Big bore
Thread Starter
|
Novice
Joined: Jun 2017
Posts: 24
Likes: 0
From: northern alberta
Big bore
Hi all. I have a bit of a head scratcher here and I hope you all can help - or bounce some ideas around. Stock cylinders, sent them out to a reputable machine shop with new pistons to have cylinders bored. Everything came back, I put rings into bore about an inch down, measured and filed and measured and filed my rings until I got to the required .018" end gap. Pistons are flat top 10.5:1, cams are Fueling 594's, Fueling race oil pump, heads ported and flowed with O/S valves and high lift springs. I am running a Thundermax on this bike so am able to monitor. Here is what happens: I flashed the Tmax with a close map, initialized the Tmax. While Linked, I started my bike...runs amazing!...for about 45 seconds, then it sounds like it starts to labor for about 3 seconds then dies. While running, the target and the actual AFR are almost bang on to each other, then when it starts to labor, the rear cylinder goes slightly lean and then bike dies. Anyone have any ideas/insight/thoughts?
Thanks.
Thanks.
Tourer
Joined: Mar 2010
Posts: 428
Likes: 35
From: Calgary Alberta Canada
What year and model of bike? Check your fuel tank quick disconnect . perhaps its not seated and starving for fuel. Also check battery voltage ins't dropping below master relay voltage or it might not have enough juice to open injectors. Could also be the fuel pump. Do you hear it running at key on and ign switch turned on?
Thread Starter
|
Novice
Joined: Jun 2017
Posts: 24
Likes: 0
From: northern alberta
Thanks for the reply, I had some doubts about voltage etc and went out and bought a battery tender, fully charged the battery, I can hear the fuel pump running. Good point about the fuel disconnect, I did notice it was not correctly hooked up when I first turned bike over...i should check that again. What I am worried about(and I really hope this isn't the case) is that the cylider/piston clearance is not adequate and the piston is expanding and lodging in the bore and stalling the bike. I did not check the clearance measurement when I got the cylinders back as I said...they were bored by a reputable shop. I am well aware that I should have measured them, I just didnt and I am fully prepared for the lashing I may receive on here...haha. I am just trying to get other ideas and possibilities to check before I go that route and pull the cylinders back off...
Road Warrior
Joined: May 2012
Posts: 1,423
Likes: 535
From: Oregon
If you are doing heat cycle break in then 30-45 seconds is all you should run it the first start. After it cools, then the next start should be for 60 seconds. Do this until you reach 3 minutes and then go ride.
You may have a clearance problem, but hope you don't!
You may have a clearance problem, but hope you don't!
Seasoned HDF Member
Joined: Apr 2015
Posts: 6,863
Likes: 3,727
From: St. Charles, MO
Thanks for the reply, I had some doubts about voltage etc and went out and bought a battery tender, fully charged the battery, I can hear the fuel pump running. Good point about the fuel disconnect, I did notice it was not correctly hooked up when I first turned bike over...i should check that again. What I am worried about(and I really hope this isn't the case) is that the cylider/piston clearance is not adequate and the piston is expanding and lodging in the bore and stalling the bike. I did not check the clearance measurement when I got the cylinders back as I said...they were bored by a reputable shop. I am well aware that I should have measured them, I just didnt and I am fully prepared for the lashing I may receive on here...haha. I am just trying to get other ideas and possibilities to check before I go that route and pull the cylinders back off...
Ultimate HDF Member
Joined: Jun 2009
Posts: 6,899
Likes: 3,412
From: OH
You might get more info in the engine and mechanical section if you don't here. That's all i have to conttibute. Good guys in that sectoon. Good luck.
Trending Topics
Seasoned HDF Member
Joined: Apr 2015
Posts: 6,863
Likes: 3,727
From: St. Charles, MO
Maybe check your intake runner gasket; you may have a kink in the gasket that opens up when warmed up.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Tourer
Joined: Nov 2012
Posts: 421
Likes: 71
From: Hayward Ca
If you piston was ceasing up in the cylinder bore and stalling the bike it seems to me you would know it. Your motor is turning at around 1000 RPM and that would make an awful noise.
I usually start by checking the fuel pressure in instances like this. Eliminates any fuel delivery issues up to your injectors. I use the Fuel Tool MC500.
I usually start by checking the fuel pressure in instances like this. Eliminates any fuel delivery issues up to your injectors. I use the Fuel Tool MC500.