Ask the Honda VFR750F service manual

The Honda VFR750F is one of those bikes people keep for twenty years. A gear-driven-cam 90° V4 that sounds like nothing else, and enough build quality that plenty of RC36s are still on the road in daily use. What is not still in one piece is the paperwork: the official Honda workshop manual gets passed around owners’ forums as a fuzzy 300-page scan, and finding one number in it means squinting and scrolling.

So I did for the VFR what I had already done for a Yamaha Virago: put the whole manual behind a chatbot you can just ask. It is live, free, and needs no login:

vfr750.edestudio.us

Ask it the valve clearances, how to balance the carbs. It answers from the manual only, shows the exploded diagram next to the answer, and keeps the full PDF a click away.

Screenshot of the Honda VFR750F manual assistant answering “What are the valve clearances?”. The reply gives the intake clearance as 0.13 to 0.19 mm (0.005 to 0.007 in) and the exhaust as 0.22 to 0.28 mm (0.009 to 0.011 in), notes the figures are on page 93 of the Maintenance chapter, and shows an inline exploded diagram of the radiator from the manual page. Below the diagram it cross-references the same specification on page 25, General Information, as a small standard/service-limit table.

What it actually does ¶

You type a question the way you would ask a mate in the garage. It finds the relevant pages of the manual, quotes the exact figures, and tells you which chapter and page they came from so you can open the PDF to that spot and check for yourself.

A few things it is good at:

Specs, verbatim. “What are the valve clearances?” comes back with the cold figures straight from the table: intake 0.13–0.19 mm, exhaust 0.22–0.28 mm. “How much engine oil?” → 2.9 L at a drain. “Fork oil capacity?” → 383 cc on the early bikes, and it flags that the number changed across the production run rather than pretending there is one answer.
Procedures, in order. Carb balancing, brake rebuilds, fork service — it gives the manual’s numbered steps with the warnings and torque values kept in place.
The diagrams. A service manual is half pictures, and they are the half text cannot replace. When an exploded view or a wiring schematic backs up the answer, it shows up inline next to the step it belongs to. The carb vacuum sync question, for example, comes with the spec (within 20 mmHg) and the diagram of where the gauges go.
Knowing when to shut up. If the manual does not cover something, it says so instead of inventing an answer. It is grounded in the manual and nothing else, so it will not cheerfully make up a torque figure from the internet.

Who it is for ¶

‘90–‘96 VFR750F (RC36) owners. The manual covers the whole run, including the early/late split, and the assistant carries those model-year differences through rather than flattening them — the fork oil example above is exactly that. If you are doing your own spannering on one of these and you are tired of pinch-zooming a PDF on your phone in the garage, this is for you.

How it is built ¶

This is the same machine I built for the Virago, pointed at a Honda, so I am not going to re-run the whole technical story here. The short version: a scanned spec manual is only useful if the numbers survive OCR exactly — a torque figure with a missing digit is not a typo, it is an over-tightened brake bolt — and that fidelity is the bar the whole thing is held to. Two earlier posts cover how that gets done and how the diagrams end up inline:

Measuring OCR accuracy for a 1994 service manual RAG — the test that decides whether a corpus is safe to ship.
The local OCR that scored best, and let the chatbot show the diagrams — turning a scan into clean text plus every figure with Docling + RapidOCR.

The OCR is local: Docling with RapidOCR turns the scanned pages into clean Markdown and pulls every figure out as its own image, no hosted API and no per-page cost — it was the most faithful of the local pipelines I tested. The one thing I did differently this time: the manual pages live in Cloudflare AI Search’s built-in storage — you upload the documents straight to the search instance rather than wiring up an external bucket and a sync job. Otherwise it is the Virago build — Cloudflare Pages, AI Search for retrieval, the PDF and figures in R2 — running over a different book.

The honest bit ¶

It only answers from the manual and will admit when it cannot help, which is most of what you want from a tool like this. But it is still a language model. Confirm anything safety-critical — torque values, clearances, fluid types — against the PDF, which is sitting right there in the side panel for exactly that reason. Think of it as a very fast way to find the right page, not a replacement for the manual, and definitely not a replacement for knowing which way to turn the spanner.

Go ask it something: vfr750.edestudio.us . If you run a VFR and it gets something wrong, I want to hear about it.

(And if you have the little Yamaha cruiser in the other half of the garage, its manual got the same treatment: virago.edestudio.us .)