Thread: Hitting rev limiter- options
10-20-2012, 04:06 AM #1
Hitting rev limiter- options
With a perfect condition Solas 17/29 impeller and pump housing, running 17.5psi boost I am now tapping on the rev limiter at around 67-68mph on the clock in fresh water. In salt water it is fine.
Do I - replace my 17/29 with an 18/30?
- try and repitch the 17/29 ?
- or attempt to reclock the ecu to shift rev limit, also probably leaning it slightly so may need FPR???
Can anyone actually tell me if the latter is possible and have anecdotal evidence that it will work in a Honda ski without completely throwing injection and timing off
10-20-2012, 09:20 PM #2
You can also put a smaller exit nozzle on it to lower rpms. Btw, how big is the exit nozzle on your ski? Im running a 17/28 honda prop on my yamaha gpr
10-20-2012, 11:20 PM #3
I can tell u (with evidence to back it up ) that ur begin to run lean at 14.5psi (13:1 air fuel ratio) and @ 16psi ur getting into the 15:1 area . .. ur exhaust temps r thru the roof with long wot runs. O and just so I can say I told u. The adjustable fpr will help but for u to run 17.5psi safely u will be going thru plugs fast cause u will be running so rich everywhere except wot. Not to mention ur range will suffer badly.also ur oil will suffer more delution from gas in oil with the added fuel and higher boost . As far as u hitting rev limiter . I was able to stay on limiter only using 15-16psi in the humid summer . Tho I hadseveral other upgrades at the time. I would leave it be and spend my money get ur a/f rite but that's just me
10-21-2012, 10:27 PM #4
Thanks, I havn't got around to the A/F ratio meter yet but it is in the pipeline. I'm not sure of the stock FPR but would a 1:1 rising rate reg eliminate the issue of being rich throughout the low range do you think? I would agree with the "false trickery" that is the macsboost module. ECU thinks it's fuelling 13psi (or whatever) at modified higher levels and why would it like more when it isn't mapped for it. But anyway... cant really accurately comment untill I have the a/f gauge. The nozzle reduction seems a good start
10-22-2012, 10:48 AM #5
The stock fuel table stops at about 14.5 psi either that or injectors r at 100% duty cycle . But I know after 14.5 it starts getting leaner. As far as the fpr the stock one is a 1:1 RR . And the adjustable fpr is also a 1:1 now if they made a 1:1.5 that might solve the lean issue . But u would probably have to change the oil every 20hrs it would be so deluted with gas . ..
06-08-2013, 06:15 PM #6
Hi JLFX. This is my experience with the MTX-L A/F gauge. Did a 108 mile trip yesterday up the coast 40 miles and then up river. Running 17.5psi bleed. O2 mounted in top expansion chamber with stock exhaust, Macs IC, module, 98 gas with Nulon Pro octane boost (which is the only stuff that actually works). At light cruise 5-7psi AF was 14.5. Moderate cruise 10psi AF was 13.8 and at WOT max 69mph 18psi on gauge AF was 12.8. All day I never saw AF go above 14.7. And the 108 mile trip I used 67 litres. One thing I noted was that you could almost was the AF gauge and at a certain point it would jump down basically 1 whole unit as boost increased. I'm not sure if this is the FP reg kicking in or the ecu mapping but I am happy with the results. My ski has done 101 hours
06-12-2013, 08:48 PM #7
I can tell you Ramon has done Hydrodrags verified with only ecu work tweaking and exhaust mods and prop work 76.8 mph.
06-28-2013, 01:54 PM #8
- Join Date
- Jun 2013
Nice saying. As Honda is gaining progress day by day in this type of products. As it is also deserves for it because of bringing new one's and latest one's than its competitors with good mileage.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By Rick Hanley in forum 4-Tec PerformanceReplies: 2Last Post: 07-04-2011, 05:46 PM
By nick34 in forum Polaris Open DiscussionReplies: 10Last Post: 06-05-2010, 10:41 PM
By WAGZ102 in forum 2-Stroke PerformanceReplies: 52Last Post: 06-01-2010, 05:16 AM
By diesel04 in forum 2-Stroke PerformanceReplies: 2Last Post: 09-14-2009, 10:39 AM
By ugadawg131 in forum Kawasaki Open DiscussionReplies: 1Last Post: 06-22-2009, 10:11 PM