% sure but seem to remember a mates car on a dyno and there was a calculation done on the transmission drag

Steve

[loudy]

Jan 14, 2021 19:40:55 GMT 1 midlifecrisisrd said:

Not 100% sure but seem to remember a mates car on a dyno and there was a calculation done on the transmission drag

Steve

I assume that there are a good many variables with this calculation - o ring or non o ring chain, tyre width and pressure etc...

[copper99]

Jan 14, 2021 19:40:55 GMT 1 midlifecrisisrd said:

Not 100% sure but seem to remember a mates car on a dyno and there was a calculation done on the transmission drag

Steve

I witnessed a big old Yank tank on a dyno, sort of thing Fozzy Bear drove around in from Starsky and Hutch!

Dyno man had the transmission losses at around 100BHP!

[copper99]

Mutts got my 350LC up from 39RWHP to 46 RWHP with some setting up and power dynamo...only mods on my bike being "Nospeeds" and the airbox snorkel removed.

[midlifecrisisrd]

A lot of heavy bits in those big yank jobbies but 100hp is mental

When you think about it if you dip the clutch the dyno will know it's own spin down rate so should give a negative hp reading for the drag

Steve

[muttsnuts]

On a decent dyno you can do tests to work out the transmission losses, I don't do it on old 2 strokes as it requires the clutch to be pulled in at max revs and kept held in until the rear wheel stops spinning, if you try and do this on an LC or YPVS you'll end up with a welded clutch pushrod to the ball bearing and the actuator arm (on a YPVS anyway), which then necessitates a full engine strip down to seperate and remove all the welded parts !

Yes, my dyno can do this test, and I have done it on my own kit, but won't do it on a customers, not unless they are happy to run the risk of the above happening......