Victoria! Zeke's CB175 Build
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Texasstar
Can't is a four letter dirty word
no you had it right technically. The T4 is continuing to make power all the way to the end. We had to call it a day on the Dyno because we have no data for the RPM which is critical. Something is wrong with the equipment. We want to stay at 12-13 because of the heat. I need to check the temp gage for the highest temp. Now the Mr12 power drops off as it gets lean. We will go back to the Dyno with larger jets and see if we make more power but the MR12 data is amazing and it may be in our benefit to go with a lower redline and keep the better acceleration.simo said:So I got that the wrong way around
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Texasstar
Can't is a four letter dirty word
.The Vp rep told me that U4.4 is a blended (watered down) MR12 and we are suppose to make 6-8 % more power than the u4.4 but to do so I think Crazypj maybe right and we may need more carb tuning and maybe intake tract length along with exhaust tuning. However these these pipes are so much fun and it is fun to see everyone's reaction when it is fired up. Michael 'Mercury' Morse told me they have been working on a cb160 turning 14k and making crazy power....Zeke was very proud and ecstatic after this dyno run.
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Texasstar said:T4 made better hp this item up a half of hp to 22.42 edit MR12 made 22.63 while U4.4 made 23.2
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That looks like one run was in 4th and the other in 5th. How else can the speeds be so different with a similar graph shape? The dyno is out of calibration or something is wrong. 19hp at low RPM is just wrong. I realize that was against t (time) but if the revs kept increasing, then it started at low revs and a lot less power - or was that run a constant speed run at close to peak RPM for 7 seconds?
All the runs go lean towards the top end which indicates it need smaller main air jets of a taller spray tube (needle jet). See if you can get a pair for a late model CB750F or F2 check this and others and try to get all 3 common heights to test. Or remove the air jet with an EZ out and measure the jet diameter and have some made in slightly smaller sizes. I may hyave a pair here but I can't lay my hands on a stock one to measure right now to see if I have a pair in a suitable size.
Or go with larger main jets and allow it to run a little rich at lower revs.
Have you "ported" the fuel intakes above the needle jets and do you have enough fuel flow to support say 30Hp (play safe) at say 14,000 at say 7 pounds of fuel per hour per HP? It may just be running the float bowls dry
Texasstar
Can't is a four letter dirty word
yes this dyno sheet was a 4th and 5th gear run for the same fuel...the t4 fuel but my comment made it confusing because I was thinking and typing out loud.teazer said:
No we haven't ported above the needle but you did on one of the carbs so I need to go do the other carb since I have a template to go by.
Would the vibration cause fuel to dump from the float bowls??? Zeke told me he thought he saw fuel coming out of the overflow tube on one carb. I went back and listened to the video I posted above and that was for the MR12 and yes you are right there are 3 runs that that match the dyno data where the dyno brake isn't working. You can here him roll off the throttle and back on. Without the rpms this is futile.
Here is the data and dyno from the second run with the Mr12
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