Diagnose 1976 BMW R90/6 Stalling

minimum $50 USD / heure

Fermé

Publié il y a 18 jours

minimum $50 USD / heure

My 1976 BMW R90/6 starts easily, idles fine for a couple of minutes, then dies—whether the bike is just sitting, blipping the throttle, or already rolling. I need a seasoned Airhead-savvy mechanic who can work with me remotely to track down the root cause and walk me through the fix. 1976 BMW R90/6 I just purchased on eBay stalls gradually every time after starting in about 3 minutes. By the end, it runs at very low RPM with full throttle, than dies. I rebuilt the carbs and the peatcock, cleaned the tank, but problem still exist. Ignition timing is right on with strong sparks. I measured the compression when the carbs were off and both cylinder gave 150 psi compression. I am out of ideas, there is no vacuum leaks at carbs either. Someone suggested the reason for the stalling in 2 minutes after starting is the piston getting stucked when the engine warming up and the piston is expanding from the heat. I need to take the engine apart to see if the piston skirt has dragmarks on it. Then the cylinder has to be honed and an oversized piston to be installed. The engine is not even broken in, only has 3,500 miles on it. It could have been abused by the first owner and not broke it in as should. What you’ll be tackling • Engine-related stall that appears roughly three minutes after a cold or warm start and repeats consistently, no matter the throttle position. • I can supply live video, photos, compression numbers, carb sync readings, multimeter results—whatever data you ask for. What I’m looking for 1. A systematic diagnostic plan tailored to the R90/6: ignition (points, advance unit, coils), fuel delivery (Bing 64 carbs, petcocks, tank vent), and any temperature-related mechanical quirks. 2. Real-time guidance via chat or video as I perform the checks, adjust settings, or swap parts. 3. A concise summary of each session so I can document what was tested, the outcome, and next steps. 4. Final confirmation run where the bike idles and rides for at least 30 minutes without stalling. If you know these air-cooled boxers inside out and can translate that knowledge through a screen, let’s get my classic back on the road.

Automotive

Mechanical Engineering

N° de projet : 40258570

Concernant le projet

11 propositions

Projet à distance

Actif à il y a 18 jours

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11 freelances proposent en moyenne $59 USD/heure pour ce travail

@Feriver

Hello, I understand your 1976 BMW R90/6 stalls consistently after a few minutes despite carbs, ignition, and compression checks. I will provide a systematic diagnostic plan covering ignition (points, coils, advance), fuel delivery (Bing 64 carbs, petcock, tank vent), and temperature-related mechanical issues like piston expansion. We will work remotely via live video or chat as you perform tests, swap parts, and take readings. I will guide you step by step, flagging anomalies and explaining fixes in real time. Each session will include a concise summary of findings and recommended next steps. Final deliverable: a confirmed, fully running engine with 30+ minutes idle and ride without stalling, plus documented diagnostics for future reference. Client Questions: Do you have access to a full set of feeler gauges and timing tools for on-screen verification? Should we prioritize mechanical checks (piston/cylinder) or rule out ignition/fuel system completely first?

$50 USD en 40 jours

5,0

(6 commentaires)

5,2

@revival786

Greetings! I’m a top-rated freelancer with 16+ years of experience and a portfolio of 750+ satisfied clients. I specialize in delivering high-quality, professional 1976 BMW R90/6 stalling diagnose services tailored to your unique needs. Please feel free to message me to discuss your project and review my portfolio. I’d love to help bring your ideas to life! Looking forward to collaborating with you! Best regards, Revival

$50 USD en 40 jours

5,0

(1 commentaire)

4,1

@omoobasays

Hello, Your 1976 BMW R90/6 symptoms point to a very specific pattern that I’ve seen repeatedly on classic BMW Airheads: a system that runs properly cold, then gradually leans out and dies after a few minutes regardless of throttle position. The fact that it decays slowly(even at full throttle) strongly suggests fuel delivery restriction rather than ignition timing or compression.

$100 USD en 5 jours

5,0

(1 commentaire)

3,5

@irsolutions

With over a decade of experience in motorcycle repair and a specialization in vintage Airhead models like the 1976 BMW R90/6, I understand the frustration of dealing with a persistent stalling issue. Your project outlines a specific challenge that requires a seasoned expert to diagnose and provide real-time guidance remotely. In the past, I have successfully resolved complex engine-related problems similar to yours, ensuring optimal performance and reliability for motorcycle enthusiasts. My hands-on experience with ignition systems, carburetors, and mechanical components aligns perfectly with the requirements of your project. I am confident in my ability to develop a comprehensive diagnostic plan tailored to your R90/6, guiding you through each step to identify and resolve the root cause of the stalling issue. Let's work together to bring your classic BMW back on the road with confidence and reliability. I am ready to provide the expertise and support you need to tackle this challenge effectively. Reach out to me so we can discuss the next steps and get started right away.

$50 USD en 15 jours

0,0

(0 commentaires)

0,0

@juanjosec63

Hello, I’m excited about the opportunity to contribute to your project. With hands-on experience diagnosing classic air-cooled boxer engines and systematic fault isolation in vintage ignition and fuel systems, I can guide you step-by-step to pinpoint the root cause of the 3-minute stall on your R90/6 without jumping straight to a teardown. I’ll tailor the diagnostic plan specifically to the Airhead platform—checking advance unit behavior when warm, coil resistance hot vs cold, condenser breakdown, tank venting, float levels, enrichener circuits, and heat-related fuel starvation—while working with your live data (video, multimeter readings, timing light, carb sync) and documenting each test result clearly. You can expect structured troubleshooting sessions, concise written summaries after each check, and a logical escalation path that rules out electrical and fuel causes before considering mechanical expansion issues, aiming for a confirmed 30-minute stable idle and road test. Best regards, Juan

$50 USD en 40 jours